Pfizer announced Saturday that tweaking its COVID-19 vaccine to better target the omicron variant is safe and works — just days before regulators debate whether to offer Americans updated booster shots this fall.

The vaccines currently used in the U.S. still offer strong protection against severe COVID-19 disease and death -- especially if people have gotten a booster dose. But those vaccines target the original coronavirus strain and their effectiveness against any infection dropped markedly when the super-contagious omicron mutant emerged.

Now with omicron's even more transmissible relatives spreading widely, the Food and Drug Administration is considering ordering a recipe change for the vaccines made by both Pfizer and rival Moderna in hopes that modified boosters could better protect against another COVID-19 surge expected this fall and winter.

Pfizer and its partner BioNTech studied two different ways of updating their shots -- targeting just omicron, or a combination booster that adds omicron protection to the original vaccine. They also tested whether to keep today's standard dosage -- 30 micrograms -- or to double the shots' strength.

In a study of more than 1,200 middle-aged and older adults who'd already had three vaccine doses, Pfizer said both booster approaches spurred a substantial jump in omicron-fighting antibodies.

"Based on these data, we believe we have two very strong omicron-adapted candidates," Pfizer CEO Albert Bourla said in a statement.

Pfizer's omicron-only booster sparked the strongest immune response against that variant.

But many experts say combination shots may be the best approach because they would retain the proven benefits of the original COVID-19 vaccine while adding new protection against omicron. And Pfizer said a month after people received its combo shot, they had a 9 to 11-fold increase in omicron-fighting antibodies. That's more than 1.5 times better than another dose of the original vaccine.

And importantly, preliminary lab studies show the tweaked shots also produce antibodies capable of fighting omicron's genetically distinct relatives named BA.4 and BA.5, although those levels weren't nearly as high.

Moderna recently announced similar results from tests of its combination shot, what scientists call a "bivalent" vaccine.

The studies weren't designed to track how well updated boosters prevented COVID-19 cases. Nor is it clear how long any added protection would last.

But the FDA's scientific advisers will publicly debate the data on Tuesday, as they grapple with whether to recommend a change to the vaccines' recipes -- ahead of similar decisions by other countries.

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The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute's Department of Science Education. The AP is solely responsible for all content.

The U.S. Centers for Disease Control and Prevention said Friday that there is a possible safety issue with the bivalent COVID-19 vaccine made by Pfizer and BioNTech but that it is unlikely to represent a true risk.

Video above: Doctor discusses drop in child vaccination rates

The agency said it continues to recommend that people stay up-to-date with COVID-19 vaccines.

The CDC said one of its vaccine safety monitoring systems — a "near real-time surveillance system" called the Vaccine Safety Datalink — detected a possible increase in a certain kind of stroke in people 65 and older who recently got one of Pfizer's updated booster shots.

A rapid response analysis of that signal revealed that seniors who got a bivalent booster might be more likely to have ischemic strokes within the first three weeks after their shots, compared with weeks four through six.

Ischemic strokes, the most common form, are blockages of blood to the brain. They're usually caused by clots.

The Vaccine Safety Datalink, or VSD, is a network of large health systems across the nation that provides data about the safety and efficacy of vaccines through patients' electronic health records. The CDC said it had identified possible confounding factors in the data coming from the VSD that may be biasing the data and need further investigation.

Of about 550,000 seniors who got Pfizer bivalent boosters and were tracked by the VSD, 130 had strokes in the three weeks after the shot, according to a CDC official who spoke to CNN on condition of anonymity because they weren't authorized to share the data. None of the 130 people died.

The number of strokes detected is relatively small, said Dr. William Schaffner, an infectious disease expert at Vanderbilt University and a member of the CDC Advisory Committee on Immunization Practices' COVID-19 Vaccine Work Group.

"These strokes are not a confirmed adverse event at the moment," he said. "It's like a radar system. You're getting a blip on the radar, and you have to do further investigation to discover whether that airplane is friend or foe."

The same safety signal has not been detected with the bivalent Moderna booster, the CDC said in its notice.

The agency noted that it has looked for and failed to find the same increase in strokes in other large collections of medical records, including those maintained by Medicare, the U.S. Department of Veterans Affairs, as well as its Vaccine Adverse Event Reporting System, known as VAERS.

Neither Pfizer nor other countries that are using the vaccine have seen any increase in this kind of stroke, the agency said, and the signal was not detected in any other databases.

The CDC says that it does not recommend any change to vaccination practices at this time and that the risks of COVID-19 for older adults continue to outweigh any possible safety issues with the vaccine.

"Although the totality of the data currently suggests that it is very unlikely that the signal in VSD represents a true clinical risk, we believe it is important to share this information with the public, as we have in the past, when one of our safety monitoring systems detects a signal," the notice says.

"CDC and FDA will continue to evaluate additional data from these and other vaccine safety systems. These data and additional analyses will be discussed at the upcoming Jan. 26 meeting of the FDA's Vaccines and Related Biological Products Advisory Committee."

Pfizer said in a statement Friday, "Neither Pfizer and BioNTech nor the CDC or the U.S. Food and Drug Administration (FDA) have observed similar findings across numerous other monitoring systems in the U.S. and globally and there is no evidence to conclude that ischemic stroke is associated with the use of the companies' COVID-19 vaccines.

"Compared to published incidence rates of ischemic stroke in this older population, the companies to date have observed a lower number of reported ischemic strokes following the vaccination with the Omicron BA.4/BA.5-adapted bivalent vaccine."

The bivalent boosters from Pfizer/BioNTech and Moderna protect against the original strain of the coronavirus as well as the Omicron BA.4 and BA.5 subvariants. Only about 50 million Americans ages 5 and up have gotten them since they were authorized last fall, according to CDC data.

Schaffner said he was part of a briefing Thursday with members of the COVID-19 Vaccine Work Group. He couldn't share specific details about the briefing but said the safety signal was discussed.

His biggest takeaway was that the safety surveillance system is working.

It's very likely that this is a false signal, he said, but it's being investigated, which is important.

"You want a surveillance system that occasionally sends up false signals. If you don't get any signals, you're worried that you're missing stuff."

Schaffner said he would absolutely tell people to get their COVID-19 booster if they haven't done so yet — even those 65 and older.

"Undoubtedly, the risk of a whole series of adverse events, including hospitalization, is much, much greater with COVID-19 than it is from the vaccine," he said.

He also said the signal — if real — may be more a factor of numbers than an indication that one manufacturer's vaccine is riskier than the other.

Nearly two-thirds of the people in the U.S. who've gotten an updated booster — 32 million — have gotten Pfizer, compared with about 18 million Moderna shots.

WASHINGTON —

Federal health regulators on Friday delayed next week's public meeting to review Pfizer’s COVID-19 vaccine for children under 5, saying they want to see more data.

The surprise announcement by the Food and Drug Administration raises questions about how soon youngsters could get the shots. The FDA's outside experts were set to evaluate the first data on COVID-19 vaccinations in toddlers and babies.

The FDA said Pfizer has new data available from its ongoing vaccine study — and the agency needs more time to evaluate it.

The expert panel had been scheduled to meet Tuesday to determine if children under 5 should start getting extra-low doses of Pfizer’s vaccine before it’s clear if they’ll need two shots or three.

The nation’s 18 million children under 5 are the only age group not yet eligible for vaccination. The FDA had pushed Pfizer and its partner BioNTech to apply for authorization of its extra-low doses for tots before final study data was in, as the hugely contagious omicron variant took a toll on children.

This is a developing story and will be updated.

Both vaccination and prior infection help protect against new COVID-19 infections, but vaccination protects against hospitalization significantly more than natural immunity from prior infection alone, according to a study published Wednesday by the U.S. Centers for Disease Control and Prevention.

Researchers analyzed the risk of COVID-19 infection and hospitalization among four groups of individuals: vaccinated with and without prior infection and unvaccinated with and without prior infection. The study case data from about 1.1 million cases in California and New York between the end of May and mid-November 2021. Hospitalization data was available from California only.

Overall, COVID-19 case and hospitalization rates were highest among unvaccinated people who did not have a previous diagnosis.

At first, those with a prior infection had higher case rates than those who were vaccinated with no history of prior infection. As the delta variant became predominant in the U.S. in later months, this shifted and people who survived a previous infection had lower case rates than those who were vaccinated alone, according to the study.

Tracking the omicron surge

"Experts first looked at previous infections confirmed with laboratory test by the spring of 2021, when the alpha variant was predominant across the country. Before the delta variant, COVID-19 vaccination resulted in better protection against a subsequent infection than surviving a previous infection. When looking at the summer and the fall of 2021, when delta became dominant in this country, however, surviving a previous infection now provided greater protection against subsequent infection than vaccination," Dr. Benjamin Silk, lead for CDC's surveillance and analytics on the Epi-Task Force, said on a call with media Wednesday.

However, this shift coincides with a time of waning vaccine immunity in many people. The study did not factor the time from vaccination — and potential waning immunity — into the analysis. The study also does not capture the effect booster doses may have and was conducted before the emergence of the omicron variant.

Throughout the period of the study, risk of COVID-19 hospitalization was significantly higher among unvaccinated people with no previous COVID-19 diagnosis than any other group.

"Together, the totality of the evidence suggests really that both vaccination and having survived COVID each provide protection against subsequent reinfection, infection and hospitalization," said Dr. Eli Rosenberg, New York State Deputy Director for Science. "Having COVID the first time carries with it significant risks, and becoming vaccinated and staying up-to-date with boosters really is the only safe choice for preventing COVID infection and severe disease."

Experts also noted that characteristics of variants change, including how well they affect immunity from prior infections.

The CDC said in a statement it will publish additional data on COVID-19 vaccines and boosters against the dominant omicron variant later this week.

Data from the Centers for Disease Control shows, as of Jan. 1, only about 40% of pregnant women have been vaccinated against COVID-19.

A new study out of Scotland is shining a much larger light on the benefits and safety of getting vaccinated while pregnant.  

More pregnant mothers are weighing whether to get the vaccine, especially with the surging omicron variant.

"I didn't want to get it and potentially harm my baby but looking back, that doesn't really make any sense because I obviously wouldn't have wanted to get COVID with the baby," Heaven Taylor-Wynn said. 

Doctors are trying to convince their pregnant patients to get the vaccine because they are seeing rough outcomes in some unvaccinated pregnant women and their babies. 

"I felt like there was a herd of elephants on my chest, and I couldn't breathe," Ashley Duque said.

"I've seen women they got really bad preeclampsia and a funny variant of preeclampsia called help syndrome that makes them very, very, very sick and requires urgent delivery," said Dr. Brad Holbrook, maternal fetal medicine specialist at Community Medical Center.

"I've seen women with stillbirths. I've seen babies die after they were born," she added.

The study out of Scotland confirms everything doctors like Holbrook have been saying,

The Scotland team studied all women who were pregnant or became pregnant from December 2020 through October 2021. 

"They looked at the entire population of the whole country and because they have a whole, you know, an integrated system," Dr. Holbrook said. "They have 130,000 women in this study that essentially showed the same things, which is that, that women who get COVID are potentially in for some problems. So women who get COVID are more likely to have a pre-term delivery, a stillbirth complication with baby or with their pregnancy, and that women who are vaccinated and then get sick with COVID are very likely to have a much more mild course, so it really just confirmed everything that we've seen."

Among unvaccinated women, the study found they made up 77.4% of COVID infections. They accounted for 90.9% of cases that required hospitalization or critical care, and all 450 fetal and newborn deaths associated with the virus. The rate of deaths in babies after 28 weeks was much higher in women who got COVID-19 within a month of giving birth.  

"The risk of getting infected is pretty high, and the risks involved in being vaccinated are almost nonexistent," said Dr. Alisa Kachikis, assistant professor of maternal fetal medicine at University of Washington.

"I do feel like when I can sit down and talk with them face-to-face about it, look, you know, I'm not representing a drug company," Dr. Holbook said. "I'm not representing the government. I'm just representing the science and what I've read and understand about this and my own experience and based on that and what I've seen, I've seen a lot of complications from COVID."

The highly-transmissible omicron variant brings new concerns, especially in places just starting to experience the surge, like Montana.

"We're gonna have this big bunch of pregnant women come in really sick with COVID and not just pregnant women, unpregnant people as well coming into the hospital, and the hospital is gonna be totally full and understaffed," Dr. Holbrook said. "It's gonna be a very difficult couple of weeks, I think."

This story was originally reported on Newsy.com.

The U.S. is urging that everyone 12 and older get a COVID-19 booster as soon as they're eligible, to help fight back the hugely contagious omicron mutant that's ripping through the country.

Boosters already were encouraged for all Americans 16 and older, but Wednesday the Centers for Disease Control and Prevention endorsed an extra Pfizer shot for younger teens — those 12 to 15 — and strengthened its recommendation that 16- and 17-year-olds get it, too.

"It is critical that we protect our children and teens from COVID-19 infection and the complications of severe disease," Dr. Rochelle Walensky, the CDC's director, said in a statement Wednesday night.

"This booster dose will provide optimized protection against COVID-19 and the Omicron variant. I encourage all parents to keep their children up to date with CDC's COVID-19 vaccine recommendations," she said.

Vaccines still offer strong protection against serious illness from any type of COVID-19, including omicron — what experts say is their most important benefit. But the newest mutant can slip past a layer of the vaccines' protection to cause milder infections. Studies show a booster dose at least temporarily revs up virus-fighting antibodies to levels that offer the best chance at avoiding symptomatic infection, even from omicron.

Earlier Wednesday, the CDC's independent scientific advisers wrestled with whether a booster should be an option for younger teens, who tend not to get as sick from COVID-19 as adults, or more strongly recommended.

Giving teens a booster for a temporary jump in protection against infections is like playing whack-a-mole, cautioned CDC adviser Dr. Sarah Long of Drexel University. But she said the extra shot was worth it to help push back the omicron mutant and shield kids from the missed school and other problems that come with even a very mild case of COVID-19.

More important, if a child with a mild infection spreads it to a more vulnerable parent or grandparent who then dies, the impact "is absolutely crushing," said panelist Dr. Camille Kotton of Massachusetts General Hospital.

"Let's whack this one down," agreed Dr. Jamie Loehr of Cayuga Family Medicine in Ithaca, New York.

The vaccine made by Pfizer and its partner BioNTech is the only option for American children of any age. The CDC says about 13.5 million children ages 12 to 17 — slightly more than half of that age group — have received two Pfizer shots. Boosters were opened to the 16- and 17-year-olds last month.

Wednesday's decision means about 5 million of the younger teens who had their last shot in the spring are eligible for a booster right away. New U.S. guidelines say anyone who received two Pfizer vaccinations and is eligible for a booster can get it five months after their last shot, rather than the six months previously recommended.

But one committee member, Dr. Helen Keipp Talbot of Vanderbilt University, worried that such a strong recommendation for teen boosters would distract from getting shots into the arms of kids who have not been vaccinated at all.

The advisers saw U.S. data making clear that symptomatic COVID-19 cases and hospitalizations are between seven and 11 times higher in unvaccinated adolescents than vaccinated ones.

While children do tend to suffer less serious illness from COVID-19 than adults, child hospitalizations are rising during the omicron wave — the vast majority of them unvaccinated.

During the public comment part of Wednesday's meeting, Dr. Julie Boom of Texas Children's Hospital said a booster recommendation for younger teens "cannot come soon enough."

The chief safety question for adolescents is a rare side effect called myocarditis, a type of heart inflammation seen mostly in younger men and teen boys who get either the Pfizer or Moderna vaccines. The vast majority of cases are mild — far milder than the heart inflammation COVID-19 can cause — and they seem to peak in older teens, those 16 and 17.

The FDA decided a booster dose was as safe for the younger teens as the older ones based largely on data from 6,300 12- to 15-year-olds in Israel who got a Pfizer booster five months after their second dose. Israeli officials said Wednesday that they've seen two cases of mild myocarditis in this age group after giving more boosters, 40,000.

Earlier this week, FDA vaccine chief Dr. Peter Marks said the side effect occurs in about 1 in 10,000 men and boys ages 16 to 30 after their second shot. But he said a third dose appears less risky, by about a third, probably because more time has passed before the booster than between the first two shots.

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The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute's Department of Science Education. The AP is solely responsible for all content.

The Food and Drug Administration will likely authorize Pfizer's COVID-19 booster shot for adolescents aged 12 to 15 by next week, The Washington Post and The New York Times reported on Thursday.

The Pfizer vaccine would be the first booster shot to receive emergency authorization for young teens and pre-teens.

Pfizer's COVID-19 vaccine was approved for use in adolescents in May, and the CDC has recommended adults seek a booster shot six months after their final dose. Should that recommendation carry over to adolescents, many would be eligible for a booster immediately upon approval.

The impending decision comes as the U.S. deals with a surge in COVID-19 cases caused by the highly contagious omicron variant. While the new strain has shown to be slightly more resistant to vaccines, health officials say vaccines and booster shots offer significant protection against severe disease and death.

Pfizer said Friday it was changing plans and testing three doses of its COVID-19 vaccine in babies and preschoolers after the usual two shots didn't appear strong enough for some of the children.

Pfizer announced the change after a preliminary analysis found 2- to 4-year-olds didn't have as strong an immune response as expected to the very low-dose shots the company is testing in the youngest children.

It's disappointing news for families anxious to vaccinate their tots. Pfizer had expected data on how well the vaccines were working in children under 5 by year's end, and it's not clear how long the change will delay a final answer.

Pfizer and its partner BioNTech said if the three-dose study is successful, they plan to apply for emergency authorization sometime in the first half of 2022.

A kid-sized version of Pfizer’s vaccine already is available for 5- to 11-year-olds, one that’s a third of the dose given to everyone else 12 and older.

For children younger than 5, Pfizer is testing an even smaller dose, just 3 micrograms or a tenth of the adult dose.

Researchers analyzed a subset of youngsters in the study a month after their second dose to see if the tots developed levels of virus-fighting antibodies that were similar to teens and young adults who get the regular shots.

The very low-dose shots appeared to work in youngsters under age 2, who produced similar antibody levels. But the immune response in 2- to 4-year-olds was lower than the study required, Pfizer vaccine research chief Kathrin Jansen said Friday in a call with investors.

Rather than trying a higher-dose shot for the preschoolers, Pfizer decided to expand the study to evaluate three of the very low-dose shots in all the study participants — from 6 months up to age 5. That third shot will come at least two months after the youngsters' second dose.

No safety concerns have been spotted in the study, the companies said.

Jansen cited other data showing a booster shot for people 16 and older restores strong protection, a jump in immunity that scientists hope also will help fend off the new omicron variant.

The companies also are preparing to test a booster for 5- to 11-year-olds, who are just now getting their two-dose vaccinations. And they are testing different dose options for teen boosters.

Jansen said if the additional pediatric testing is successful, "we would have a consistent three-dose vaccine approach for all ages."

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The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.

Pfizer and BioNTech reported Friday that studies show children aged between 2 those younger than 5 did not produce an adequate response to its COVID-19 vaccine for young children and that it will begin administering a third dose to those trial participants as studies continue.

In a press release, Pfizer noted that the dose for young children, which is one-tenth the strength of its vaccine for people aged 16 and up, provided the same amount of protection the adult vaccine provides to people aged 16 to 25. However, children aged between 2 and 4 did not produce an adequate response.

"Compared to the 16- to 25-year-old population in which high efficacy was demonstrated, non-inferiority was met for the 6- to 24-month-old population but not for the 2- to under 5-year-old population in this analysis," Pfizer's press release said.

The third shot for children aged 2 to 4 will be administered at least two months after the final shot.

The company added that trials so far had not produced any safety concerns. They noted that the trial studies would remain double-blinded when adding a third dose.

Pfizer made the announcement Friday, the same day that it announced it would be seeking full authorization for the use of its COVID-19 vaccine in adolescents as young as 12.

Pfizer's vaccine is fully approved for people as young as 16, and available through emergency use authorization for kids as young as 5.

Pfizer and BioNTech on Friday announced that they had asked the Food and Drug Administration to grant full approval to their COVID-19 vaccine for use in adolescents as young as 12.

The companies added in a press release that they would also file similar applications with the European Medicines Agency and "other regulatory authorities around the world" in the weeks ahead.

The Pfizer vaccine is already available for adolescents under emergency use authorization, though the shots have been granted full FDA approval for everyone aged 16 and up.

Pfizer's vaccine remains the only anti-COVID-19 shot to receive full FDA approval. Moderna applied for full approval for its COVID-19 vaccine for use in adults in August, though the agency is still weighing the application.

According to the Centers for Disease Control and Prevention, 83% of Americans aged 12 and older have gotten at least one dose of a COVID-19 vaccine. About 71% of those 12 and older are fully vaccinated.

Vaccine advisers to the U.S. Centers for Disease Control and Prevention voted 15-0 Thursday to change recommendations for COVID-19 vaccines to make clear that shots made by Moderna and Pfizer/BioNTech are preferred over Johnson & Johnson's vaccine.

The new recommendation: "mRNA vaccines are preferred over the Janssen COVID-19 vaccine for the prevention of Covid-19 for those 18 years of age and over."

Related video above: Omicron spreads 70 times faster than delta in certain respiratory tissue, researchers say

The CDC's Advisory Committee on Immunization Practices endorsed the updated recommendation after hearing new data indicating that a rare blood clotting syndrome is more common among people who recently got a J&J vaccine than previously believed. The CDC has logged 54 cases in the U.S. of thrombosis with thrombocytopenia syndrome or TTS in the U.S. since the vaccine became available. Nine people have died -- seven women and two men.

ACIP members considered the new data and weighed it against numerous studies showing J&J's vaccine is less effective than the Moderna and Pfizer/BioNTech vaccines in preventing infection. They also discussed the risks of completely removing J&J's vaccine as an option, as well as the potential confusion and mistrust that might be caused by changing recommendations about the vaccine.

"We will absolutely emphasize how important education around the risk of these events is," the CDC's Dr. Sara Oliver told the meeting.

Earlier this week, the U.S. Food and Drug Administration strengthened language in the fact sheet that goes along with the Janssen vaccine, saying it should not be given to anyone with a history of TTS.

The U.S. is expanding COVID-19 boosters, opening a third dose of Pfizer's vaccine to people as young as age 16.

The U.S. and many other nations already urge adults to get a booster to pump up their immunity months after initial vaccination.

In the U.S., the Pfizer vaccine is the only option for children and teenagers.

The Food and Drug Administration on Thursday cleared an extra dose for those ages 16 and 17, and the Centers for Disease Control and Prevention rapidly endorsed a booster for those ages.

"Today, CDC is strengthening its booster recommendations and encouraging everyone 16 and older to receive a booster shot," CDC Director Dr. Rochelle Walensky said in a press release. "Although we don’t have all the answers on the Omicron variant, initial data suggests that COVID-19 boosters help broaden and strengthen the protection against Omicron and other variants."

The CDC recommends that the booster be received six months after their second COVID vaccine shot.

It's not clear if younger teens will need one.

Pfizer said Tuesday it signed a licensing agreement to allow broader global access to its experimental COVID-19 pill.

The agreement with the Medicines Patent Pool, a United Nations-backed public health organization, would allow generic manufacturers to make the pill widely available in 95 low- and middle-income countries covering 53% of the world's population, the company said.

The pill, known as PF-07321332 or Paxlovid, is to be given in combination with an older antiviral drug called ritonavir.

Earlier this month Pfizer announced topline results from its trial saying that an interim analysis — done before the trial was scheduled to end — showed an 89% reduction in the risk of hospitalization or death from COVID-19 among people given the drug within the first three days of symptom onset.

"Pfizer will not receive royalties on sales in low-income countries and will further waive royalties on sales in all countries covered by the agreement while COVID-19 remains classified as a Public Health Emergency of International Concern by the World Health Organization," Pfizer said in the statement.

The Medicines Patent Pool, founded by Unitaid 10 years ago, facilitates rapid access to medicines for people in low- and middle-income-countries.

Pfizer has yet to submit the pill for authorization by the U.S. Food and Drug Administration but said it would do so before the end of the month.

Late last month, Merck, Ridgeback Biotherapeutics and the Medicines Patent Pool announced a voluntary licensing agreement to help create broader access to the antiviral molnupiravir in 105 low- and middle-income-countries.

Molnupiravir is an oral COVID-19 antiviral for treatment of mild to moderate COVID-19 by adults who are at risk of severe COVID-19 and hospitalization. It was authorized by the UK Medicines and Healthcare Products Regulatory Agency earlier this month, and the companies have requested authorization from the US FDA.

Merck, Ridgeback Therapeutics and Emory University — the creators and license holders of the antiviral — will not receive royalties for these sales for the length of time that COVID-19 remains a Public Health Emergency of International Concern under World Health Organization classifications, they said.

CINCINNATI —

There's another potential game-changer in the fight against this pandemic.

Pfizer has now applied for Food and Drug Administration emergency authorization for its COVID-19 antiviral pill.

The pill is made for people who have already been diagnosed with COVID-19, are unvaccinated and at a high risk for becoming severely ill.

The pill would be sold under the brand name Paxlovid, and if granted, could be available in just weeks.

In a clinical trial with adults 18 and up, Pfizer found its antiviral pill cuts hospitalization and death risks by nearly 90 percent when taken within three days of onset symptoms.

Most COVID-19 treatments right now require an IV or injection.

Great Britain authorized Merck's COVID-19 pill earlier this month, and it's pending approval here in the United States.

The US government is expected to cover the cost for both medications, estimated to be around $700 per treatment.

Side effects of this pill were mild to moderate according to Pfizer.

Both Pfizer's pill and Merck's pill attack the coronavirus by interfering with the ability to replicate itself.

CINCINNATI —

Now that kids 5-11-year-olds have the OK to get their COVID-19 shot, a local doctor spoke with WLWT to answer some of your pressing questions, especially for parents who may still be on the fence.

Associate dean of graduate medical education at the UC College of Medicine, Dr. Lou Edje, said a major question she has gotten is, "should I wait and see how others respond first before getting my child the shot?"

"This has been tested, the FDA does not move lightly, the CDC doesn't move lightly, all of the folks that have been in charge of deciding whether this is safe and what the schedule should be are very very careful," Edje said.

That's why she said there's no need for delay.

Another concern causing families to pause: Will the vaccine cause infertility in children years down the line?

Dr. Edje said every person's DNA is stored in the nucleus of their cells.

"It's like a safety deposit box there's absolutely no way that the mRNA in the Pfizer or Moderna vaccines can get into that space, so that means the DNA is not going to be altered, it's not going to alter fertility for our pregnant women," Edje said.

Because COVID-19 reactions are usually mild in children, some ask, "Why is it necessary to vaccinate my child if they probably won't get very sick?"

To that, Edje said the vaccine is effective, it is safe, and it is practical for many families.

"Because if a vaccinated kid gets exposed to COVID, they don't have to be in quarantine, so I as a parent do not have to take multiple unscheduled days off," Edje said.

And, what about the side effects for kids?

Edje said for 5 to 11-year-olds, the Pfizer dose is a third of the size given to adults and children 12 and older, so symptoms are milder.

"Those would include possibly mild fever, fatigue, muscle aches body aches and possibly a mild headache," Edje said.

WASHINGTON — The FDA on Friday issued emergency approval for a smaller dose version of Pfizer's COVID-19 vaccine for use in children aged 5 to 11.

The agency's decision comes just days after the Vaccines and Related Biological Products Advisory Committee voted 17-0 (with one doctor abstaining) to recommend the shots.

"The tremendous cost of this pandemic has not just been in physical illness, it's been in the psychological the social development of children," said Dr. Peter Marks, director of the Center for Biologics Evaluation and Research at the FDA.

The Centers for Disease Control and Prevention (CDC) is scheduled to consider the shots early next week. The agency's Advisory Committee on Immunization Practices must first give its own recommendation before agency director Dr. Rochelle Walensky gives final approval.

Officials estimate that the vaccines could be available to children as early as the first or second week in November.

Last week, the White House said that if and when Pfizer's vaccine receives full emergency use authorization, it would begin shipping 15 million vaccine doses to clinics around the country for immediate distribution.

Biden Administration officials say the country currently has enough doses on hand to vaccinate every child aged between 5 and 11 that lives in the U.S. The White House says that it will primarily lean on primary care doctors and pharmacies to distribute the vaccines but noted that it is also working with some school boards to offer doses in schools.

Pfizer's COVID-19 vaccine has been fully approved by the FDA for everyone aged 16 and up. The shots are also available for adolescents between the age of 12 and 15 on an emergency use basis.

Marks said the FDA is "probably a few months" away from reviewing data for COVID-19 vaccines for younger children.

CINCINNATI —

The U.S. Food and Drug Administration's advisory panel has voted to allow emergency use authorization of Pfizer's shot in kids ages 5 to 11.

Shots could start in a matter of days if the FDA and Centers for Disease Control and Prevention go ahead with committee recommendations. Of the 18 voting members, it was unanimous with 17 yes votes and one abstention.

"Based on the totality of the evidence, the benefits do outweigh the risks,” NCIRD Chief Medical Officer Amanda Cohn said.

The FDA panel recommends Pfizer’s two shots 21-days apart, at one-third the dose given to other Americans. Pfizer's data shows its vaccine is more than 90% effective at preventing severe symptomatic infections. Dr. Chris Peltier with Pediatric Associates of Mt. Carmel and is the president of the Ohio chapter of the American Association of Pediatricians, says it has been a long wait.

“In a word, relief. We've been waiting on this for a while now. So, this is a huge group of patients 5 to 11-year-olds that have not been able to have access to the vaccine which means they are at risk for getting COVID,” Peltier said.

While the vaccine has been shown to cause rare cases of a mild inflammation of the heart in some older teens and young adults, there were no documented cases in the study of 5 to 11-years-old. Doctors say the risk is higher from getting COVID-19 along with other impacts in day-to-day life.

“In addition and probably on a bigger scale, even though kids aren't getting as sick from COVID, if they're getting COVID they're having to miss school,” Peltier said.

A recent poll shows only a third of parents plan to get their children vaccinated right away. That's worrying for many doctors who say vaccinating elementary-aged kids will be key in getting the pandemic under control for good. Peltier says the orders are already on standby for our area.

“Actually, through the state of Ohio, the Ohio Department of Health, many pediatricians, including my practice, we have already placed our first order for the vaccine," he said.

Peltier, not only recommends getting the vaccine, but says to go ahead and call your pediatrician to see if they'll have it available. If they don't, he says to check around for vaccine clinics which are already being worked on.

It's now up to the FDA to decide whether to follow the advisory committee's recommendation. A CDC committee will meet next week to also decide on vaccine approval.

If that panel recommends emergency use authorization and the CDC director follows with a thumbs up, shots could start as early as the end of next week.

The rates of COVID-19 cases, hospitalizations and deaths are improving; an optimistic sign for the future of the pandemic. But with so many Americans still unvaccinated, the numbers could still go back up, Dr. Anthony Fauci told Fox News Sunday.

"If we don't do very well in that regard, there's always the danger that there will be enough circulating virus that you can have a stalling of the diminishing of the number of cases and when that happens, as we've seen in the past with other waves that we've been through, there's the danger of resurgence," said Fauci, the director of the National Institute of Allergy and Infectious Disease and chief medical adviser to President Joe Biden.

Although cases still remain high at an average of more than 85,000 infections a day, they are down by more than 8,000 from the weeks before, according to data from Johns Hopkins University. And deaths are down an average of more than 200 a day from the start of the month.

Progress in the numbers is still threatened, however, by the low rates of vaccination. As of Sunday, 57% of the total population was fully vaccinated against the virus, according to the Centers for Disease Control and Prevention.

And though health experts do not know exactly what proportion of the population needs to be protected to control the spread of the virus, Fauci has said a vast majority will need to be vaccinated.

The good news is, Fauci does not think another spike in cases is inevitable.

"It's going to be within our capability to prevent that from happening," said Fauci. "The degree to which we continue to come down in that slope will depend on how well we do about getting more people vaccinated."

Johnson & Johnson boosters

As more COVID-19 boosters are potentially set to become available, experts say those who received the Johnson & Johnson one-dose vaccine are "awfully well protected," but should still get another shot for maximum safety.

"The Johnson & Johnson vaccine turns out not to be quite as effective as the Pfizer and Moderna. And people who got (the J&J vaccine) way back at the beginning of this year therefore have been somewhat less protected, although they're still awfully well protected," said Dr. Francis Collins, director of the National Institutes of Health.

Collins' remarks come after a Food and Drug Administration advisory committee recommended all adults who received the single-dose Johnson & Johnson shot should get a second dose at least two months after their first dose.

The FDA will consider the committee's advice. Then the CDC's vaccine advisers will be asked to consider it.

Experts are advising people who received the Johnson & Johnson vaccine should get a booster shot as soon as it is available because it will provide them with the best protection against COVID-19, especially as the more transmissible delta variant continues to be the dominant strain in the United States. But they are also reinforcing the point the vaccine remains highly effective against the worst consequences of the virus.

Johnson & Johnson has indicated its vaccine immunity has waned -- but not by much. Still, the company said studies show a booster dose increases protection equivalent to the 94% efficacy shown by the Moderna and Pfizer mRNA vaccines soon after they were first given in clinical trials last year.

Meanwhile, various real-world studies suggest Johnson & Johnson's vaccine was anywhere between 50% and 68% effective, Dr. Amanda Cohn with the CDC said Friday.

"If the mRNA vaccines from Pfizer and Moderna had not been so utterly, amazingly effective, 95%, then Johnson & Johnson would look like a hero with their one dose, but I guess our standards are being set awfully high here by the other vaccines," Collins told CNN.

But a study published Thursday reported a steep decline in vaccine effectiveness against infection by August of this year, especially for people who received the J&J vaccine.

Researchers found among more than 600,000 veterans, J&J's vaccine's protection against infection fell from 88% in March to 3% in August. Meanwhile, Moderna's vaccine protection against infection fell to 64% from 92%, and Pfizer's declined to 50% from 91% during the same time period.

"The performance of these vaccines against severe disease, keeping people out of the hospital, is distinctly better than that, and that's the main thing we're interested in," said Dr. William Schaffner, a professor in the Division of Infectious Diseases at Vanderbilt University Medical Center in Nashville.

The FDA vaccine advisory committee also supported emergency use authorization for booster shots of Moderna's COVID-19 vaccine after six months, but not for everyone. Moderna recipients over the age of 65 and adults with conditions that put them at risk for severe disease or who work or live in a place which puts them at higher risk of complications or severe illness may be eligible for the 50-microgram booster, which is half the size of the primary two-dose series.

And as for whether booster shots will become available for everyone who's already vaccinated, health officials are still working to determine that.

"I think as more data come in and ... are carefully reviewed and vetted, then I think the expansion of the recommendations may be in order. Not quite yet," Schaffner said.

Minnesota Emergency and Urgent Care services suspended over nurses strike

In many places, the brunt of the hospital strain from COVID-19 has fallen on nurses, and a strike in Minnesota has impacted services.

Emergency and Urgent Care services have been temporarily suspended at Abbott Northwestern WestHealth in Plymouth, Minnesota due to about 50 nurses from the Minnesota Nurses Association (MNA) choosing to strike, according to a statement from Allina Health.

The nurses are striking to seek "a contract that provides fair pay and benefits to nurses on the frontlines of the COVID-19 pandemic," the MNA said in a statement on Thursday.

"MNA nurses have been negotiating a new contract for months, but Allina has refused to agree to fair pay for holiday work or adequate benefits," the MNA said in the statement. "Compensating nurses fairly for holiday work is especially critical because understaffing by Allina and other hospital systems has required nurses to work more days and longer hours, including overtime and holidays, as they continue on the frontlines of the COVID-19 pandemic."

The closure began Sunday morning and will last until 7:00 a.m. local time on Wednesday, according to the statement.

"Allina Health and Abbott Northwestern WestHealth have negotiated 7 times with MNA. A contract settlement was previously reached and unanimously recommended by the union's bargaining team. Unfortunately, the MNA could not finalize that agreement," Allina Health's statement says. "Throughout negotiations, we have consistently offered proposals that demonstrate our commitment to our employees, including an immediate wage increase to align wages with other metro hospitals and agreeing to some of the union's other priority issues."

Black people represent a larger share of new vaccinations

As public health officials talk boosters, 66 million Americans who are eligible for a vaccine still haven't received their initial shots, while nearly 57% of the U.S. population is fully vaccinated, according to the CDC.

Black and brown communities have proven to be disproportionally bearing the brunt of the pandemic for various reasons, including health care inequities.

But there is some good news in terms of Black people's vaccination numbers. Recently, Black people -- who comprise 12.4% of the total U.S. population -- have come to represent a slightly larger share of new vaccinations than in the past, according to the CDC.

Since vaccinations began, Black people in the U.S. have accounted for 10.6% of all people with at least one dose. But in the past two weeks, they have accounted for 11.4% of new vaccinations.

The growth in vaccinations comes after two studies published by the CDC in April showed racial and ethnic minority groups had higher rates of hospitalization for COVID-19 and sought emergency department care for COVID-19 more when compared to White people.

Another analysis published earlier this month by the Kaiser Family Foundation (KFF) showed the difference in COVID-19 cases and deaths between Black, Hispanic and White people is narrowing.

KFF researchers found while disparities are still present across different racial groups, the gap is improving for Black and Hispanic people, based on an analysis of case and death data from CDC last month. But COVID-19 infections remain high in Native American and Alaska Native people.

Some in law enforcement are resisting vaccine, but COVID-19 is killing more of them than gunfire

Meanwhile, COVID-19 has become the leading cause of death for officers, despite law enforcement being among the first groups eligible to receive the vaccine at the end of 2020.

As of Saturday, the total stood at 476 COVID-19 related deaths since the start of the pandemic, compared to 94 from gunfire in the same period.

Still, law enforcement officers and their unions across the country have resisted vaccine mandates, despite the delta variant-fueled resurgence of COVID-19 and effectiveness of the shots in preventing severe cases and death.

Reasons cited for the vaccine resistance among law enforcement officers range from disinformation to distrust in the science of the vaccines.

In Chicago, the head of the police union asked officers not to follow the mayor's order to submit COVID-19 vaccination proof by the Friday deadline.

John Catanzara, the Chicago Fraternal Order of Police president, urged, in a video message posted on YouTube, for officers to stand their ground against the mandate.

"I am telling you right now. It is an improper order. It is illegal ... Refuse that order," Catanzara said in the video.

The city filed a complaint alleging the union was "encouraging a work stoppage or strike." A Cook County Circuit judge ruled Friday night Catanzara should not make public statements encouraging members to not comply with the vaccination policy.

Catanzara "has never engaged in, supported, or encouraged a work stoppage," according to a union statement on Friday.

Lightfoot said the city would take the weekend to check with officers who have not complied with the mandate. She said officers should report for duty until they are told by supervisors they have been placed on leave.

Vaccine advisers to the Food and Drug Administration are meeting Thursday morning to discuss whether to authorize boosters of Moderna's coronavirus vaccine for some adults.

It's the first portion of a two-day Vaccines and Related Biological Products Advisory Committee meeting that will also include a vote on boosters for the Johnson & Johnson vaccine and a presentation on mix-and-match vaccines. Thursday's agenda focuses on Moderna boosters, and includes a presentation by Moderna, and another by the FDA, which will provide its assessment of Moderna's booster data.

Moderna is requesting authorization for a 50-microgram booster dose — half the size of the 100-microgram doses used in the primary series of the two-dose vaccine — at least six months after the second dose, and only for certain groups: people age 65 and older; people ages 18 to 64 who are at high risk of severe COVID-19; and people ages 18 to 64 whose exposure to the coronavirus in their settings or jobs put them at risk for COVID-19 complications or severe illness.

Moderna's request mirrors the groups authorized to receive a booster dose of Pfizer's mRNA vaccine. Third doses of the Moderna and Pfizer COVID-19 vaccines are already authorized for some immunocompromised people.

On Thursday, the committee will hear from Dr. Peter Marks, the director of FDA's Center for Biologics Evaluation and Research who recently took over as acting director of the agency's Office of Vaccines Research and Review as two of its senior leaders prepared to depart the agency.

Israeli researchers will also brief VRBPAC on booster data from there; most people in Israel received the Pfizer COVID-19, and boosters for vaccinated people began weeks before the United States authorized Pfizer boosters. The presenters, Dr. Sharon Alroy-Preiss, director of public health services at Israel's Ministry of Health and Ron Milo, a professor at Israel's Weizmann Institute, spoke in support of Pfizer's booster application last month.

The meeting, which will be streamed online, is scheduled to last until 4:45 p.m. ET. A two-hour period for discussion and voting is scheduled to begin at 2:45 p.m. ET.

The FDA's committee of independent advisers typically discusses and makes recommendations to the agency around vaccine authorizations and approvals, and the agency then makes the final decision about whether to OK a vaccine. If the FDA gives emergency use authorization to Moderna boosters, vaccine advisers to the U.S. Centers for Disease Control and Prevention will meet to discuss which groups to recommend them to. Typically, shots can be administered once the CDC director signs off on the recommendation.

CDC's Advisory Committee on Immunization Practices is already scheduled to meet to discuss boosters from 10 a.m. to 5 p.m. ET Oct. 20-21.

Amid the growing prospect of more COVID-19 booster shots becoming available, an expert has suggested that some people could receive a dose of a different vaccine from the one they initially received.

"I hope that when the FDA and CDC review data around Moderna and Johnson & Johnson that they will allow a mix-and-match approach," CNN Medical Analyst Dr. Leana Wen said Friday.

Vaccine advisers for the U.S. Food and Drug Administration will meet Oct. 14 and 15 to discuss applications for booster doses from Moderna and J&J's vaccine arm Janssen. And on Oct. 20 and 21, vaccine experts with the U.S. Centers for Disease Control and Prevention are slated to discuss the same course of action.

A Pfizer booster shot received emergency use authorization in late September for people 65 and older, people at high risk of severe disease and people whose jobs put them at risk of infection.

Wen, also the former health commissioner for the City of Baltimore, said allowing the mix-and-match option is more convenient to those who initially received the Pfizer or Moderna vaccines in the event either booster shot isn't available where they go for their shot.

"The mRNA vaccines really should be interchangeable," she said.

Pfizer's and Moderna's vaccines both use genetic material called messenger RNA (mRNA) to deliver immunity, but they use differing doses and slightly different formulations. J&J's Janssen vaccine uses an inactivated common cold virus called adenovirus — a viral vector — to carry genetic instructions into the body.

But Wen cautioned that people who received the J&J vaccine may need to consider the risks associated with taking its booster dose.

"We know that there is an association between the Johnson & Johnson vaccine and a very rare — but extremely serious blood clotting disorder — in women under the age of 50," Wen told CNN. She added while she was fully vaccinated with the Johnson & Johnson vaccine, she'd rather get a different vaccine booster.

Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said late last month, "mix and match" studies are underway.

"The mix-and-match study in which you look at Moderna as the boost against the other three, those data are now available," Fauci had said at a White House COVID-19 briefing.

The data has not yet been published or submitted to the FDA.

Already, CDC data shows more than 6 million fully vaccinated Americans have received a booster dose. An average of 390,444 people are getting a booster shot each day, while only 288,105 people are starting their vaccination series each day and 276,539 people are becoming fully vaccinated each day.

Plus, certain people who are immune-compromised can get a third dose, although it's not technically considered a booster because it's likely they did not fully respond to the first two doses.

Overall infections are down, but experts warn against complacency

Still, experts caution that the primary public health focus must remain on getting initial vaccine shots into the arms of the millions of Americans who aren't vaccinated at all.

"As a country, we are definitely trending in the right direction — finally," Wen said. "The problem, though, is that people really need to look at where they are. Because while there are some places that are really doing very well with high vaccination rates and low infection rates, there are also other places that are still trending in the wrong direction."

COVID-19 infections are down by nearly 35% from last month, and the number of people fighting the virus in hospitals dropped by more than 31% from a month earlier, according to data from Johns Hopkins University and U.S. Department of Health and Human Services, respectively.

But experts, including Wen and U.S. Surgeon General Dr. Vivek Murthy, are warning against complacency as there are still areas showing upward trends in deaths and hospitalizations.

"We're thankfully seeing cases and hospitalizations come down, but it's not a reason for us to take our foot off the accelerator or to relax our guards," Murthy said earlier this week.

In Alabama, infections have decreased in recent weeks, but people are still dying from the disease at high rates, a top state health official said Friday.

"Very thankfully, we've had declines in our number of hospitalizations. ... We're down to just over 1,000 in-patients in the state," State Health Officer Dr. Scott Harris said. He acknowledged that the number was still high, "but it's about two-thirds less than we were seeing a month or so ago."

He added: "We have not really seen a change in the number of deaths, unfortunately."

And Pennsylvania reported the highest number of COVID-19 hospitalizations since February, a spokesperson for the state's health department said. Of the 3,001 people hospitalized with the virus, 680 were in intensive care units Thursday, officials said.

COVID-19 racial and ethnic disparity gap narrows but remains wide

Meanwhile, Black and brown communities have been bearing the brunt of the COVID-19 pandemic. Racial and ethnic minority groups had higher rates of hospitalization for COVID-19 and sought emergency department care for COVID-19 more when compared to White people, according to CDC studies published in April.

A new analysis published Friday by the Kaiser Family Foundation (KFF) shows the difference in COVID-19 cases and deaths between Black, Hispanic and White people is narrowing.

KFF researchers found that while disparities are still present across different racial groups, the gap is improving for Black and Hispanic people, based on an analysis of case and death data from CDC last month. But COVIID-19 infections remain high in American Indian and Alaska Native people.

The most recent data included in the report, from Sept. 25, shows a case rate of 96.1 COVID-19 infections for every 100,000 White people. In Hispanic people, this number was 90.8; in Black people, it was 92.7.

The American Indian and Alaska Native communities saw the highest case rate per 100,000 people, at 181. Asian people had the lowest case rate: 42.9 per 100,000 people.

Meanwhile, a report from the CDC on Thursday showed that children from racial and ethnic minorities were far more likely to lose a parent or grandparent who takes care of them.

National Center for Health Statistics data through June showed that children of racial and ethnic minorities accounted for 65% of those who lost a primary caregiver, while White children accounted for 35%. That's even though minorities account for just 39% of the U.S. population.

President Joe Biden will receive his COVID-19 booster shot on Monday, days after federal regulators recommended a third dose of the Pfizer vaccine for Americans age 65 or older and approved them for others with preexisting medical conditions and high-risk work environments.

The White House said Biden, 78, would deliver remarks and receive the additional dose at 1 p.m. Monday.

Biden got his first shot on Dec. 21 and his second dose three weeks later, on Jan. 11, along with his wife, Jill Biden. It was not immediately clear whether the first lady, who's 70, would also receive the booster dose on Monday.

Speaking on Friday after the Centers for Disease Control and Prevention and the Food and Drug Administration authorized the Pfizer booster, Biden told reporters, "I’ll be getting my booster shot. It’s hard to acknowledge I’m over 65, but I’ll be getting my booster shot."

Biden emerged as a champion of booster doses this summer, as the U.S. experienced a sharp rise in coronavirus cases from the more transmissible delta variant. While the vast majority of cases continue to occur among unvaccinated people, regulators pointed to evidence from Israel and early studies in the U.S. showing that protection against so-called breakthrough cases was vastly improved by a third dose of the Pfizer shot.

But the aggressive American push for boosters, before many poorer nations have been able to provide even a modicum of protection for their most vulnerable populations, has drawn the ire of the World Health Organization and some aid groups, which have called on the U.S. to pause third shots to free up supply for the global vaccination effort.

Biden said last week that the U.S. was purchasing another 500 million doses of the Pfizer vaccine — for a total of 1 billion over the coming year — to donate to less well off nations.

Vice President Kamala Harris, 56, received the Moderna vaccine, for which federal regulators have not yet authorized boosters — but they are expected to in the coming weeks. Regulators are also expecting data about the safety and efficacy of a booster for the single-dose Johnson & Johnson shot soon.

CINCINNATI —

The booster roll-out is picking up steam, but many are still unclear about the guidelines determining who is eligible, especially when it comes to defining the “at-risk” occupations.

“For everyone who has a job that puts them at risk, it’s self-attestation. The CDC offers some guidance, but certainly, anyone who feels their job puts them at risk is eligible,” said Hamilton County Health commissioner Greg Kesterman.

The Centers for Disease Control and Prevention guidelines approved by the Ohio Department of Health list certain occupations like healthcare workers, first responders and teachers, but others are left up for interpretation.

“We want people who feel like they need to get vaccinated with the Pfizer vaccine, to have access to it. So, all of our clinics are asking the questions provided by the Ohio Department of Health and we’re providing access,” Kesterman said.

Some of the guidelines from the CDC are more clear than others.

Anyone who wants a booster must have had both shots of the Pfizer vaccine at least six months ago.

Anyone over the age of 65 is eligible. Anyone who is aged 18 to 64 with underlying medical conditions is eligible, among others.

The booster program comes as many employers are enforcing vaccine mandates and vaccine approval for kids ages 5 to 11 is expected by the end of October.

Despite that, Kesterman did not expect any problems with vaccine supply.

CHICAGO — Public health officials have been debating whether it may be more effective to get more people their first dose of the COVID-19 vaccine and delaying the second round of shots that are needed for the highest immunity.

Last month, social media was flooded with images of frontline health care workers proudly rolling up their sleeves to get their first dose of the COVID-19 vaccine.

But a slow rollout, a surge in cases, and the emergence a of a new, more contagious strain of the coronavirus have increased the urgency of the vaccination campaign.

“I think there is an urgency to getting people vaccinated in the best way possible quickly,” said Dr. Benjamin Singer, an assistant professor pulmonary and critical care at Northwestern University’s Feinberg School of Medicine

In the UK, public health officials say prioritizing first doses will delay the interval of the second dose up to 12 weeks.

Pfizer, which is set to deliver 200 million doses of its vaccine to the U.S. by August of 2021, says it has tested their vaccine’s efficacy only when the two doses were administered 21 days apart. Moderna’s two-shot vaccine must be administered 28 days apart.

“Ninety, 95 percent efficacy, I mean, that's an amazing number, but the only way that we know with certainty to get to that level is with that two doses, three to four-week schedule,” said Singer.

Delays in administering the vaccine are already being reported across the U.S. There are now looming questions about what to do if a second dose has to be postponed.

“It could seem premature to begin discussing some of these contingency plans,” said Singer. “But I think it's an appropriate time to at least begin having the discussions.”

According to the Centers for Disease Control and Prevention (CDC), as of Monday morning, of the 15.4 million doses distributed, only 4.6 million people got their first dose.

“Right now, our problem isn't so much having the right number of doses, it's getting those doses into the arms of people,” said Singer.

In recent days, some health experts have suggested delaying the second dose could actually be a strategy to inoculate more people. In a Washington Post op-ed this weekend, Drs. Robert Wachter and Ashish Jha write: “Giving 100 million people — particularly those at high risk — a single shot that is 80 to 90 percent effective will save far more lives than giving 50 million people two shots that are 95 percent effective.”

“There's also some discussion about whether you could stay on the two-shot schedule but give a half dose inject you know half the volume and achieve somewhat of a similar response.”

But late Monday, in a strongly-worded statement, the FDA dismissed the idea of altering dosages and the timeline saying, “…making such changes that are not supported by adequate scientific evidence may ultimately be counterproductive to public health.”

The first doses of the vaccines in the U.S. were administered in mid-December, which means many are due for their booster shot this week.