Related video above: Pfizer vaccine trial begins with young children

The Pfizer COVID-19 vaccine has been found to be 100% effective in adolescents, who showed “very high antibody” responses, exceeding the antibody responses in vaccinated adults, the company announced Wednesday.

In study participants aged 12 to 15 years old with or without prior evidence of COVID-19 infection, the vaccine demonstrated 100% real efficacy, Pfizer said.

“We share the urgency to expand the use of our vaccine to additional populations and are encouraged by the clinical trial data from adolescents between the ages of 12 and 15,” said Albert Bourla, chairman and chief executive officer of Pfizer.

Pfizer plans to submit the data to the U.S. Food and Drug Administration in the coming weeks for a requested amendment to the vaccine’s emergency use authorization, with the hope of starting to vaccinate the age group before the start of the next school year.

The trial enrolled 2,260 adolescents 12 to 15 years of age. In the trial, 18 cases of COVID-19 were observed in the placebo group versus none in the vaccinated group.

It's a small study, that hasn't yet been published, so another important piece of evidence is how well the shots revved up the kids’ immune systems. Researchers reported high levels of virus-fighting antibodies, somewhat higher than were seen in studies of young adults.

Kids had side effects similar to young adults, the company said. The main side effects are pain, fever, chills and fatigue, particularly after the second dose. The study will continue to track participants for two years for more information about long-term protection and safety.

Pfizer and its German partner BioNTech in the coming weeks plan to ask the U.S. Food and Drug Administration and European regulators to allow emergency use of the shots starting at age 12.

In the company statement, Bourla also expressed “the hope of starting to vaccinate this age group before the start of the next school year" in the United States.

All participants in the trial will continue to be monitored for long-term protection and safety for an additional two years after their second dose.

Last week, the company dosed the first healthy children in the study to evaluate the safety and effectiveness of the vaccine in children 6 months to 11 years old.

Pfizer isn’t the only company seeking to lower the age limit for its vaccine. Results also are expected soon from a U.S. study of Moderna’s vaccine in 12- to 17-year-olds.

But in a sign that the findings were promising, the FDA already allowed both companies to begin U.S. studies in children 11 and younger, working their way to as young as 6-month-old.

AstraZeneca last month began a study of its vaccine among 6- to 17-year-olds in Britain. Johnson & Johnson is planning its own pediatric studies. And in China, Sinovac recently announced it has submitted preliminary data to Chinese regulators showing its vaccine is safe in children as young as 3.

While most COVID-19 vaccines being used globally were first tested in tens of thousands of adults, pediatric studies won’t need to be nearly as large. Scientists have safety information from those studies and from subsequent vaccinations in millions more adults.

One key question is the dosage: Pfizer gave the 12-and-older participants the same dose adults receive, while testing different doses in younger children.

It's not clear how quickly the FDA would act on Pfizer's request to allow vaccination starting at age 12. Another question is when the country would have enough supply of shots — and people to get them into adolescents' arms — to let kids start getting in line.

Supplies are set to steadily increase over the spring and summer, at the same time states are opening vaccinations to younger, healthier adults who until now haven't had a turn.

Children represent about 13% of COVID-19 cases documented in the U.S. And while children are far less likely than adults to get seriously ill, at least 268 have died from COVID-19 in the U.S. alone and more than 13,500 have been hospitalized, according to a tally by the American Academy of Pediatrics. That’s more than die from the flu in an average year. Additionally, a small number have developed a serious inflammatory condition linked to the coronavirus.

Caleb Chung, who turns 13 later this week, agreed to volunteer after his father, a Duke University pediatrician, presented the option. He doesn't know if he received the vaccine or a placebo.

“Usually I’m just at home doing online school and there’s not much I can really do to fight back against the virus,” Caleb said in a recent interview. The study “was really somewhere that I could actually help out.”

His father, Dr. Richard Chung, said he’s proud of his son and all the other children volunteering for the needle pricks, blood tests and other tasks a study entails.

“We need kids to do these trials so that kids can get protected. Adults can’t do that for them,” Chung said.

The Associated Press contributed to this report.

HINSDALE, IL — Remote learning has transformed how schools handle sex education.

During the pandemic, students spent more time online, further isolated from social, emotional, and mental health. But experts say the internet should not be the source of sexual education for kids, and the current health crisis has complicated the issue.

When it comes to sex education, like most parents, Laura Burns doesn’t want her 5^th grader clicking around on the internet.

“Unfortunately, when it comes to sex ed and things that they might be really curious about, there's way more misinformation than good and true information, in my opinion,” said Burns.

Her 11-year-old daughter, Katie, is now at an age when children start to become curious.

“If I feel uncomfortable, I might think about it, but I mostly still go to my mom,” said Katie Burns said.

“I also realize that she's getting to the point where it may become uncomfortable to ask me something,” said Laura Burns.

According to one study conducted at the outset of the COVID outbreak, half of 11 to 13-year-olds reported having seen pornography in some way. Nearly two-thirds of them said they had done so to learn about sex generally.

“The average age of first exposure to some sort of online pornography is 9,” said Katie Gallagher, director of education for Candor Health Education.

Originally a health museum for more than half a century, the nonprofit Candor Health Education has taught health, sex education, and drug prevention to students from 4^th to 8^th grade.

Gallagher points out with social isolation and increased time spent online, the pandemic has only compounded the issue.

“Kids are going to see this now. We have to make sure that we they know what to do when they do, and they have the right places to go and the right information,” said Gallagher.

Over the last few years, the nonprofit's outreach programming has had to shift, accelerated by remote schooling.

“We saw that it was not going to be a possibility this year, and we spent all of last summer really reworking our programs so that we could offer various virtual delivery models,” said Gallagher.

Katie Burns recently went through the new learning system with her mom at her side.

“I thought it was going to make it a bit uncomfortable and impersonal,” said Laura Burns. “And I actually found it to be the exact opposite.”

“They went deeper, and I understood things differently and more clearly,” said daughter Katie.

And while experts say sexual education should not come from the internet, the future of its delivery will likely end up becoming more virtual and online.