Those numbers come with caveats, mainly because vaccines have been available to most Americans only for about six months. Scientists still are studying their effectiveness, their ability to stand up to variants and the duration of the protection they provide.
But those same scientists say the early returns are excellent. They also say Americans shouldn’t be discouraged when they hear that vaccinated people are testing positive for the virus, as thousands have during the latest surge in cases.
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That’s because the purpose of the vaccines isn’t to prevent people from catching the virus. It’s to prevent them from becoming seriously ill or dying because of the virus.
“I think some people thought, ‘I got the vaccine. I’m bulletproof,’ ” said Dr. Carl Fichtenbaum, a professor of infectious disease at the University of Cincinnati and medical director of UC Health’s Phase 3 Moderna vaccine trial.
“That’s not how vaccines are designed,” he said. “The vaccine is working very well.”
A different population is getting sick
The most recent wave of coronavirus cases – the national seven-day rolling average now stands at about 140,000 cases a day – is the worst since the peak of the pandemic last winter. It’s a tragedy, but it also has been instructive to scientists studying the effectiveness of vaccines.
Feagins said he can see it every day in the hospital. Last year, his most seriously ill patients were almost all over 60 years old. Today, he said, about 40% are under 60.
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He said the difference is the vaccines. The CDC estimates the best vaccines are up to 90% effective at fighting off serious illness, and the older population is more likely than any other to get vaccinated.
So even though elderly people are more vulnerable to the virus, they are getting sick less often than they did before. Younger patients, meanwhile, are less likely to be vaccinated and are now easier targets for the virus.
“It’s a very different population that’s being hospitalized now,” Feagins said. “They’re unvaccinated.”
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He said one of the best case studies on vaccine effectiveness is going on right now in Iceland, which is enduring its highest level of infections since the start of the pandemic despite one of the highest vaccination rates in the world.
While vaccine opponents have said Iceland’s experience proves the vaccines are ineffective, scientists say it proves the opposite. According to the Washington Post, 2% of Iceland’s infected population has been hospitalized and no deaths have been reported since May.
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In other words, scientists say, the vaccines are doing their job.
“They have lots of positive tests, but they’re not getting sick from it,” Feagins said.
Though the numbers so far have been low, there are exceptions. People with underlying health conditions, the elderly and those with compromised immune systems all are at a higher risk of illness, even if they are vaccinated.
And some people, Fichtenbaum said, just don’t respond to the vaccines the way most do. For that reason, he said, it’s important for everyone, including vaccinated people, to understand how the vaccines work.
Rather than creating an impenetrable shield over a person’s body, vaccines train the immune system to recognize and attack the virus. Fichtenbaum compared the COVID-19 vaccines to the first polio vaccines, which did not prevent people from catching the polio virus.
Instead, he said, the vaccines limited the spread of the virus within a person’s body and reduced that person’s ability to shed the virus and infect others. The vaccines didn’t stop infections. They stopped the disease.
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The same is true with the coronavirus, Fichtenbaum said. People can still catch the virus but are much less likely to develop COVID-19, the disease caused by the virus, if they’re vaccinated. They also are less likely to spread the virus, though how much less isn’t entirely clear.
“Vaccination is the single most effective way to not just protect yourself, but your family and your community,” said Christa Hyson, spokeswoman for the Health Collaborative.
The governors of Ohio, Kentucky and Indiana all have made the same point in recent weeks as case numbers continue to rise.
“We know what works,” Indiana Gov. Eric Holcomb said Wednesday. “And that’s the vaccines.”
Delta variant spreads among everyone
There still is risk, however, even for those who heed that advice and get vaccinated.
Scientists say the coronavirus is thriving today primarily for two reasons: The relaxing of safety measures, such as masks and social distancing, and the arrival of the delta variant.
The delta variant is at least two to three times more transmissible than earlier strains of the virus, which means the dominant strain in the United States today is about as contagious as chickenpox.
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Feagins said that means this strain of the virus is exponentially more dangerous than its predecessor because every person who catches it is spreading it two to three times more easily.
Feagins compared it to the way the Richter scale measures earthquakes: An increase from 5 to 6 isn’t linear, it’s logarithmic, which means each step up represents about a thirtyfold increase in severity.
So even with half the population vaccinated and at least some level of immunity among people who were previously infected, the virus can spread like the proverbial wildfire. Which is what’s happening today.
Fichtenbaum said that’s why it’s a mistake to stop wearing masks and taking other common-sense precautions, like regularly washing hands and avoiding crowded places, especially indoors.
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The vaccines are working, he said, but the virus is working, too. And since vaccinated people are less likely to get sick and, in many cases, less likely to even know they’re sick, it makes sense to be careful to protect people around them.
Not doing so, Fichtenbaum said, is like recklessly driving a car without knowing how many people you hit along the way.
“People who become infected,” he said, “don’t have the benefit of seeing where their infection goes.”
