"Breakthrough” is the new pandemic buzzword. Reports of Americans testing positive for COVID-19 despite being fully vaccinated have been making headlines lately — from the halls of Congress to Yankee Stadium to summer celebrations at the tip of Cape Cod. But are these cases, which seem to be popping up more frequently, cause for concern?
Here's what the experts have to say about breakthrough infections.
1. Breakthrough cases are normal
No vaccine is 100 percent effective at preventing disease. But the shots authorized in the U.S. to help quell COVID-19 are pretty close — especially when it comes to thwarting severe illness and death, which is what they were designed to do.
In fact, less than 1 percent (about 0.004 percent) of fully vaccinated individuals have been hospitalized with, or have died from, COVID-19, according to the latest data tracked by the Centers for Disease Control and Prevention (CDC). When it comes to older adults, who were hit hardest by the coronavirus during its initial sweep, fully vaccinated individuals ages 65 and up are 94 percent less likely to be hospitalized with COVID-19 than people of the same age who are not vaccinated.
And while the CDC no longer tracks how many vaccinated individuals come down with an asymptomatic or mild case of COVID-19 — the more likely scenario if you do get a breakthrough infection — it's safe to assume the risk is also on the smaller side, explains Christopher Ohl, M.D., professor of infectious diseases at the Wake Forest School of Medicine. “It's not common, but it happens,” he says. (New data analyzed by the Kaiser Family Foundation confirms this.)
The important thing to keep in mind is that when these cases occur, “by no means does that mean that you're dealing with an unsuccessful vaccine,” Anthony Fauci, M.D., director of the National Institute of Allergy and Infectious Diseases, said in a recent press briefing. “The success of the vaccine is based on the prevention of [more serious] illness.”
2. Delta variant is partially to blame
Breakthrough infections could become more prevalent, however, as the highly contagious delta variant continues to blaze through unvaccinated communities. (About half of the country is not fully vaccinated.)
That's not because the vaccines don't work against the now-dominant strain, which is responsible for more than 80 percent of new COVID-19 cases in the U.S. Studies show that while the immune response is somewhat diminished against delta compared to other virus variants, the vaccines are still holding their ground when a full dose regimen is completed. Rather, it has to do with frequency of exposure.
"Think of the vaccine as reducing your risk of getting infected in any given encounter by something like 90 percent,” says David Dowdy, M.D., associate professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health. If you're in a situation where there are more cases of COVID-19 and you're having closer interactions with people, “then we expect more breakthrough infections — not because the vaccines aren't working but just because people are being exposed [to the virus] more often,” he adds.
Leana Wen, M.D., an emergency physician and visiting professor of health policy and management at George Washington University's Milken Institute School of Public Health, has likened the vaccines to a very good raincoat. “If it's drizzling outside, you're going to be fine; you will be protected and not get wet. However, if you keep going in and out of thunderstorms, at some point you could get wet,” she told AARP in a recent interview.