TAMPA, Fla. - Cases of vaccinated people contracting COVID-19 are not happening as often as it may seem, scientists believe, as 163 million Americans – and about 50% of Floridians – are vaccinated.
Scientists like Dr. Michael Teng, a USF Health virologist, said symptomatic breakthrough infections in people who are already vaccinated are rare even as the delta variant spreads.
"That's a lot of people, so you expect to see some breakthrough infections. The vaccine is not 100%, but it's really close," said Teng. "The other part of it that you have to realize is that when you have when you look at symptomatic infections in the unvaccinated, you're going to see a lot more on a percentage basis. So it's like something like eight times as many."
He explained the chances of a vaccinated person getting sick, compared to an unvaccinated person.
"So if you think about that, you and eight of your friends walk into a room that's just full of SARS-Coronavirus-2. Eight of you are walking out with nothing. One of you might get sick," said Teng. "If you do that with unvaccinated people, you're going to have all of them infected."
On May 1, the Centers for Disease Control and Prevention stopped tracking all symptomatic breakthrough infections, instead, shifting focus to only vaccinated people who end up in hospitals or die.
As of July 26, that number is less than 0.01% out of 163 million fully vaccinated people nationwide who are hospitalized.
"We do still see some breakthrough infections in the hospital, so that is a possibility as well. But not much less than in the unvaccinated population," said Teng.
As for any potential long-term health effects, Dr. Teng said that's an area that has more unknowns.
"Long COVID tends to be an array of symptoms and not everybody has all the same symptoms. So some people have lung problems for a long time. Some people have fatigue for months on end. Some people are on oxygen and some people have neurologic weakness," said Teng. "I think we need to do a much better job of tracking long COVID regardless of vaccination status, and NIH just put in a billion dollars into that."
Scientists said they want to stress that breakthrough infections are rare but expected when the vaccine isn’t 100%. But they said it’s a better way to protect yourself because a breakthrough infection will very likely be milder than if you didn’t have the shot.