“COVID breakthrough” cases occur when people who are fully vaccinated test positive for COVID. In other words, they are infected with COVID in their nose and/or throat. It may also be in their bloodstream, yet they may have light symptoms of COVID or perhaps be totally asymptomatic, i.e., have no symptoms at all.
So, do COVID “breakthroughs” mean the vaccine isn’t working? They don’t mean that at all. Vaccines are not intended to keep a person from becoming infected. They are intended to keep an infected person from becoming sick, or being hospitalized, or dying.
As the University of North Carolina (UNC) online publication “Health Talk” explains at www.healthtalk.unchealthcare.org/COVID-19-breakthrough-infec
tions-3-things-to-know/, the term “breakthrough” is a misleading misnomer. “In the case of COVID-19, the vaccines do not prevent the virus from getting into your nose or throat, but they do make sure the immune system can protect you from getting sick.”
“Vaccines are not a force field that protects you from the virus coming into your body,” said David A. Wohl, M.D., an infectious diseases specialist at UNC Health. “The virus can find its way into your nose like we have seen in some of these baseball players or Olympians, but if you are vaccinated, it is unlikely to make you very sick.”
Vaccines clearly do a good job of that. The Centers for Disease Control and Prevention (CDC) reports that, currently throughout the United States, roughly 97% of new COVID hospitalizations and 99.5% of new COVID deaths occur in unvaccinated persons.
And this is also why we all should still be wearing masks, whether we’re vaccinated or not. The virus can be heavily loaded in the nose and throat of fully vaccinated persons, even if they have zero symptoms of COVID. So fully vaccinated people can still unknowingly pass on the virus to other persons who are vaccinated or not. This is especially true of the currently prevalent Delta variant of the virus, which is many times more transmissible than earlier variants.
“The delta variant leads to a lot more virus being present in people’s upper respiratory system — even those who are vaccinated. But they may not know it,” Wohl says. “This is why masking is really important now, during this surge. Since the vaccinated are really unlikely to become sick if they catch the COVID-19 virus, they can still pass it on unwittingly.”