How likely is it that fully vaccinated people could be infected/reinfected with COVID-19?
How likely is it that fully vaccinated people could be infected/reinfected with COVID-19?
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SciLine reaches out to our network of scientific experts and poses commonly asked questions about newsworthy topics. Reporters can use these responses in news stories, with attribution to the expert.
SciLine reaches out to our network of scientific experts and poses commonly asked questions about newsworthy topics. Reporters can use these responses in news stories, with attribution to the expert.
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Expert Comments:
Ashish K. Jha, PhD
The data from both clinical trials and large ‘real world’ studies have shown that the coronavirus vaccines in use in the United States are very protective against COVID-19. Someone who has been fully vaccinated—meaning two weeks following their last shot—is unlikely to become infected if exposed to the virus and, even if they do get infected, is much less likely to experience severe symptoms, and extremely unlikely to be hospitalized. We don’t know exactly how long vaccine immunity lasts, but we do know it lasts at least six months to a year, and it could last several years.
The vaccines are also effective against the viral variants currently prevalent in the United States. It is possible that the virus will mutate in such a way that the vaccines are less effective, in which case Americans may need to get booster shots to ensure adequate protection.
Rachael Lee, MD, MSPH
No vaccine is 100% effective and vaccine breakthrough cases are expected. Recent data published from the CDC has shown 7,157 cases of breakthrough infections out of more than 87 million people fully vaccinated. Of these, very few were hospitalized and even a smaller portion died (<1%). Recent evidence has shown that out of nearly 4,000 healthcare personnel and first responders, those who were fully vaccinated were 90% less likely to get infected. These data and others coming out show how important the vaccine is in preventing severe illness from COVID-19.
