Why are some people testing positive for COVID-19 after taking a COVID-19 vaccine?
Why are some people testing positive for COVID-19 after taking a COVID-19 vaccine?
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There are a few main reasons why someone may test positive for COVID-19 after taking a COVID-19 vaccine. 1. The vaccines that are currently most widely distributed—the Moderna vaccine and the Pfizer-BioNTech vaccine—are reported to have about 95% efficacy. This means that about 5% of vaccinated people are still likely to contract COVID-19. As a result, some individuals are testing positive for COVID-19 despite having gotten a vaccine. The chance of hospitalization or death in a vaccinated COVID-19 patient is significantly lower than an unvaccinated COVID-19 patient. 2. After someone gets the shot, it takes time to build up immunity to COVID-19. The full benefits of the vaccines aren't reached until two weeks after the second dose of the Moderna vaccine and 7 days after the second dose of the Pfizer-BioNTech vaccine. In the time leading up to maximum immunity, the chances of contracting COVID-19 are not zero. 3. COVID-19 vaccine efficacy rates published by pharmaceutical companies do not yet tell us the exact vaccine effectiveness rates that can be expected in actual populations. As a result, it is possible that the number of individuals (5%) who are estimated to still contract COVID-19 despite being vaccinated could actually be different in the population. No vaccine is perfect, and there are a range of factors that contribute to chances of the vaccine not working, such as weakened immunity and viral load exposure. It is highly unlikely that false positives are contributing to the numbers of vaccinated individuals testing positive, given that neither the Moderna nor the Pfizer-BioNTech vaccine cause you to test positive on a viral test. Public health professionals advise wearing a mask and maintaining physical distance even after getting vaccinated, in order to protect those that are not vaccinated as yet and to stop further spread in the community.
There are a few main reasons why someone may test positive for COVID-19 after taking a COVID-19 vaccine. 1. The vaccines that are currently most widely distributed—the Moderna vaccine and the Pfizer-BioNTech vaccine—are reported to have about 95% efficacy. This means that about 5% of vaccinated people are still likely to contract COVID-19. As a result, some individuals are testing positive for COVID-19 despite having gotten a vaccine. The chance of hospitalization or death in a vaccinated COVID-19 patient is significantly lower than an unvaccinated COVID-19 patient. 2. After someone gets the shot, it takes time to build up immunity to COVID-19. The full benefits of the vaccines aren't reached until two weeks after the second dose of the Moderna vaccine and 7 days after the second dose of the Pfizer-BioNTech vaccine. In the time leading up to maximum immunity, the chances of contracting COVID-19 are not zero. 3. COVID-19 vaccine efficacy rates published by pharmaceutical companies do not yet tell us the exact vaccine effectiveness rates that can be expected in actual populations. As a result, it is possible that the number of individuals (5%) who are estimated to still contract COVID-19 despite being vaccinated could actually be different in the population. No vaccine is perfect, and there are a range of factors that contribute to chances of the vaccine not working, such as weakened immunity and viral load exposure. It is highly unlikely that false positives are contributing to the numbers of vaccinated individuals testing positive, given that neither the Moderna nor the Pfizer-BioNTech vaccine cause you to test positive on a viral test. Public health professionals advise wearing a mask and maintaining physical distance even after getting vaccinated, in order to protect those that are not vaccinated as yet and to stop further spread in the community.
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What our experts say
There are a few main reasons why someone may test positive for COVID-19 after taking a COVID-19 vaccine.
- The vaccines that are currently most widely distributed—the Moderna vaccine and the Pfizer-BioNTech vaccine—are reported to have about 95% efficacy. This means that about 5% of vaccinated people are still likely to contract COVID-19. As a result, some individuals are testing positive for COVID-19 despite having gotten a vaccine. The chance of hospitalization or death in a vaccinated COVID-19 patient is significantly lower than an unvaccinated COVID-19 patient.
- After someone gets the shot, it takes time to build up immunity to COVID-19. The full benefits of the vaccines aren't reached until two weeks after the second dose of the Moderna vaccine and 7 days after the second dose of the Pfizer-BioNTech vaccine. In the time leading up to maximum immunity, the chances of contracting COVID-19 are not zero.
- COVID-19 vaccine efficacy rates published by pharmaceutical companies do not yet tell us the exact vaccine effectiveness rates that can be expected in actual populations. As a result, it is possible that the number of individuals (5%) who are estimated to still contract COVID-19 despite being vaccinated could actually be different in the population. No vaccine is perfect, and there are a range of factors that contribute to chances of the vaccine not working, such as weakened immunity and viral load exposure.
It is highly unlikely that false positives are contributing to the numbers of vaccinated individuals testing positive, given that neither the Moderna nor the Pfizer-BioNTech vaccine cause you to test positive on a viral test.
Public health professionals advise wearing a mask and maintaining physical distance even after getting vaccinated, in order to protect those that are not vaccinated as yet and to stop further spread in the community.
There are a few main reasons why someone may test positive for COVID-19 after taking a COVID-19 vaccine.
- The vaccines that are currently most widely distributed—the Moderna vaccine and the Pfizer-BioNTech vaccine—are reported to have about 95% efficacy. This means that about 5% of vaccinated people are still likely to contract COVID-19. As a result, some individuals are testing positive for COVID-19 despite having gotten a vaccine. The chance of hospitalization or death in a vaccinated COVID-19 patient is significantly lower than an unvaccinated COVID-19 patient.
- After someone gets the shot, it takes time to build up immunity to COVID-19. The full benefits of the vaccines aren't reached until two weeks after the second dose of the Moderna vaccine and 7 days after the second dose of the Pfizer-BioNTech vaccine. In the time leading up to maximum immunity, the chances of contracting COVID-19 are not zero.
- COVID-19 vaccine efficacy rates published by pharmaceutical companies do not yet tell us the exact vaccine effectiveness rates that can be expected in actual populations. As a result, it is possible that the number of individuals (5%) who are estimated to still contract COVID-19 despite being vaccinated could actually be different in the population. No vaccine is perfect, and there are a range of factors that contribute to chances of the vaccine not working, such as weakened immunity and viral load exposure.
It is highly unlikely that false positives are contributing to the numbers of vaccinated individuals testing positive, given that neither the Moderna nor the Pfizer-BioNTech vaccine cause you to test positive on a viral test.
Public health professionals advise wearing a mask and maintaining physical distance even after getting vaccinated, in order to protect those that are not vaccinated as yet and to stop further spread in the community.
Context and background
As more individuals receive the vaccine, more cases are emerging of vaccinated individuals are testing positive. With these cases, questions have been arising regarding why vaccination doesn’t protect someone entirely, and if vaccination could cause someone to test positive.
As more individuals receive the vaccine, more cases are emerging of vaccinated individuals are testing positive. With these cases, questions have been arising regarding why vaccination doesn’t protect someone entirely, and if vaccination could cause someone to test positive.
Resources
- COVID-19 Vaccine FAQs for Healthcare Professionals (CDC)
- Myths and Facts about COVID-19 Vaccines (CDC)
- Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine (NEJM)
- Overview of Vaccine Efficacy and Vaccine Effectiveness (WHO)
- Vaccine Efficacy, Effectiveness and Impact (KCE)
- COVID-19 Vaccine: What You Need to Know (Johns Hopkins)
- Facts about COVID-19 Vaccines (US C.D.C.)
- Here’s Why Vaccinated People Still Need to Wear a Mask (NYT) Could people still be infectious after they’re vaccinated for COVID-19? (CBS News)
- Vaccinated but Sick With COVID-19 (Medpage Today)
- COVID-19 Vaccine FAQs for Healthcare Professionals (CDC)
- Myths and Facts about COVID-19 Vaccines (CDC)
- Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine (NEJM)
- Overview of Vaccine Efficacy and Vaccine Effectiveness (WHO)
- Vaccine Efficacy, Effectiveness and Impact (KCE)
- COVID-19 Vaccine: What You Need to Know (Johns Hopkins)
- Facts about COVID-19 Vaccines (US C.D.C.)
- Here’s Why Vaccinated People Still Need to Wear a Mask (NYT) Could people still be infectious after they’re vaccinated for COVID-19? (CBS News)
- Vaccinated but Sick With COVID-19 (Medpage Today)
