Dr. Paul Offit explains why people who were previously infected with SARS-CoV-2 should still get the COVID-19 vaccine.
Should I still get a COVID-19 vaccine if I was previously infected?
Paul Offit, MD: Hi, my name is Paul Offit from the Vaccine Education Center. It's January 2021. One of the questions that we are often asked is: If I've already been infected with the virus, if I've already been infected with SARS-CoV-2, why do I need a vaccine? Presumably I'm just as immune as anybody who's been vaccinated.
So, that's the question. Are you just as immune after you've been naturally infected as someone who's been vaccinated? Well, interestingly, when these companies that made messenger RNA vaccines to prevent SARS-CoV-2 did these trials, what they did was initially, they would give their messenger RNA vaccine and then look to see whether or not that vaccine induced virus-specific neutralizing antibodies, and then compared it to people who'd been naturally infected. And what they found was that as a general rule, those who were vaccinated tended to have a high neutralizing antibody titer as compared to those who were naturally infected, which had a much broader range of neutralizing antibodies. When you were vaccinated, you tended to be in the upper half or upper quartile of that range that was induced by natural infection. Similarly, there was some benefit when the Pfizer trial was done in those who had been naturally infected who got the vaccine as compared to those who were naturally infected who were only been given a placebo, that there was a benefit in those people.
So I think for those reasons, worst case scenario, even if you had a very good immune response after you were naturally infected, you would just simply be boosted by this vaccine. And even better, if you had a relatively low neutralizing antibody response after you were naturally infected, that with the vaccine, you will have an even greater response.
So I think for those reasons, it's certainly a value to be vaccinated even if you've been naturally infected.
Related Centers and Programs: Vaccine Education Center
Last Reviewed on Feb 10, 2021