One of the arguments against the COVID-19 vaccine mandates is that immunity from a previous coronavirus infection should count as an alternative to vaccination. This topic has received a lot of attention of late, with NBA players and health care workers speaking out and citing “natural immunity” as what they believe to be a valid reason for refusing to get the shot.
However, health experts in the U.S. say immunity through vaccination is the best way to protect people who have had COVID-19 from reinfection. Dr. Peter Hotez, co-director of the Center for Vaccine Development at Texas Children’s Hospital, explains why.
PETER HOTEZ: First, the Centers for Disease Control in their "MMWR" published a very interesting study out of Kentucky comparing individuals who were infected and recovered and chose not to get vaccinated versus those who are infected and recovered and then got vaccinated in addition. And clearly, those who chose not to get vaccinated were reinfected at much higher rates, several times higher, than those who were infected and recovered and vaccinated. So the bottom line is if you're infected and recovered, you're still susceptible to reinfection.
The other disadvantage, even if you're infected, is whether or not you're going to be resistant to reinfection. Because if you look at some of those early studies that were done, people who are infected and recovered have highly variable heterogeneous responses to the virus, some pretty strong vigorous responses, others have almost no virus neutralizing antibody or responses at all and are highly susceptible to reinfection. And you never know which way you're going to wind up.
The mechanism by which you get the added protection from vaccination was shown very nicely in a paper by Michel Nussenzweig's group at Rockefeller University in New York back in June, where they showed that people who were infected and recovered and then vaccinated not only have very high levels of virus neutralizing antibodies and T and B cell responses, but in addition, they exhibit something called epitope broadening, where they're extremely resilient against variants. So no question if you're infected and recovered, you want to get vaccinated.
I mean, we do have tests to measure antibody. In theory, you could even measure virus neutralizing antibody in a specialty lab, but that's not easy to do in a high throughput way. You can measure T cell responses and B cell responses. The problem is this-- we do not have what we call a true correlative protection. We do not have a blood test, or even a series of blood tests, that we can say definitively, you know, thumbs up, thumbs down, you're protected or not. You just don't know.
The problem is Delta is such a game changer. If you get infection and you're not vaccinated, you're at high risk of hospitalization and death, especially with the Delta variant. And that's what we're seeing 2,000 Americans die every day, the vast majority are unvaccinated. So for all those reasons, if you've not been vaccinated, get vaccinated. If you've been infected and recovered, get vaccinated.