Can I catch COVID twice? What happened to herd immunity?
Two major studies published within the last week bring the hope of eventual herd immunity into serious question. The first, published in The Lancet July 6th, suggested that too many lives would be lost while waiting to achieve the approximate 60% infection rate needed to provide herd immunity (which describes when so many people have had, and are immune to, an infection that it is effectively stamped out). The second, published online by King’s College London July 9th, showed that antibody levels to the virus may not last very long at all, allowing for reinfection even within the same year. Antibody levels peak sharply after two weeks, but then decline, generally disappearing entirely somewhere between four months and one year. This quickly waning immunity is consistent with our understanding of the four coronavirus OG’s, the “traditional” four members of the coronavirus family for which we have 60 years of research, and which generally only cause colds. They can come back year after year, and reinfect the same people. Even without mutating from year to year like influenza viruses.
This means that naturally occurring herd immunity may never be achievable. This is not cause for dismay but rather a call to action; it will be by our hand that we stop the spread of this disease. And while we wait for a medical solution, government action and strong national leadership has been proven to work to control outbreaks. But every one of us has a role to play: wearing a mask, practicing safe physical distancing, and choosing the inconvenience of self-isolation when we fear we’ve been exposed to infection.
“We’re Wasting Time Talking About Herd Immunity”
Opinion by William Haseltine on cnn.com
Sky Pittson, MD, July 13, 2020