Antibodies and your immunity

There’s evidence that people might start to lose immunity to the novel coronavirus within a few weeks after they have been infected -- especially if they have mild symptoms or no symptoms. A team at the University of California Los Angeles studied 34 people who recovered from mild coronavirus infections. They tested their blood two or three times over three months. They found a rapid drop in antibodies -- the immune system proteins that help stop viruses from infecting cells in the body. On average, the antibody levels fell by half every 36 days, the team reported in The New England Journal of Medicine. A survey of people in Spain published earlier this month found similar results. But it's important to put this in context. Does that mean you're also losing immunity? We are almost six months into the pandemic in the United States and we have not really seen reinfection clusters. If you did lose immunity within a few weeks, we would expect to see more reports of reinfections, not just anecdotes here and there. So it's important to remember that while this sounds alarming, the antibodies are not the only thing to tell us about immunity. One, for example, is T-cells, which are harder to measure and study. They are at the core of the immune system and can quickly ramp up antibody production in response to a virus. They can attack the virus in other ways as well. We’re just starting to scratch the surface of understanding many aspects of this virus, and pinning down immunity is one we need to dig deeper on.