Antibodies and immunity

One of the big questions for people who had been infected with the coronavirus and recovered is the role of antibodies and immunity. If antibodies are detected in the blood, is a person immune? And if so, for how long? Looking at the larger picture, what would it mean for society’s reopening? And how could those antibodies be put to use -- in the form of convalescent plasma -- to help patients battling a current infection? A new study suggests that if you had been infected, your immunity to the virus could decline within months. The study, which has not yet been peer-reviewed or published, analyzed samples from 65 patients and 31 health care workers. It found that antibody response starts to decline between 20-30 days after someone first experiences Covid-19 symptoms. The study also found the severity of symptoms may be linked to the magnitude of the antibody response. In other words, the sicker you were, the more likely you are to have a more robust antibody response, and therefore longer-lasting immunity. But there’s still so much we don’t know on this topic. More research is needed because the implications are important. For example, a negative antibody test might not mean you didn’t have Covid-19, it might just mean you no longer have the antibodies. Additionally, it raises questions about antibody-based therapies in the works and how quickly someone with confirmed Covid-19 would need to donate plasma for it to be an effective treatment. It also means that any potential vaccine would need to provoke a really strong antibody response in order to create lasting protection.