Should you take the Covid vaccine if you have already had Covid?
The latest word (an extremely well-made scientific study here in Sweden) says that you have a better than 95% immunity for at least 9 months after infection. This is quite on par with the best vaccines. They looked at S antibodies (against the spike protein), in contrast with other studies that have primarily looked at N antibodies (against the “nucleus” of the virus)—N antibodies tend to fade after 3–4 months, but the S antibodies lasted longer, and that’s the antibodies that the vaccines will coax the body into producing, so the results are directly comparable. In addition, you have a Covid-19-specific T cell response after going through the infection.
The conclusion from that study was that yes, if you have gone through a Covid-19 infection you should still get vaccinated as a booster, but there’s no rush. You are protected to some extent, and even if you do get re-infected, you are less likely to spread the virus.
Meanwhile, a French study indicates that it’s possible that one shot is enough for boosting the immune response after Covid-19 infection.