A few weeks ago, a message popped up in the corner of my screen. “What do you think about people who have recently had Covid–19 getting the vaccine?” A friend of mine was eligible for a Covid–19 vaccine, but she had recently gotten over an infection with SARS–CoV–2. More people are becoming eligible for vaccines each week – including millions of people who have already recovered from a coronavirus infection. Many are wondering whether they need the vaccine, especially people who have already been infected.
I study immune responses to respiratory infections, so I get a lot of these types of questions. A person can develop immunity – the ability to resist infection – from being infected with a virus or from getting a vaccine.
However, immune protection is not always equal. The strength of the immune response, the length of time that the protection lasts and the variation of the immune response across people is very different between vaccine immunity and…