If we are ever to return to some semblance of normality, then the world’s population needs to be immune to SARS-CoV-2, the virus that causes COVID-19. But with so many different vaccines in production, questions are undoubtedly going to be raised, such as can I still have a vaccine if I have been involved in a trial testing other versions? And, what if I’ve already had COVID – do I still need a vaccine?
A basic understanding of immunology can answer all these questions. All COVID vaccines try to generate an immune response to proteins the virus needs to enter your cells. Whether this is by using a harmless virus carrying the protein that mimics SARS-CoV-2 but doesn’t replicate, or by using the genetic code for those proteins (a messenger RNA), the outcome is the same. The protein critical to stopping SARS-CoV-2 is displayed, recognised by the immune system, and the body produces antibodies and T cells that are then ready to stop future infection.