“SARS-CoV-2 is getting all these strange mutations. Should I be worried that the vaccine may not work?”
The simple answer: most likely not! Here is how it works:
- All of us might have had seasonal flu from any of the common coronaviruses (OC43, 229E, NL63, and HKU1) in our lifetime. These are all RNA viruses. Similarly, SARS-CoV-2 is an RNA virus, and we know that all RNA viruses evolve rapidly during multiple cycles of replication. That’s why we get seasonal flu from various respiratory viral variants at least once every 3 years.
- During this process, some RNA viruses are able to accept mutations to their surface proteins in such a way that they may partially escape human immunity. This process is known as “antigenic drift.” The Beta-Coronavirus genus has this antigenic drift capability.
- Though there are many, we know about following considerable antigenic variants of SARS-CoV-2 based on spike protein variation: N439K, N501Y, S477N, Y453F, D80Y, etc.
- Now, certain genetic variants may spread more than others based on natural selection and partial local immunity to a previously infecting variant. So, continue to use face masks and practice hand hygiene.
- The good news is that most of these variants have only a single mutation, and most of these don’t affect the spike receptor-binding domain. Such single mutations will generally have fewer impacts on the polyclonal strong immune response that we develop due to the mRNA vaccines. Hence, get the vaccine.
What scientists will do? Based on new genetic variants, mRNA vaccines can be appropriately updated quickly, keeping in view the seasonal prevalence and antigenic drift. This is not new and is already in practice with influenza vaccine development.
What don’t we know yet? So far, we are pretty early in vaccine studies, and it will take at least a couple years to confidently answer the question of how frequently we need to get a COVID-19 vaccine to prevent infection from lethal genetic variations.