Question: If there is a vaccine developed against Covid-19, would it also prevent against future mutations?

Alex Holmes answered on 11 Jun 2020:

Hi David, this is a really good question.

So the main thing that would determine this is how different the mutations make the virus. A vaccine works by showing our immune system a part of the virus so that it can make antibodies that will recognise it if we got infected later. One of the common virus parts that is being used currently is the spike protein (which is that bit that sticks out you see in pictures and how the virus gets into cells). The way antibodies would recognise the spike protein is through their shape – a bit like puzzle pieces they fit together!

Now a mutation is where there is a change in the genetics of the virus (in this case it’s RNA not DNA), this change in the genetics will then change the proteins the virus makes. This change could affect how it works or its shape… which is what the antibodies are using to recognise it. Coronaviruses have more proteins than just the spike protein, so the mutations might not happen to the spike. Or it might happen in a different part of the spike to where the antibodies work. If it did happen where the antibodies fit this could cause the antibody to no longer fit and no longer be able to recognise the mutated virus – meaning the vaccine wouldn’t be protective anymore.

However, like I said the mutations can also affect how the protein works, and it’s really important the spike protein is the right shape so it can do it’s job getting into cells. So it might be that the spike can’t mutate very much without making the virus ineffective, which adds some protection to the vaccine continuing to work!

I hope that answers your question.