As the COVID-19 virus mutates, will the vaccine still be effective?

There is evidence that the COVID-19 virus is constantly mutating, There are an estimated 25 mutations separating today's virus from the one that surfaced in Wuhan, China, a year ago. That's no surprise; that's what viruses do.

In Britain, for example, there are two main new mutated strains (mutation 501, and a H69/V70 deletion), largely affecting the densely-populated southeast of the country. Both of these mutations affect the virus' spikes, the part that the virus particles use to latch onto and bind with other cells, and thereby transmit and spread the virus. Research on different strains is still ongoing, and it is too early to make any sweeping or definitive conclusions. But there is no evidence that these strains are able to transmit more easily, cause more serious symptoms or, crucially, render the vaccines useless. 

All the main vaccines being developed and, in some cases, already being administered, affect the spike proteins by training the immune system to attack the spikes. However, the body learns to attack multiple parts of the spike, so health authorities believe that the vaccines will still work perfectly well against these variants of the virus.

As the virus continues to mutate over time, though, it is quite possible that we will need to administer updated versions of the vaccines in the years ahead, possibly every year, much as we do for flu.