Are all new variants the same?
All share a remarkably similar set of mutations in the virus spike protein – the part that locks onto human cells – but they are not the same. All of them have occurred in areas where there have been recent strong spikes in Covid cases.
Why did they appear at the same time?
Scientists are not sure. It is assumed that they are the product of common evolutionary pressures. One theory is that patients who have Covid for an extended period allow the virus to mutate more efficiently. The UK, South Africa and Brazil all have many such cases.
Can they escape vaccines?
Pfizer and AstraZeneca believe their vaccines will still work against the UK variant. The jury is still out on the other two. Some lab work suggests that the South African variant may end up escaping existing antibodies (produced by vaccines or natural infection) from time to time. However, experts say that a vaccine is unlikely to suddenly stop working together. They are more likely to become less effective in increments as the virus changes.
Is this pattern normal?
Yes, respiratory viruses tend to “drift” over time and vaccines need to be constantly changed to keep pace. This happens every year with the seasonal flu shot, for example.
How simple is the vaccine update process?
In theory, this should be pretty straightforward. As long as the changes to the vaccines are modest (only four or five changes to the more than 1000 amino acids of the spike protein), new vaccines can be produced quickly and without lengthy regulatory approval. New RNA vaccines like the one manufactured by Pfizer can also be changed more quickly than conventional vaccines.