Are all new variants the same?
They all share a remarkably similar set of mutations in the virus’s spike protein – the part that attaches to human cells – but they are not identical. They all originated in areas where sharp peaks have occurred in Covid cases recently.
Why did they show up at the same time?
Scientists are not sure. They are speculated to be the product of general evolutionary pressures. One theory is that patients on long-term Covid allow the virus to mutate more efficiently. The UK, South Africa and Brazil all have many such cases.
Can they avoid vaccines?
Pfizer and AstraZeneca believe their vaccines will still work against the UK variant. The jury is not yet familiar with the other two. There is some lab work to suggest that the South African variant can sometimes evade existing antibodies (produced by vaccines or natural infection). However, experts say a vaccine is unlikely to stop working suddenly. They are more likely to gradually become less effective as the virus changes.
Is this pattern normal?
Yes, respiratory viruses tend to “float” over time, and vaccines need to be constantly adjusted to keep up with them. For example, this happens every year with the seasonal flu shot.
How simple is the vaccine update process?
In theory it should be pretty easy. As long as the changes to be made to vaccines are modest (just four or five changes to the more than 1,000 amino acids of the spike protein), new vaccines can be produced quickly and without lengthy regulatory approval. The new RNA vaccines such as Pfizer’s can also be modified more quickly than conventional vaccines.