Are all new variants the same?
They all share a remarkably similar set of mutations in the virus’s flagship protein – the part that attaches to human cells – but are not identical. All have emerged in areas where there have been sharp recent rises in Covid cases.
Why did they appear at the same time?
Scientists are not sure. It is speculated that they are the product of usual evolutionary pressures. One theory is that patients who have Covid for an extended period of time allow the virus to mutate more efficiently. The United Kingdom, South Africa and Brazil have many such cases.
Can vaccines be avoided?
Moderna Inc. announced on January 25 that its Covid-19 vaccine was producing virus-neutralizing antibodies in laboratory tests against new coronavirus variants found in the United Kingdom and South Africa.
Pfizer and AstraZeneca think their vaccines will still work against the UK variant. The jury remains out of the other two. There is some laboratory work suggesting that the South African variant may end up avoiding existing antibodies (produced by vaccines or natural infections) sometimes.
However, experts say a vaccine is unlikely to suddenly stop working together. They are more likely to be less effective as the virus changes.
Is this pattern normal?
Yes, respiratory viruses tend to “drift” over time and vaccines need to be constantly modified to stay up to date. This happens every year with seasonal flu, for example.
How simple is the vaccine update process?
In theory it should be pretty straightforward. As long as the changes that need to be made to vaccines are modest (only four or five changes to the more than 1,000 amino acids of the ear protein), new vaccines can be produced quickly and without long regulatory approval. New RNA vaccines such as the one manufactured by Pfizer can also be changed more quickly than conventional vaccines.