Also Read | The health nudge is merely a mirage"All manufacturers, Pfizer-BioNTech, Moderna, Oxford-AstraZeneca and others are looking at how they can improve their vaccine to make sure that we are ready for any variant - there are about 4,000 variants around the world of COVID now."While thousands of variants have arisen as the virus mutates on replication, only a very small minority are likely to be important and to change the virus in an appreciable way, according to the British Medical Journal."We have the largest genome sequencing industry - we have about 50% of the world's genome sequencing industry - and we are keeping a library of all the variants so that we are ready to respond - whether in the autumn or beyond - to any challenge.