All viruses, including Kovid-19, mutate continuously. Most mutations have little or no effect on their ability to transmit from one person to another or make them seriously ill. When a virus mutates multiple times, it is considered a separate lineage. But a virus lineage is not considered a variant unless it has carried many unique mutations.
This is the reason for the BA genealogy which the World Health Organization has described as Omicron. Since the oomicron spreads rapidly and has many opportunities to mutate, it has many specific mutations of its own. This gives rise to sub-variants. We have also seen sub-variants of earlier variants such as the delta variant.
Why are sub-variants such a big problem?
There is evidence that these oomicron sub-variants specifically re-infect people ba.4 and ba.5. There is also concern that these sub-variants may infect people who have received a dose of anti-Covid-19 vaccine. So we may see a sharp increase in COVID cases in the coming weeks and months due to re-infection, as we are already seeing in South Africa. However, recent studies suggest that the third dose of the anti-coronavirus vaccine is most effective in preventing Omicron.
Does the virus mutate rapidly?
SARS-CoV-2 appears to mutate most rapidly, but the virus actually mutates slowly. For example the influenza virus mutates at least four times more rapidly. Mutation is not the only way for forms of a virus to emerge. Omicron’s XE form is the result of a reconfiguration. This happens when the same patient is infected with both BA.1 and BA.2 at the same time.
What can we see in the future?
As far as the spread of the virus is concerned, we will continue to see the new lineage and form of the virus. Since Omicron is the most common form now, it is likely that we will see more sub-variants of Omicron. Scientists will continue to watch for new mutations and forms created by recombination. They will also use genomic technologies to predict how they arise and whether they have any effect on the behavior of the virus. This will help us limit the spread and impact of variants and sub-variants. It will also guide the development of effective vaccines against multiple or specific variants.