By now, everyone is aware of the Omicron variant of SARS-CoV-2, the virus that results in COVID. This variant of concern has altered the course of the pandemic, ushering in a grand increase in cases of Covid-19 around the world.
New Omicron sub-variants that are identified as BA.2, BA.4 and now BA.5 are becoming the new covid-related subjects for discussion. The concern is that these sub-variants may drive people to become reinfected, leading to another rise in covid cases.
The most prevalent questions on a lot of people’s minds include;
Why do we keep seeing more of these new sub-variants?
Is the virus mutating faster?
What is the significance of the future of COVID?
SARS-CoV-2 and every other virus mutate constantly. A large majority of mutations have little or no effect on the ability of the virus to transmit from one individual to another or to result in severe disease.
When a virus amasses a significant amount of mutations, it is deemed a distinct lineage (relatively a different branch on a family tree).
However, a viral lineage has not been labeled a variant until it has amassed several unique mutations known to strengthen the ability of the virus to transmit or result in more severe disease.
Omicron has circulated quickly, representing almost all new cases with genomes sequenced globally.
Because Omicron has spread quickly and has had a lot of chances to mutate, it has also accumulated certain mutations of its own. These have given an increase to several sub-lineages, or sub-variants.
Omicron sub-variants – precisely the BA.4 and BA.5 variants are very active at reinfecting people who have had previous infections from BA.1 or other lineages. There is also a concern that these sub-variants would infect people who have been vaccinated.
There may be an abrupt rise in COVID cases in months due to reinfections, which we are already seeing in South Africa.
Nonetheless, modern research indicates that a third dose of the COVID vaccine is the most practical way to stall the spread of Omicron including sub-variants and prevent COVID-associated hospital admissions.
SARS-CoV-2 is known to be a super-speedy front-runner when it comes to mutations; however, the virus mutates relatively slowly. Influenza viruses, for instance, mutate at least four times faster.
Research implies that it also has some “mutational sprints” for a short duration. During one of these sprints, the virus would mutate four times faster than ordinary for a few weeks.
After this sprint takes place, the lineage has more mutations, some of which may give an advantage over other lineages.
The two major assumptions about the origins of Omicron and how it amassed a lot of mutations.
First of all, the virus could have evolved in chronic (prolonged) infections in people who are immunosuppressed (or have a weakened immune system).
Secondly, the virus could have “jumped” to another species, before infecting people again.
Of course, Mutation is not the only known way variants can be created. The Omicron XE variant appears to have resulted from a recombination event. This is where a solitary patient was infected with the BA.1 and BA.2 variant at the same time. This coinfection would result in a “genome swap” and a hybrid variant
Some major instances of recombination in SARS-CoV-2 have been reported in the Delta and Omicron variants. This has led to what has been dubbed Deltacron.
So far, recombinants do not seem to have higher transmissibility or result in more severe outcomes. But this could alter rapidly with new recombinants. So scientists are closely evaluating them.
In conclusion, since Omicron is the most common variant currently, it is likely we will see more Omicron sub-variants, and potentially recombinant lineages.