Comment: Do Omicron’s many sub-variants mean the virus mutates faster?

Worryingly, even if one is infected with the Omicron subvariant BA.1, reinfection is still possible with sublines of BA.2, BA.4, and BA.5 due to their ability to evade immune responses.


You would think SARS-CoV-2 is a superfast frontrunner when it comes to mutations. But actually the virus mutates relatively slowly. Influenza viruses, for example, mutate at least four times faster.

However, SARS-CoV-2 has “mutational sprints” for short periods of time, according to our study. During one of these sprints, the virus can mutate four times faster than normal for several weeks.

After such sprints, the line has more mutations, some of which can provide an advantage over other lines. Examples include mutations that can help make the virus more transmissible, cause more serious disease, or evade our immune response, creating new variants.

Why the virus undergoes mutational sprints leading to the emergence of variants is unclear. But there are two main theories about Omicron’s origin and how it accumulated so many mutations.

First, the virus may have evolved into chronic (long-term) infections in people with weakened immune systems (a weakened immune system).

Second, the virus could have “jumped” to another species before reinfecting humans.


Mutation is not the only way in which variants can arise. The Omicron XE variant appears to result from a recombination event. Here, one patient was simultaneously infected with BA.1 and BA.2. This co-infection led to a “genome swap” and a hybrid variant.

Leave a Comment