Omicron sublineages recombination creates new COVID variant

The Finnish Institute for Health and Welfare (THL) and the University of Helsinki have found a new variant resulting from recombination between two omicron sublineages, BA.1 and BA.2, said THL in a press release on Thursday.

THL sequences weekly a sample of positive coronavirus samples as part of its variant surveillance activities, carried out in collaboration with the University of Helsinki and the Institute for Molecular Medicine Finland (FIMM).

Through variant monitoring, a recombinant virus containing genes from two omicron sublineages BA.1 and BA.2, has been detected. So far, there are 11 cases, located in the Western Ostrobothnia Hospital District. THL is consequently intensifying variant monitoring in the Western Ostrobothnia Hospital District.

If two different coronavirus variants are present in one infected person at the same time, it is possible that the viruses will multiply in the same cell and exchange parts of their genomes, i.e. recombine. This creates a recombinant virus that contains parts of the genomes of both parental viruses. Mutation and recombination are typical evolutionary mechanisms observed in coronaviruses.

The newly found recombinant coronavirus is not known to have caused increased transmission or severity of illness compared to omicron. With several coronavirus lineages circulating in the population, recombinants are likely to emerge and have been reported increasingly from different countries.

The spread of new variants can be prevented like other coronavirus variants following the recommendations on vaccination, maintaining good hand hygiene, wearing masks and maintaining safe distances.

The emergence of virus variants is very common and is a part of the natural circulation of viruses. Variants disperse and may displace earlier variants or be overcome by other variants, as has been repeatedly observed during the coronavirus pandemic.