2 new Omicron subvariants detected by South African scientists

South African scientists have detected two new sublineages of the Omicron variant of SARS-CoV-2, the virus that causes COVID-19.

According to Tulio de Oliveira, Director of the Centre for Epidemic Response & innovation, South Africa, the lineages have been named BA.4 and BA.5.

However, he said, the detection was no cause for alarm and it was too early to assess the impact of this emergence on the virus' epidemiology.

In a series of tweets, de Oliveira said the lineages have not caused a spike in infections in South Africa and have been found in samples from a number of countries.

"New Omicron BA.4 & BA.5 detected in South Africa, Botswana, Belgium, Germany, Denmark, and U.K. Early indications that these new sublineages are increasing as a share of genomically confirmed cases in South Africa. No cause for alarm as no major spike in cases, admissions or deaths in South Africa," de Oliveira tweeted on Monday.

"Despite the increase in the percentage of genomes, BA.4 and BA.5 are not causing a spike in infections in South Africa. The same is seen for hospitalisation and deaths, which in South Africa is at a record low," he wrote.

The two lineages have similar mutations on their spike proteins, the part of the virus that helps the virus to enter and infect human cells, to the BA.2 sublineage which appears to be more infectious than the original Omicron strain, Oliveira said, adding they also have some additional mutations.

The Omicron variant of coronavirus was first discovered in Botswana and South Africa in November last year.

Earlier the XE strain, a recombinant of BA.1 and BA.2 sub variants of Omicron, was reported in many countries, including India.

"Given the current high level of transmission worldwide, it is likely that further variants, including recombinants, will continue to emerge. Recombination is common among coronaviruses and is regarded as an expected mutational event," the WHO said in a recent update.