Transmission electron microscope image of SARS-CoV-2. Image: NIAID/Flickr CC BY 2.0
We already know from the first omicron variant BA.1 that it is significantly more contagious than earlier coronavirus variants. Now a subtype, BA.2, has emerged. At least 400 people have been infected with it during the first 10 days of January in the UK. And it has already been detected in more than 40 other countries worldwide.
The PANGO directory of coronaviruses, which is regularly updated by scientists from the universities of Oxford, Edinburgh and Cambridge, lists Denmark as the most affected area, with 79% of the cases detected so far.
It is followed by Great Britain (6%), India (5%), Sweden (2%) and Singapore (2%). However, it should be noted that detection of the subtype depends on the ability of individual health systems to sequence PCR tests.
Danger posed still unknown
The rapid spread of the new subtype suggests that it could be even more contagious than the original omicron variant. The UK Health Security Agency (UKHSA) has classified BA.2 as a “variant under surveillance.”
“It is the nature of viruses to evolve and mutate, so it’s to be expected that we will continue to see new variants emerge as the pandemic goes on,” said Meera Chand, Incident Director at UKHSA. “Our continued genomic surveillance allows us to detect them and assess whether they are significant.”
For subtype BA.2, that analysis is still underway.
“So far, there is insufficient evidence to determine whether BA.2 causes more severe illness than omicron BA.1,” Chand said.
Vaccination remains important
UK Health Secretary Sajid Javid added that the emergence of the new variant shows the continued importance of vaccination: “I encourage you to give yourself and your loved ones the best protection possible and get boosted now.”
French epidemiologist Antoine Flahault told the French news agency AFP: “What surprised us is the rapidity with which this sub-variant, which has been circulating to a great extent in Asia, has taken hold in Denmark.”
Meanwhile, infections with subtype BA.2 have so far not been more severe than with subtype BA.1.
French Health Minister Olivier Véran remains relaxed about BA.2: “What we know for now is that [it] more or less corresponds to the characteristics that we know of omicron,” he told AFP.
This article was first published by DW and has been republished here with permission.