A new COVID-19 Omicron sub-variant known as BA.2 has been detected in the United States, officials said, coming after officials in the United Kindom and Denmark published reports on the strain in recent days.
“There is still uncertainty around the significance of the changes to the viral genome, and further analyses will now be undertaken,” the UK Health Security Agency said in a news release.
UK researchers said an early analysis suggests BA.2 is more transmissible than the first Omicron strain, which was named as a “variant of concern” by the World Health Organization in November. However, the team said that they have not been able to find a meaningful difference between the original strain and BA.2.
There have been about 400 confirmed BA.2 cases in 40 countries. The first was confirmed in December, the UK agency said.
“So far, there is insufficient evidence to determine whether BA.2 causes more severe illness than Omicron BA.1, but data is limited and UKHSA continues to investigate,” Dr. Meera Chand, COVID-19 incident director at the UK Health Security Agency, said in a statement.
“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,” Chand continued. “Our continued genomic surveillance allows us to detect them and assess whether they are significant.”
Officials in Denmark said that nearly half of the COVID-19 test samples they sequenced are BA.2. By the second week of January, its share had risen to about 45 percent of total cases.
“During the same period, the relative frequency of BA.1 has dropped,” said a statement from the Statens Serum Institut, a Danish health agency, referring to BA.1—the name of the initial Omicron COVID-19 variant. “BA.1 and BA.2 have many differences in their mutations in the most important areas. In fact, the difference between BA.1 and BA.2 is greater than the difference between the original variant and the Alpha variant.”
An initial analysis of BA.2 cases suggests there is no difference in hospitalizations, compared with the BA. 1 sub-variant, the health agency said. It’s not clear if current vaccines are effective against it, either.
Other than the UK and Denmark, Norway, France, India, and Sweden have also reported cases of the Omicron offshoot, according to media reports. The subvariant has also been detected in the United States in Washington state, officials said.
The Washington State Health Department confirmed two BA.2 cases earlier this month, reported KOMO News.
“It’s too early to tell if we are going to see more cases of this variant,” Washington health department spokesperson Shelby Anderson told the local channel. “So far, fewer than 100 confirmed BA.2 cases in the U.S. have been reported.”
And at least three cases have been detected at Houston’s Methodist Hospital, officials told the Washington Post.
“The good news is we have only three,” James Musser, director of the Center for Molecular and Translational Human Infectious Diseases Research at Houston Methodist, told the outlet. “We certainly do not see the 5 percent and more that is being reported in the UK now and certainly not the 40 percent that is being reported in Denmark.”