Omicron subvariant is more infectious than ‘original’, study says

The BA.2 subvariant of the omicron coronavirus variant, which quickly took over in Denmark, is more transmissible than the more common BA.1 and better able to infect vaccinated people, a Danish study showed.

The study, which analyzed coronavirus infections in more than 8,500 Danish households between December and January, found that people infected with the BA.2 subvariant were approximately 33% more likely to infect others, compared with those infected with BA.1 .

Worldwide, the “original” subvariant BA.1 accounts for more than 98% of onomicron cases, but its close cousin BA.2 quickly became the dominant strain in Denmark, dethroning BA.1 in the second week of January. .

“We conclude that the Omicron BA.2 is inherently substantially more transmissible than BA.1, and that it also has immunoevasive properties that further reduce the protective effect of vaccination against infections,” the study investigators said.

The study, which has not yet been peer-reviewed, was conducted by researchers from the Statens Serum Institut (SSI), the University of Copenhagen, Statistics Denmark and the Technical University of Denmark.

“If you were exposed to the BA.2 omicron in your home, you have a 39% chance of being infected within seven days. If you had been exposed to BA.1, the likelihood is 29%,” the report told Reuters. lead author of the study, Frederik Plesner.

This suggests that BA.2 is about 33% more infectious than BA.1, he added. BA.2 cases have also been reported in the United States, United Kingdom, Sweden and Norway, but to a much lesser extent than in Denmark, where it accounts for about 82% of cases.