Now, an Omicron variant, BA.2, accounts for almost half of all Danish Omicron-cases
So far, three subvariants of Omicron have been described: BA.1, BA.2 and BA.3. Worldwide, BA.1 account for most of Omicron-cases. However, in Denmark BA.2 is gaining ground.
The subvariant BA.2 accounted for 20% of all covid-19-cases in Denmark in week 52 increasing to approximately 45% in week 2. During the same period, the relative frequency of BA.1 has dropped.
Other countries also experience an increase in BA.2 cases: E.g. Great Britain, Norway and Sweden – but seemingly their increase in numbers are so far not on the same level as in Denmark.
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.
Such differences can lead to different properties for instance concerning infectiousness, vaccine efficiency or severity. So far, there is no information as to whether BA.1 and BA.2 have different properties, but Statens Serum Institut (SSI) is continually working to investigate this matter.
Initial analysis shows no differences in hospitalisations
Initial analysis shows no differences in hospitalisations for BA.2 compared to BA.1. Analyses regarding infectiousness and vaccine efficiency etc. are ongoing, including attempts to cultivate BA.2 in order to perform antibody neutralization studies. It is expected that vaccines also have an effect against severe illness upon BA.2 infection.