New subtype of omicron could prolong infection wave

Berlin / Copenhagen. Experts believe that an omicron sub-variant that is perhaps easier to transmit could lead to an extension of the current wave of infection. “BA.2 will reign with us too,” immunologist Carsten Watzel wrote on Twitter on Monday. This can lengthen the omicron wave. The Secretary General of the German Society of Immunology referred to a study from Denmark on the omicron BA.2 subtype which has not yet been reviewed by external experts.

According to the study, the risk of developing BA.2 is more than double the risk of developing subtype BA.1. This applies to both the group of those who have not been vaccinated, as well as people with basic protection and those who have been reinforced. The study says the risk of transmission of the virus is significantly increased in infected people who are not immunized, but not in those who have been vaccinated and boosted. BA.1 was so far prevalent in Germany, but BA.2 does exist.

BA.2 can lead to more transfers in schools and daycares

The researchers wrote that vaccination also had an effect against infection, transmission, and critical illness with BA.2, albeit lower compared to previous variants. They note that the higher susceptibility and transmissibility of BA.2 in the unvaccinated will likely lead to a further increase in transmission in unvaccinated children, for example in schools and day care centres.

For preprint, scientists in Denmark looked at infections with BA.1 and BA.2 in homes. The events were considered based on about 8,500 cases called primary cases at the end of December and the beginning of January. “We conclude from this that Omikron BA.2 is inherently more transferable than BA.1,” the conclusion states. BA.2 also possesses immune evading properties that reduce the protective effect of vaccination against infection. However, transmission is not increased by vaccination.

According to the latest weekly report from the Robert Koch Institute (RKI), Germany’s BA.2 is “still very low” in Germany at 2.3 percent in the second week of the year (previous week: 1.4 percent). RKI writes about the subtype: “Internationally, BA.2 has been observed to be more prevalent than BA.1.” This applies to Denmark and the United Kingdom, for example. However, clinically and epidemiologically, there is still no reliable knowledge of other properties.