problem vaccination gap
“Has a few more horsepower”: Virologist Drosten on the fitness advantage of omicron subtype BA.2
The virologist Christian Drosten from the Charité Berlin
© Michael Kappeler / DPA
The calls for easing the corona measures are getting louder and louder. But virologist Christian Drosten is still pressing the brakes. The reason for this is also the new omicron subtype BA.2.
Despite the high number of infections, the countries of Europe are relaxing again, corona measures are gradually being lifted and a return to pre-pandemic normality is sought. But Germany is still reluctant, politicians are sticking to the restrictions. Virologist Christian Drosten also does not see the time for the all-clear in the debate about possible easing. “There is one thing that hasn’t changed at first. That’s the vaccination gap in Germany. We’re not making any real progress there,” said the scientist from the Berlin Charité on Tuesday in the “Coronavirus Update” podcast on NDR-Info. Recently, the vaccination rate has even fallen again. In Denmark, for example, the corona restrictions have largely fallen due to the high vaccination rate – but the situation in Germany is not comparable. “That’s why there is no all-clear for Germany,” said Drosten.
The virologist pointed out that the new BA.2 variant from Omikron could have an even higher transmissibility than the BA.1 subtype currently predominant in Germany. Based on new data from Denmark, he assumes that BA.2 could possibly have a so-called fitness advantage and thus increased transmission ability. Drosten explained the assumed difference between the two subtypes with the metaphor of two cars and said with a view to BA.2: “The engine has a few more horsepower.”
With BA.1, on the other hand, he believes that the variant could evade the body’s immune response, which is why it spreads so quickly. The Danish study data published in the preprint – i.e. without review by peers – indicated that the risk of infection with BA.2 was significantly higher than with BA.1. The risk of passing on the virus is therefore also greatly increased in infected unvaccinated people, but reduced in vaccinated contact persons.
Easter holidays as a “planning horizon”
According to the latest weekly report from the Robert Koch Institute (RKI), the proportion of BA.2 in Germany is “still very low” in Germany at 2.3 percent in the second week of the year (week before: 1.4 percent) . The RKI writes about the subtype: “Internationally it is observed that BA.2 spreads more than BA.1”. This applies to Denmark and the United Kingdom, for example. Drosten said in the podcast that the proportion of BA.2 will probably also increase in Germany – but possibly more slowly than in other countries due to the infection protection measures in force. However, due to the lack of data, it is not yet possible to predict more precisely.
According to the virologist, he sees a time threshold and a “planning horizon” for the relaxation of the corona situation in the coming Easter holidays. “We clearly have the finding in Germany that the transmission networks are currently being fed from school operations. The Easter holidays will put a stop to that at the latest,” he said. The then warmer temperatures should also have a reducing effect on the incidences. It remains to be seen whether BA.2 will have “completely taken over the field” by then.
Omicron infection does not replace vaccination
Drosten said that the “ideal immunization” is complete vaccination protection with three doses of vaccine, on the basis of which one then becomes infected with the virus once or more often and thus develops such a strong immunity “without having to accept severe courses”. Anyone who has gone through this “is then really resilient for years, immune and will not reinfect themselves again,” said Drosten.
With a view to the many unvaccinated people in Germany, he repeated his warning against allowing an infection. He strongly criticized the way of thinking that an infection with one of the omicron variants could replace a vaccination and pointed to the high probability of repeated infections. That is why the calculation “of the omicron infection as a vaccination through the back door” simply does not work.