Omicron subvariant more transmissible, but may not cause worse illness — expert
Eran Segal says infection with original Omicron could offer protection against BA.2 mutation; Danish study: Substantially more contagious strain could better evade vaccines
An Israeli expert will tell ministers on Tuesday that a descendant of the Omicron variant that has been found in more than 50 countries, including Israel, could be 1.5 times as contagious as the original strain.
Prof. Eran Segal of the Weizmann Institute, a top government adviser on the pandemic, will present data on the variant at a meeting of the coronavirus cabinet, the Kan public broadcaster reported.
Ahead of the meeting, Segal told Kan that while the new BA.2 strain appeared to be very contagious, initial signs indicated that it did not cause worse illness than the original Omicron variant.
“It seems that it is more contagious, even more so than the Omicron; however, it appears not to cause illness that is more serious than [the original] Omicron,” said Segal, a computational biologist.
Segal noted that the BA.2 strain has become dominant in Denmark, where it is causing a rise in infections, just as the country was beginning to come out of the surge.
However, he said that despite a rise in general hospitalizations as a result of the virus in the Scandinavian nation, there had not been an increase in the number of patients who were seriously ill from the new strain. Denmark scrapped most of its pandemic restrictions on Tuesday.
Segal said he expected 4.5 million people to be infected in Israel by the end of the current wave, nearly half the country, and that he believed infections from the original Omicron BA.1 variant would provide protection against the BA.2 strain.
“Although we are after the peak of the disease, the chances of infection are still high and we need to be careful,” Segal said. “We can be optimistic, though, as we are seeing a decrease in infections.”
A study in Denmark released on Monday found people infected with BA.2 were 33 percent more likely to infect others compared to BA.1, which was already considered more contagious than Delta and earlier strains. The study analyzed 8,500 Danish households between December and January.
“We conclude that Omicron BA.2 is inherently substantially more transmissible than BA.1 and that it also possesses immune-evasive properties that further reduce the protective effect of vaccination against infection,” the researchers said.
The study has not yet been peer-reviewed and was carried out by researchers at Statens Serum Institut (SSI), Copenhagen University, Statistics Denmark and Technical University of Denmark.
“If you have been exposed to Omicron BA.2 in your household, you have 39% probability of being infected within seven days. If you instead had been exposed to BA.1, the probability is 29%,” lead study author Frederik Plesner told the Reuters news agency.
A report on the BA.2 variant is expected to be presented at Tuesday’s meeting of the coronavirus cabinet, a select panel of ministers who form COVID policy in Israel.
The new variant has raised concerns just as Israel appears poised to begin putting a massive wave of Omicron-fueled infections behind it. While case numbers have begun to ebb, the number of seriously ill has remained high, and the death toll has continued to climb.
At the start of the meeting, Prime Minister Naftali Bennett warned that Israel “can expect another difficult week and a half.”
Earlier, Health Minister Nitzan Horovitz said he expected the Omicron wave to continue for three more weeks, Ynet reported.
The government has continued to urge diligence in observing public health regulations.