Covid-19 Omicron outbreak: New variant BA.2 could be worse than predecessors for public health, study warns

Experts are worried a new subvariant of Omicron could see a devastating surge in infections and deaths around the world just as the pandemic appears to be retreating.

Eric Feigl-Ding, a Harvard-trained epidemiologist who was among the first researchers to sound the alarm about the seriousness of Covid-19, wrote that the subvariant — BA.2 — is "seriously bad news".

"Even the World Health Organisation is getting very concerned about BA.2 variant outcompeting and displacing old Omicron," he wrote on social media.

He wrote that news out of Denmark, where the subvariant represents 90 per cent of all new cases, suggests it is having significant health impacts.

Photo / Supplied

"Here is what is happening in the country with the most BA.2 variant so far. (Denmark) has been BA.2 dominant for weeks and have now almost no mitigations either … now their excess deaths are spiking again."

Dr Feigl-Ding shared a table showing the gap between those dying because of Covid-19 and those simply dying with the virus was widening, and a separate graph from Johns Hopkins University, shared last week, that showed a major surge in deaths since November 1, 2020.

7) Let’s look at it this way—BA2 is much more aggressive than anything —both pink and green below are BA2 — but the green H78Y subtype of BA2 extra aggressive it seems. Meanwhile BA1 old Omicron near extinct in 🇩🇰! That doesn’t happen by chance. We need to raise BA2 as VOC asap! pic.twitter.com/veJRPOOwEa

— Eric Feigl-Ding (@DrEricDing) February 18, 2022

In the study, which exposed hamsters to different variants, Sato writes: "The viral RNA load in the lung periphery and histopathological disorders of BA.2 were more severe than those of BA.1 and even B.1.1.

"Together with a higher effective reproduction number and pronounced immune resistance of BA.2, it is evident that the spread of BA.2 can be a serious issue for global health in the near future.

People walk on a pedestrian shopping street during the Omicron wave in Cologne, Germany. Photo / Getty Images

"In summary, our data suggests the possibility that BA.2 would be the most concerning variant to global health. Currently, both BA.2 and BA.1 are recognised together as Omicron and these are almost undistinguishable.

"Based on our findings, we propose that BA.2 should be recognised as a unique variant of concern, and this SARS-CoV-2 variant should be monitored in depth."