Scientists worry as more contagious BA.2 Omicron sub-variant spreads

Just before the world heaves a sigh of relief that the COVID-19 pandemic may be retreating, infectious disease experts are worried that a new Omicron sub-variant tagged BA.2, could be worse than its predecessors for public health, even as they warn that it could trigger a devastating surge in infections and deaths around the world.

As the omicron surge continues to decline, the experts are keeping a close eye on the BA.2, identified as an even more contagious version of the highly contagious Omicron that appears to spread even more easily.

As scientists are on the alert, recent research found that one of the remaining antibody treatments for COVID-19 may be less effective against BA.2, which has quickly overtaken the original Omicron in many countries.

A COVID-19 expert, Dr Eric Feigl-Ding, who described the development as “seriously bad news”, noted that in Denmark, where the subvariant represents 90 per cent of all new cases, it s having a significant health impact.

Feigl-Ding, a Harvard-trained epidemiologist who was among the first researchers to sound the alarm about the seriousness of Covid-19, noted: “Even the World Health Organisation is getting very concerned about BA.2 variant outcompeting and displacing old Omicron.

“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.”

According to a virologist at the University of Massachusetts Medical School, Dr. Jeremy Luban: “ There are going to be plenty of people getting sick and ending up on respirators and dying because of BA.2,  especially among the millions who still aren’t vaccinated.”

He noted that even though vaccination and prior infection does appear to protect people against BA.2, this version of the virus seems somewhat better at evading the immune system than the original omicron. This increases the concern that it could drive growth in new cases.

Luban agrees the most likely scenario is that BA.2 will just extend the omicron wave, saying it’s impossible to rule out the possibility of another surge.

“It may be that the virus has to get to somewhere like 5-7 per cent, and then all of a sudden once it has a foothold like that, it will take off,” Luban says.

Earlier, the World Health Organisation’s Technical Lead on Covid-19, Maria Van Kerkhove, had warned: “We already know that Omicron has a growth advantage … compared to other variants of concern. But we know that BA.2 has a growth advantage even over BA.1. This virus continues to be dangerous. This virus transmits very efficiently between people but there’s a lot that you can do.

“We need to drive transmission down. Because if we don’t, we will not only see more cases, more hospitalisations, more deaths, but we will see more people suffering from Long Covid and we will see more opportunities for new variants to emerge. “So it’s a very dangerous situation that we’re in, three years in,”van Kerkhove warned.

After an Omicron surge that lasted for three-and-a-half months, the average number of global daily cases dropped for a third week in a row last week, falling back by 22 per cent to 1.97 million

But lab work out of Japan reveals there is still some cause for concern. A study led by Kei Sato from the University of Tokyo posted online showed that 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.

“In summary, our data suggest 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 indistinguishable.

“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,” Sato wrote, saying the subvariant needs to be more closely monitored.

In his views, Nathan Grubaugh, an associate professor of epidemiology at the Yale School of Public Health, stated: “A lot of us were assuming that it was going to quickly take off in the United States just like it was doing in Europe and become the new dominant variant.”

But so far that hasn’t happened. Instead, BA.2 has slowly but steadily spread even as the omicron surge continued to dissipate. The fear is that spread may be on track to rapidly accelerate in the near future. BA.2 appears to be doubling fast.

According to Samuel Scarpino, the manager director of pathogen surveillance at the Rockefeller Foundation: “If it doubles again to 8 percent,  that means we’re into the exponential growth phase and we may be staring at another wave of COVID-19 coming in the US. And that’s of course the one we’re really worried about. We’re all on the edge of our seats.”

Grubaugh however says it’s probably not going to lead to a new wave of cases and that the most likely thing that’s going to happen is that it might slow down the decrease in cases.

Some experts think it is unlikely BA.2 will trigger a massive new surge because so many people have immunity from prior infections and vaccination at this point.

They say even though BA.2 doesn’t appear to make people sicker than the original omicron, just slowing down the decline in new cases would translate to more serious illness and death


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