Has Omicron evolved to become more dangerous? - Hot Air

I wrote about the new Omicron subvariants, BA.4 and BA.5, a few weeks ago.

Worse, because natural immunity from Omicron appears to last only a few months, a prior infection is no real defense to BA.4 and BA.5.

Researchers in Japan say they have evidence that BA.4 and BA.5 are better at spreading in the lungs than their grandparent was.

According to preliminary data from Kei Sato at the University of Tokyo and colleagues, BA.4, BA.5 and BA.2.12.1 may have evolved to refavour infection of lung cells, rather than upper respiratory tract tissue – making them more similar to earlier variants, such as Alpha or Delta….

Professor Sato’s experiments indicate that BA.4, BA.5 and BA.2.12.1 replicate more efficiently in human lung cells than BA.2, while further experiments in hamsters suggest that BA.4 and BA.5 may cause more severe disease.

According to this site, BA.4 and BA.5 represent a significant majority of cases over the past 60 days in South Africa, the country that’s been hit hardest by the new subvariants.

Over the past 60 days, BA.4 accounts for 63 percent of confirmed cases while BA.5 accounts for 20 percent more.

South African researcher Tulio de Oliveira, who sounded the global alarm on Omicron last year, reports that the BA.4 and BA.5 wave has been the *least* deadly wave experienced by the country so far.

and UK since BA.4 and BA.5 either aren’t dominant yet or haven’t been dominant long enough to allow us to draw a conclusion about how deadly they might be.

Maybe that’s because BA.4 and BA.5 aren’t as virulent as feared, but it may also be that medicine has caught up to the virus and is transforming COVID cases that would have been fatal a year ago into short hospital stays.

Look back at the excerpt above and you’ll see that Japanese researchers found that BA.2.12.1, not just BA.4 and BA.5, appears to reproduce more efficiently in the lungs than the original Omicron.

In fact, the number of people hospitalized with COVID is now double what it was in mid-April, more circumstantial evidence that Omicron’s subvariants really are more virulent.