Two omicron subvariants gain a bigger foothold in the U.S.



The omicron subvariants BA.4 and BA.5. The spread of omicron and its subvariants has been ferocious. Within weeks, that version of the virus — now referred to as BA.1.1 — had overtaken the delta variant as the dominant strain. Since then, more transmissible omicron subvariants have emerged and subsequently taken hold: The current dominant strain is BA.2.21.1, which pushed out BA.2, which pushed out BA.1.1. None of the omicron subvariants have been found to cause more severe disease than the original omicron strain.


58.76% objective
55.13% positive


ARS TECHNICHA - With BA.2.12.1 now dominant in US, experts eye new subvariants BA.4 and BA.5 [Updated]
-9.53% LESS objective
1.6% MORE positive

Update 6/7/2022 2:00 pm ET: The Centers for Disease Control and Prevention updated its prevalence estimates for coronavirus variants Tuesday and has now provided separate estimates for omicron subvariants BA.4 and BA.5, which were previously reported together. But BA.2.12.1's reign may end as quickly as it began, with yet another batch of omicron subvariants gaining ground—BA.4 and BA.5—and threatening to cause more breakthrough infections. But, while BA.2.12.1 continues its rise, omicron subvariants BA.4 and BA.5 are gaining ground. A recent preprint study posted by researchers in Japan reported that BA.2.12.1, BA.4, and BA.5 replicate better in human lung cells than the previous reigning subvariant, BA.2. But, BA.4 and BA.5 cause more severe disease in hamsters than both BA.2 and BA.2.12.1.

THE WASHINGTON POST - Moderna seeking FDA authorization of omicron-specific booster shot
-8.39% LESS objective
7.62% MORE positive

But the omicron variant has mutated so quickly that several new subvariants have emerged that are even better at evading the immune system’s defenses. Even if the updated booster provides less protection against later omicron subvariants than against BA.1, it will probably still be more effective against them than the company’s existing booster, Moderna President Stephen Hoge said. AdvertisementSoon after the omicron variant was identified in South Africa late last year, Moderna said it was developing shots specifically designed to fight the variant. Pfizer and BioNTech announced the same plan, although they have not yet released data on their updated vaccine. Globally, new coronavirus cases are still declining after the omicron variant triggered tens of millions of new cases worldwide, driving up infections during the winter.

HEALTH - Omicron Infection Timeline: When Symptoms Start and How Long They Last
-9.36% LESS objective
1.71% MORE positive

In that case, here's what a typical timeline of an Omicron infection looks like, from exposure to immunity. That incubation period is just about three days, compared to the Delta variant's five-day incubation period, and the original SARS-CoV-2 virus' incubation period of more than 5 days. It also looks like vaccination is a key factor in how much immunity one can get from an Omicron infection. But Omicron infection in unvaccinated people may not provide much protection against non-Omicron variants. And even with a certain level of immunity—whether it's from just an Omicron infection, or from an Omicron infection plus prior vaccination—it's still important to monitor and follow CDC guidelines depending on your community's risk level.

SKY - COVID-19 alert level in UK reduced - as Omicron BA.4 and BA.5 reclassified as variants of concern
-7.28% LESS objective
0.04% MORE positive

The UK's coronavirus alert level has been reduced - as two rare types of Omicron have been reclassified as variants of concern. New Omicron types may have 'immune escape'Despite significant and consistent falls, two new sub-lineages of Omicron - BA.4 and BA.5 - have been reclassified as variants of concern by the UK Health Security Agency (UKHSA). Only 115 probable or confirmed BA.4 cases have been identified in the UK as of 20 May. Dr Meera Chand, from the UKHSA, said: "The reclassification of these variants as variants of concern reflects emerging evidence on the growth of BA.4 and BA.5 internationally and in the UK. The reclassification of BA.4 and BA.5 as variants of concern comes after UK experts recommended an autumn COVID booster jab for some people.