What We Know About "Stealth Omicron"

[marmar]

What We Know About “Stealth Omicron”

BY SARAH BRANER
JAN 28, 20221:40 PM


(Slate) The omicron wave is beginning to slow in some parts of the country (though hospitals in many places remain overwhelmed). But you may have recently heard about a new member of the COVID cast: BA.2, a relative of omicron. This new relative of the variant we’ve all gotten to know is popping up in dozens of countries, and its nickname, “stealth omicron,” is causing alarm for some; tabloids in the U.K. are getting particularly fearmongery about it. But how much do you really need to worry about it? So far, not much. Here’s what we know.

What’s with this “stealth” business?

According to Peter Chin-Hong, an infectious disease specialist at the University of California, San Francisco, it’s not called “stealth omicron” because a diagnostic PCR test won’t detect it. Rather, it’s “stealth” because it’s a little tricky to determine its lineage—that is, how it relates to other variants. BA.2 is a sublineage of the omicron variant, but it has a specific quirk in its genome (it doesn’t have what’s called an “S-gene deletion”) that can confound some sequencing methods. That means it’s hard to identify as the BA.2 sublineage, not that it’s hard to identify as SARS-CoV-2. PCR tests should still be able to determine if someone is infected with SARS-CoV-2.

Where has it been found?

A lot of our early information is coming out of Denmark, which has a more robust sequencing program than the United States. It’s also been found in more than 50 other countries, like the United Kingdom, India, Sweden, and Singapore, and may be responsible for a rise in cases in Hong Kong. BA.2 has made its way to the United States, with recent reports of its detection coming out of California, Texas, Connecticut, and Washington state.

Is it more contagious than “regular” omicron?

It’s still too early to know for sure, but reports from the Danish government and its top infectious disease authority, the Statens Serum Institut, suggest that BA.2 could be 1.5 times more contagious than omicron. Emphasis on could.

Does it cause more severe disease? Or less severe disease?

It’s also too early to know for sure, but another report from the Statens Serum Institut didn’t show a difference in the risk of hospitalizations from BA.2. ............(more)

https://slate.com/technology/2022/01/stealth-omicron-heres-what-we-know-so-far.html