Jan 26 - New Stealth Omicron variant has arrived in United States. Getvaxd
It’s really time to just take the vaccine smh
The original omicron carries a "deletion" in the gene that codes for its spike protein, which the virus uses to infect cells. PCR tests for SARS-CoV-2 scan for several genes, including the spike protein gene, and when a variant carries this deletion, the PCR test displays an error that reads "S gene target failure." This error makes it easy to flag likely omicron cases and then run the samples
The BA.2 sublineage, however, does not carry this deletion, known as 69-70del, so it doesn't stand out on PCR tests from other variants that lack the deletion. A person with BA.2 will still test positive for the coronavirus on a PCR test, but their case won't be flagged as BA.2 unless their original sample goes through genetic sequencing.
"Don't get the impression that 'stealth omicron' means we can't detect it," Dr. S. Wesley Long, a pathologist at Houston Methodist in Texas, told The a*sociated Press (AP).
So far, stealth omicron has been detected in 40 countries, including the U.S., according to the AP. In general, BA.2 currently appears more common in Asia and Europe than on other continents.
The U.K. Health Security Agency has designated BA.2 as a "variant under investigation," in light of the country's rising number of BA.2 cases, although BA.1 remains dominant overall. In Denmark, the variant was responsible for 45% of COVID-19 cases in mid-January, up from 20% at the beginning of the month, the AP reported. And as of Monday (Jan. 24), BA.2 accounted for 65% of Denmark's new coronavirus cases, Anders Fomsgaard, a virologist at the State Serum Institute in Denmark, told The Washington Post. Overall, coronavirus cases are still increasing in Denmark.
In the U.S., BA.2 does not make up a similarly high proportion of coronavirus cases as seen in the U.K. and Denmark, James Musser, director of the Center for Molecular and Translational Human Infectious Diseases Research at Houston Methodist, told The Washington Post. Houston Methodist recently identified three BA.2 cases, but as of now, the sublineage hasn't gained much ground in the U.S., Long told the AP. The mutant has also been spotted in Connecticut and California, among other states, according to news reports.
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