Omicron’s BA.2 sub-variant remains the dominant strain in the United States. (Photo AFP)
Omicron’s BA.2 sub-variant, which has produced more mutants, is gaining ground in the United States, according to Centers for Disease Control (CDC). The health agency added that while BA.2 remains the dominant variant in the US, BA.2.12.1 now accounts for about a fifth of new cases nationwide.
At least 21 viruses of BA.2 have been reported globally, CNN reported. But except for BA.2.12.1, the others had less significant mutations.
CDC data shows that BA.2.12.1 caused 19% of new cases in the US last week, up from 11% a week earlier and 7% a week earlier.
How fast does the new sub-variant go viral?
According to the CDC, BA.2 and BA.2.12.1 accounted for about 93% of new COVID-19 cases last week in the US.
The seven-day moving average of US COVID cases stood at 34,972 as of April 16, up 23.4% from a week earlier.
Overall cases have fallen sharply across the United States since hitting a record in January, but COVID-19 infections have increased over the past few weeks, particularly in Northeast states like New York and Connecticut.
NBC reported that the latest variant was 23 to 27% more transmittable than BA.2. However, there is currently no evidence that BA.2.12.1 causes more severe illness, the report added.
A resurgence of COVID-19 cases in parts of Asia and Europe has raised fears that another wave could follow in the US.
What distinguishes BA.2.12.1 from BA.2?
According to Trevor Bedford, an epidemiologist and genomic scientist at the University of Washington School of Public Health, B.2.12.1 has the mutant mutation S704L and L452Q on the background of BA.2.
Here, what is to be seen based on the mutation alone is that B.2.12.1 has the spike mutation S704L and L452Q on the background of BA.2. In the past, L452R appears to have played an important role in driving the spread of Delta and has also appeared in Epsilon and Lambda. 6/17
– Trevor Bedford (@trvrb) April 18, 2022
He added on Twitter that in the past, the L452R appears to have played a key role in driving the spread of Delta and has also appeared in Epsilon and Lambda.
“We observed a logistic growth rate of 0.06 per day in NY (New York) and 0.11 per day in MA (Massachusetts). This is similar to the observed advantage of BA.2 over BA.1,,” he said in another tweet.
Warning about new sublines of Omicron
The New York State Department of Health warned city residents last week about the new substreams, warning that they are spreading about 25% faster than BA.2 and are causing cases of Covid-19 and increased hospitalizations.
It also urged New Yorkers to “act quickly” to consider wearing masks, getting a booster dose of the vaccine, testing if they have symptoms and seeking treatment if infected.
