As the spread of Omicron variant of COVID-19 decreases in the U.S., experts warn about the even more contagious sub-variant of Omicron, known as BA.2.
The new strain has been increasing steadily and has already overtaken the original Omicron variant in South Africa and caused a second surge in Denmark and the U.K., which has the World Health Organisation (WHO) and experts all around the world worried.
WHO has previously warned that Omicron is not mild. “It is less severe than Delta but we are still seeing significant numbers of hospitalizations of Omicron."
WHO also pointed out that all other COVID-19 variants continue to decline globally as Omicron infections increase. Among the more than 400,000 COVID-19 sequences uploaded to the world's biggest virus database in the last week, more than 98 percent of the sequences were Omicron.
Lab studies suggest signs of severity
Lab studies have revealed that the new strain BA.2 could cause severe illness while being more contagious than previously identified COVID-19 variants, including Delta, and it also shows antigenic escape properties on top of being resistant to monoclonal antibodies, such as sotrovimab, according to a preprint study on the bioRxiv, which was published before peer review.
BA.2 strain in the U.S. accounts for an estimated 3.9 percent of all new infections nationally, according to the U.S. Centers for Disease Control and Prevention (CDC). The infections seem to be doubling fast. Experts warn that if the number of infections doubles to 8 percent, another wave of COVID-19 could be experienced in the U.S.
Meanwhile, the CDC is also keeping a close eye on BA.2, according to CNN. Dr. Rochelle Walensky, the director of the CDC, said, "There is no evidence that the BA.2 lineage is more severe than the BA.1 lineage. CDC continues to monitor variants that are circulating both domestically and internationally. We will continue to monitor emerging data on disease severity in humans and findings from papers like this conducted in laboratory settings."
The new strain is on UKHSA’s watchlist
When compared to the original virus that emerged in Wuhan, China, it can be seen that the BA.2 is highly mutated with dozens of gene modifications also distinguishing it from the original Omicron strain. BA.2 is also known as "stealth Omicron" since it does not appear on PCR tests as an S-gene target failure, as Omicron does. To detect this variant, labs must go the extra mile and sequence the virus, which points to the need to establish a special method to detect BA.2 more efficiently.
Incident Director of the U.K. Health Security Agency (UKHSA) Dr. Meera Chand said, "It is the nature of viruses to evolve and mutate, so it's to be expected that we will continue to see new variants emerge as the pandemic goes on".
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