The US Centers for Disease Control and Prevention has reclassified the Delta strain of Covid-19 as a variant of concern, based on “mounting evidence” of it being more transmissible, the media reported.
The CDC’s classifications define three classes of variants of COVID-19 — variants of interest, variants of concern, and variants of high consequence.
Other variants, circulating in the US, classified by CDC as variants of concern include the B117 (Alpha), B1351 (Beta), P1 (Gamma), B1427 (Epsilon), B1429 (Epsilon), and B16172 (Delta).
“CDC and SARS-CoV-2 Interagency Group continually review the available scientific evidence and the genomic surveillance data to assess the classification of variants,” Fox news quoted the CDC as saying.
According to the CDC, a variant’s classification status can change as officials learn more about them.
The Delta variant, which was first detected in India, has spread to at least 66 countries including the US, the CDC said on Tuesday.
Earlier this week, UK health officials said that two doses of the BioNTech/Pfizer vaccine were 96 per cent effective against hospitalisation from the Delta variant.
According to new data, Delta now makes up about 10 per cent of US cases, up from just one per cent less than a month ago.
The variant is likely to become the dominant source of new infections in the US and could lead to new outbreaks by September, said Scott Gottlieb, the former commissioner of the US Food and Drug Administration, recently.
“Right now, in the United States, it’s about 10 per cent of infections. It’s doubling every two weeks,” Gottlieb was quoted as saying on CBS’ Face the Nation on Sunday.
However, Gottlieb also noted that the mRNA Covid-19 vaccines approved for use in the US appear to be effective at containing the Delta variant, highlighting the importance of the public vaccination campaign.
“The mRNA vaccine seems to be highly effective, two doses of that vaccine against this variant. The viral vector vaccines from J&J and AstraZeneca also appear to be effective, about 60 per cent effective. The mRNA vaccines are about 88 per cent effective,” he said, referring to the vaccines developed by Moderna and Pfizer/BioNTech.