This mutation also known as B.1.617.2, and first discovered in India is making its way westward and is an emerging infection in the US.
The US Centers for Disease Control and Prevention (CDC) has now upgraded the (B.1.617.2) Delta mutation to a classification of a "variant of concern.” It had previously been a “variant of interest.”
The CDC defines a “variant of concern,” as “a variant for which there is evidence of an increase in transmissibility, more severe disease (e.g., increased hospitalizations or deaths), significant reduction in neutralization by antibodies generated during previous infection or vaccination, reduced effectiveness of treatments or vaccines, or diagnostic detection failures.”
Just last week, both CDC and the Biden Administration expressed their concerns of the variant and reinforced the need for COVID-19 vaccination.
“This variant is now identified to be more transmissible than even other hyper transmissible variants like the one from the UK,” CDC Director Rochelle Walensky, MD, said in an interview last week. "We also know that while our vaccines do work against it, they don’t have as much buffer in terms of protection as some of the other wild type strains. So the concern is not just the more transmissibility—and we have seen more virus in the UK where this variant has also emerged—if we have this other variant circulating here it may lead to a more virulent variant such that our vaccines wouldn’t be able to work.”
The Delta variant, which was first identified in India, ravaged that country this year. India reported over 300,000 cases on 1 day alone in May. At one point, the country was losing 3000 people daily to COVID-19.
Since then, the variant has continued to make its way west with it now the dominant strain in the United Kingdom. Thus far, the COVID-19 vaccines appear to be effective against Delta. In a study done by Public Health England, the Pfizer vaccine was 88% effective against symptomatic disease from the variant 2 weeks after the second dose, compared to 93% effectiveness against the B.1.1.7 (UK) variant. For the Astra Zeneca vaccine, it was 60% effective against symptomatic disease from the B.1.617.2 variant compared to 66% effectiveness against the B.1.1.7 variant.