The B.1.617 coronavirus variant first detected in India has been listed as a "variant of interest" by the US Centers for Disease Control and Prevention (CDC). This means that the virus may have mutations that would make the virus more transmissible, cause more severe disease or make the vaccine less effective.

The B.1.617 variant, also referred to as the double mutant, has been implicated in the recent surge in cases in the country, though further analysis is needed to verify this. It is now the most common variant in India and has also been detected in USA, UK and Israel.

The CDC has defined three categories of coronavirus variants:

• Variant of interest
• Variant of concern
• Variant of high consequence

Currently the variants of concern are: B.1.1.7 (variant first identified in the UK), P.1 (variant first identified in Brazil), B.1351 (variant first identified in South Africa) and B.1.427 and B.1.429 (variants first identified in California). 

The CDC defines variant of interests as “a variant with specific genetic markers that have been associated with changes to receptor binding, reduced neutralization by antibodies generated against previous infection or vaccination, reduced efficacy of treatments, potential diagnostic impact, or predicted increase in transmissibility or disease severity”.

“A variant of interest might require one or more appropriate public health actions, including enhanced sequence surveillance, enhanced laboratory characterization, or epidemiological investigations to assess how easily the virus spreads to others, the severity of disease, the efficacy of therapeutics and whether currently authorized vaccines offer protection.”

(Source: CNN, CDC)

Dr KK Aggarwal

President CMAAO, HCFI and Past National President IMA