On April 1, the UK health authorities  requested India to send samples of the B.1.617 strain to conduct further research and determine the efficacy of existing vaccines against it.


The World Health Organization designated a coronavirus variant discovered in India as a “global variant of concern” on Monday. Authorities in the United Kingdom classified this variant, known as B.1.617, as a variant under investigation (VUI) earlier this month. It has already spread to more than 17 countries, and as a result of the increase in cases in India, several countries have imposed travel restrictions on passengers arriving from India.

According to the WHO, a variant of interest (VOI) becomes a variant of concern (VOC) if it has been demonstrated through comparative analysis to be associated with an increase in transmissibility or a detrimental change in COVID-19 epidemiology, an increase in virulence or a change in clinical disease presentation, or a decrease in the effectiveness of public health and social measures or available diagnostics. Alternatively, the WHO may classify a variant as a VOC after consulting with the WHO SARS-CoV-2 Virus Evolution Working Group.

The Indian government said last week that this variant, also known as the “double mutant variant,” could be linked to an increase in coronavirus cases in some states. This admission reversed the Centre’s previous position, which stated that the strain had not been identified in enough samples to establish a sufficient link to the current surge. Nonetheless, the government stated that the link had not been “fully established.”

Earlier this month, India’s Health Ministry announced the discovery of a new “double mutant variant” of the coronavirus, in addition to numerous other strains or variants of concern (VOCs) discovered in 18 states across the country. On April 1, the UK health authorities designated B.1.617 as a VUI and requested that India send samples of the B.1.617 strain to conduct further research and determine the efficacy of existing vaccines against it.

Essentially, the virus’s goal is to evolve to the point where it can coexist with humans because it requires a host to survive. This means that while any virus is likely to become less severe as it evolves, it may also acquire mutations that allow it to evade the body’s immune response or become more transmissible.

Because of the large number of people infected by the SARS-CoV-2 virus, it is evolving quickly. High levels of circulation make it easier for the virus to change because it can replicate more quickly.

The virus’s B.1.617 variant has two mutations known as E484Q and L452R. Both are found separately in many other coronavirus variants, but this is the first time they have been reported together in India. The L452R mutation has been discovered in other VOIs, such as B.1.427/B.1.429, which are thought to be more transmissible and may be able to overcome neutralising antibodies. According to the WHO, laboratory studies indicate that samples from individuals who had natural infection may have had reduced neutralisation against variants with the E484Q mutation.

PHE has designated the variants arising from the B.1.617 lineage as Variants Under Investigation (VUI) with a year, month, and number (for example, the three variants first identified in India are VUI-21APR-01, VUI-21APR-02, and VUI-21APR-03). The variants identified in India may be designated Variant of Concern (VOC) by the UK health authority following a risk assessment with the relevant expert committee.

The Centers for Disease Control and Prevention (CDC) in the United States, on the other hand, divides variants into three categories: variant of interest (VOI), variant of concern (VOC), and variant of high consequence. In the United States, the variants B.1.526, B.1.526.1, B.1.525 (previously designated UK1188 and first identified in the United Kingdom), and P.2 (first identified in Brazil) The B.1.1.7, B.1.351, P.1, B.1.427, and B.1.429 variants circulating in the US, on the other hand, are classified as variants of concern.

A VOI is defined by the CDC as “a variant with specific genetic markers that has been associated with changes in receptor binding, decreased neutralisation by antibodies generated against previous infection or vaccination, decreased efficacy of treatments, potential diagnostic impact, or predicted increase in transmissibility or disease severity.” A VOC is defined as “a variant for which there is evidence of increased transmissibility, more severe disease (e.g., increased hospitalizations or deaths), significant reduction in neutralisation by antibodies generated during previous infection or vaccination, reduced effectiveness of treatments or vaccines, or diagnostic detection failures.”