Thread by @BijayaKDhakal

Since India announced the ‘E484Q & L452R’ #DoubleMutant , I was curious about the emergence of the ‘E484Q and L452R’ mutations. When I analyzed all publicly available #SARSCoV2 sequences, the first ever case was reported in Maharashtra, India in a sample collected on 12/5/2020.

In India, the Double Mutants are primarily found in Lineage B.1; USA- B.1.427 and B.1.429; Sweden-L.3. Outside of India only 46 sequences of double mutant were found, UK-22, USA-12 (mostly California), Sweden-5, Canada -3, 1 in Singapore, Germany, Australia and New Zealand each.

The E484Q mutation was first seen in a sample collected on 03/09/2020 in Midtjylland, Denmark; 03/20/2020 in San Diego, US; 03/22/2020 in Maharashtra, India; 5/20/2020 Wales, UK. The mutation is seen mostly in B.1 lineages including B.1.1.7 and mostly in India, USA and UK.

Outside of India the E484Q mutation is seen only in 217 sequences. India has not publicly shared all the sequences. The functional significance of E484Q mutation is untested at this point but the E484K substitution on the same amino acid is present in 🇿🇦 B.1.351 & 🇧🇷P.1 lineages.

The E484K impacts neutralization by monoclonal antibody (MAB) therapeutics and also convalescent and post-vaccination sera. The South African B.1.351 is ~50% more transmissible

he L452R mutation was first identified in California & believed to be behind the last surge. The L452R variants have ~20% increased transmissibility & greatly impacts neutralization by some MAB therapeutics, and convalescent & post-vaccination sera, though moderately.

The L452R variant in California was first reported on 3/10/2020 but only became the dominant strain at the end of 2020. L452R mutation (B.1.427/B.1.429) along with B.1.1.7, B.1.351 and P.1 are classified as a Variant of Concern by CDC.
cdc.gov/coronavirus/20…

The E484Q and L452R double mutant could be immune escape variants with increased infectivity. The impact of the variant on Astrazeneca vaccine could be grave as the efficacy of this vaccine in South Africa was pretty dismal against the B.1.351 variant.

India is only sequencing about 0.5% of positive cases so far and that is only in the last 3 months. There aren’t many sequences available from Nepal’s neighboring states, UP, Bihar etc. so not much is known about the strains circulating in these states.

There is a significant risk of importing #SARSCoV2 variants to #Nepal from #India. Recent evidence suggests the #doublemutant #indianvariant variant is in play in West Bengal, very close to Nepal.

https://twitter.com/BijayaKDhakal/status/1374948529219768326?s=20