Given the dire situation in India and questions regarding the new variant B.1.617, the so called ‘Double Mutant’ we are sharing some prelim analyses on viruses with either or both of the mutations E484Q and L452R in the critical receptor binding domain that our antibodies target

One key question is whether these mutations together are able to overcome immunity from vaccines and natural immunity from past infections. We tested serum from 9 young individuals (<50 years old) who had one dose of the Pfizer vaccine 4-12 weeks prior to the blood sample.

E484K seen in B.1.351 and P.1 (ex SA and Brazil), gives around a ten fold loss of neutralisation. B.1.617 has E484Q which has not been studied. E484Q has a smaller, 6 fold loss. The second mutation, L452 has a 4 fold effect(not statistically different to Wuhan-1 D614G here).

Here is the REALLY IMPORTANT part. The combination of the two mutations gives a value of 4, in other words the two mutations DO NOT confer substantial antibody evasion and we can stop using the term 'Double Mutant'.

This is reassuring and gives us good reason to believe that expanding vaccination in India will contribute to control of transmission as well as the severe effects of COVID-19. The data also help to explain why one significant sub lineage of B.1.617 appears to have lost E484Q.

Please note that the B.1.617 may still be more transmissible as our data along with others suggest L452R increases the ability of the spike to gain entry into cells.We will preprint with greater numbers soon @isabella_atmf @CambridgeBRC @rpdatir