1/BREAKING on #SARS_CoV_2 variants: the emerging variants in South Africa and Brazil that harbor the E484K mutation have "greatly reduced susceptibility" to neutralization by polyclonal serum antibodies derived from some individuals. This may have consequences for vaccines

2/The "Receptor Binding Domain" on the Spike protein of the virus is a critical site for antibodies to bind to because those antibodies can block the virus from binding the ACE2 receptor on our cells. Mutations at that site are allowing the virus to escape antibodies.

3/Report shows neutralizing activity of convalescent sera (rich in polyclonal antibodies) was reduced >10-fold because of single mutation in RBD domain. They also found some sera samples that still neutralized, perhaps through antibodies binding other critical regions of spike.

4/This is worrying but the fact that neutralizing function was diminished, not eliminated, suggests a strong vaccine response will protect against the variant. However, failure to control the pandemic gives the virus more opportunities to evade vaccines. https://www.biorxiv.org/content/10.1101/2020.12.31.425021v1