@l_i_i_i_i_i @erictopol "moreover, b.1.351 is markedly more resistant to neutralization by convalescent plasma (9.4 x) &amp; vaccinee sera (10.3-12.4 x). b.1.351 &amp; emergent variants13,14 w/similar spike mutations present new challenges for mab therapy &amp; threaten the protective efficacy of current vaccines."