Thread by @BalazsLab

We have just uploaded a pre-print to MedRxiv sharing our data on the potential for sera from recipients of currently administered mRNA vaccines to neutralize 10 different circulating strains of #SARSCoV2. Before it posts online, I'd like to put them into context. A thread:
1/12

Here's a key graph from our pre-print showing the results of our neutralization assay on sera taken from vaccinees receiving two or one dose of BNT162b2.
2/12

First off, we find (as other have reported) that several strains are neutralized as well as the D614G variant. These include strains such as B.1.1.7 (first described in the UK) and B.1.429 (first described in California, USA).
3/12

However, we find that B.1.1.298 (sometimes referred to as the Mink variant) has a small degree of resistance to vaccinee sera. More worrisome are the P.1 and P.2 variants (first described in Brazil/Japan) which in our hands showed substantial resistance.
4/12

Of greatest concern, we find that three different variants of B.1.351 show very significant resistance to neutralization by vaccinee sera. About half of our samples exhibited potency below the limit of our assay. They were even less neutralized than SARS-CoV or WIV1-CoV.
5/12

So what does this mean?

First, off, let me be very clear that our findings need to be replicated by other groups. This is a pre-print and has not yet undergone peer review. We might be missing something important that other scientists will point out to us.
6/12

However, @sigallab saw similar results with live 501Y.V2 (B.1.351) strains against convalescent plasma in the BSL-3 (medrxiv.org/content/10.110…).
7/12

Penny Moore also reported similar findings using pseudovirus assays performed with convalescent plasma from recovered patients (biorxiv.org/content/10.110…).
8/12

Even if this is all correct, it doesn't mean that vaccines won't keep us safe. There is a lot more going on than just serum neutralization when you get vaccinated. It's entirely plausible that the existing vaccines will keep us from developing severe #COVID19.
9/12

What you should take away from this work is that we need to remain vigilant when it comes to SARS-CoV-2 evolution and that vaccine developers should be on the lookout for mutations that might lead to escape. We should also increase genomic surveillance efforts worldwide!
10/12

Many thanks to @wilfredo_nk @EvanCLam @kstdenis29 @NaranbhaiVivek @adamnitido and Zeidy Garcia who have been sleeping very little and working very hard over the past few weeks to generate all of this data.
11/12

I also want to be sure to thank all of our amazing collaborators at @MGHPathology and @ragoninstitute including @blakemhauser, Jared Feldman and of course the entire @SchmidtLabHMS!
12/12