Thread by @DrEricDing

BREAKING—Novavax says its #COVID19 vaccine is 90% effective, but likely only 50% against the #B1351 variant found in South Africa.

50% better than 0%, but clearly we have challenges with the #B1351 mutation. UPDATES COMING.
nytimes.com/2021/01/28/hea…

2) SURPRISING—“Participants were infected with the variant even after they had already had Covid.” This aligns with what South Africa CDC warned last week

3) “we are the first to conduct an efficacy trial — in the face of a changing virus,” said Stanley Erck, CEO of Novavax. He said that researchers expected variants could change the trial results, but “the amount of change has been a bit of a surprise to everyone.”

4) “South Africa trial was relatively small — with just 4,400 volunteers — and was not designed to come up with a precise estimate of how much protection the vaccine provides...

5) “Still, the results were striking enough that the company said it would soon begin testing a new vaccine tailored to protect against the variant from South Africa. “You’re going to have to make new vaccines,” Mr. Erck said.”

6) Moderna also recently tested the #B1351 and also noted significant drop in neutralization in a lab study. But their press release somewhat downplayed it unless you read it carefully. They did not have efficacy data though.

https://twitter.com/drericding/status/1353706396282474499

7) Moderna’s press release was cautiously worded—“6-fold reduction in neutralizing titers was observed with B.1.351 variant relative to prior variants. Despite reduction, neutralizing titer levels w/ B.1.351 remain above levels expected to be protective.” investors.modernatx.com/news-releases/…

8) most worrisome was the recent #b1351 variant data that blood from 48% of people previously recovered from #COVID19 in the 1st 2020 wave in South Africa 🇿🇦 did not recognize the new #B1351 variant — “complete immune escape”. 90% had lower neutralization.

https://twitter.com/drericding/status/1351282325926146048?s=21

9) As pointed out by Dr Andersen, this doesn’t change our need to vaccinate as fast as possible, even with some ~50% immunity.

https://twitter.com/k_g_andersen/status/1351278058544668672

10) Worrisome—First two community transmission cases of the vaccine evading #SARSCoV2 strain #B1351 first seen in South Africa 🇿🇦 have been detected in South Carolina. No travel history in either cases. #B1352 is the one seen to evade antibodies. #COVID19 amp.cnn.com/cnn/2021/01/28…

11) Psssst... vaccines are still good. They will work.

Wanna know something that works well too against all virus strains? #ZeroCovid strategy.

https://twitter.com/DrEricDing/status/1353979907072806912

12) We knew something like this drop in vaccine efficacy for the #b1351 strain was coming when we saw South Africa 🇿🇦 CDC made this sobering declaring on reinfection among those with previous immunity & 50% who had no neutralizing activity despite antibodies. Early signals key.

https://twitter.com/DrEricDing/status/1351686170044989442

13) while the vaccine was 49 percent effective in South Africa, Novavax underscored that when looking only at people not infected with HIV, the efficacy was 60 percent. Better but much lower than 89% in UK (where half got #b117). washingtonpost.com/health/2021/01…

14) But if the average in SA is 49%, and HIV negative people had 60% efficacy, then we know HIV positive cases must be much below 49%. Unclear if this HIV difference is significant modifier of the vaccine or just due to chance.