Public Health England estimate of vax effectiveness against B.1.617.2 variant: they're not reporting vaxes separately yet. Combined data: 1 dose doesn't reach minimum effectiveness level; 2 doses it's reduced, but still high...1/2 HT @statsepi @kallmemeg assets.publishing.service.gov.uk/government/upl… 
...They have moderate degree of certainty in conclusion from data on 1 dose, low for 2-dose. Based on the neutralization activity they see in lab tests, "expected to remain effective against severe disease". They don't say when data will be released. 2/2 assets.publishing.service.gov.uk/government/upl…
...PS: From Public Health England preprint on vax effectiveness against B.1.617.2 variant of concern, includes data on "UK" & the new variant. Based on results of 12,675: 11,621 with B.1.1.7 & 1,054 had B.1.617.2...3/n khub.net/documents/1359… HT @dylanhmorris
...2 methods of analysis: test-negative case-control & proportion of cases per variant by vax status (with the assumption if vax less effective, that variant would be a higher proportion of cases in the vaxed than the unvaxed)...4/n
...From the test-negative case-control study:
B.1.1.7 ("UK" variant now dominant there):
- 1 dose: BNT-Pfizer 49.2% (43-55), AZ 51.4% (47-55)
B.1.617.2:
- 1 dose: BNT-Pfizer 33.2% (8-51), AZ 32.9% (19-44)
...5/n
B.1.1.7 ("UK" variant now dominant there):
- 1 dose: BNT-Pfizer 49.2% (43-55), AZ 51.4% (47-55)
B.1.617.2:
- 1 dose: BNT-Pfizer 33.2% (8-51), AZ 32.9% (19-44)
...5/n
... B.1.1.7 (dominant variant there):
- 2 doses: BNT-Pfizer 93.4% (90-96), AZ 66.1% (54-75)
B.1.617.2:
- 2 doses: BNT-Pfizer 87.9% (78-93), AZ 59.8% (29-77)
Interval between doses not reported. Lots of uncertainty for 2-dose AZ & new variant
(Corrected TY @dylanhmorris)
.6/n
- 2 doses: BNT-Pfizer 93.4% (90-96), AZ 66.1% (54-75)
B.1.617.2:
- 2 doses: BNT-Pfizer 87.9% (78-93), AZ 59.8% (29-77)
Interval between doses not reported. Lots of uncertainty for 2-dose AZ & new variant
(Corrected TY @dylanhmorris)
.6/n
...The conclusion from the second method of analysis: "By vaccine type the reduction in vaccine effectiveness appeared to be greater with ChAdOx1 (OR 1.48; 95%CI 1.18-1.87) than BNT162b2 (OR 1.17; 95%CI 0.82-1.67) though confidence intervals overlapped"... 7/n
...They conclude "Nevertheless, a clear effect of both vaccines was noted with high levels of effectiveness after two doses". But the lower bound of the confidence interval for AZ 2 doses slips just below the 30% minimum set for effectiveness, so I wouldn't call that high... 8/9
...From the preprint, it turns out previous conclusion based on neutralization data isn't data from them or for either of these vaxes - they only had the Covaxin study. (I think the general experience of effectiveness being greater against severe outcomes is more compelling.) 9/9
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