Thread by @john_actuary

The latest Vaccine Surveillance Report now extends efficacy data out to 15 weeks, and shows a continued fall in booster efficacy against symptomatic disease, particularly where AZ was the primary course (below).
assets.publishing.service.gov.uk/government/upl…
1/

mRNA throughout the course and booster appears a smidge better, particularly where Moderna was used for the booster, (although Moderna data doesn't extend to 15+ weeks yet).

2/

Efficacy against hospitalisation where AZ is the primary course dips to below 80% in the 10-14 week period, against 90% at the outset (ie the efficacy gap has doubled over that period).

3/

For hospitalisation there appears little difference where mRNA vaccines were used for the primary course as opposed to AZ.

4/

Bear in mind that these efficacy figures are relative to unvaccinated individuals. As Omicron appears inherently milder than Delta, the difference in overall risk is unlikely to be as stark as the Omicron points appear in comparison to the Delta ones.

5/

Note also that the oldest data (ie W15+) will be predominately in respect of the oldest and most vulnerable, which may influence the apparent trend. However, they still show the relatively low efficacy of that cohort beyond week 15.
6/

I'm sure these results will be used as part of the consideration as to whether to offer a 4th jab for the oldest and most vulnerable. Meanwhile, a shout out to the fantastic team at UKHSA for continuing to deliver such prompt and insightful data.

7/7