Our new preprint on the efficacy of a single dose of the Oxford/AZ ChAdOx1 nCoV-19 #vaccine-76% efficacy against symptomatic infection from day 22 to day 90 post vaccination in 17,177 trial participants in UK, Brazil and S Africa:
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3777268

VE against symptomatic COVID-19 clearly higher with longer interval between first and second dose

Clear relationship between binding and neutralising antibody response at 28 days post dose 2 and vaccine efficacy (VE) with 12+ week interval given strongest antibodies and higher VE

No-one in a population of 12,408 people vaccinated with a single dose of ChAdOx1 nCo-19 was hospitalised with COVID-19 from 22 days after immunisation. This is the most important thing! 76% efficacy against symptomatic COVID-19 is great, but 0 people hospitalised is everything.

Finally, reduction in any PCR+ (symptomatic or asymptomatic) of 54% after 2 doses, indicating the potential for reducing transmission. Overall, the Oxford/AZ vaccine has 76% efficacy against symptomatic COVID19 infection, prevents hospitalisation and reduces transmission!

#VaccinesWork (but also still please stay at home, wear a mask, social distance, wash your hands and be nice to each other)!