Observational study finds a single dose of either Pfizer-BioNTech and Oxford-AstraZeneca vaccines in older adults is about 80% effective at preventing admission to hospital with covid-19.

Effectiveness of the Pfizer-BioNTech and Oxford-AstraZeneca vaccines on covid-19 related symptoms, hospital admissions, and mortality in older adults in England: test negative case-control study – The BMJ

Editorial: Effectiveness of England’s initial vaccine roll out – The BMJ