New data has revealed that the estimates used to justify the delay to the end of lockdown may have been unduly pessimistic because vaccines work better than expected.

The projections presented this week to SAGE, the government’s science advisory body, outlined a range of scenarios in which a double dose of the AstraZeneca vaccine was assumed to provide between 85 and 90 per cent protection against severe disease from the Delta variant. For two Pfizer doses, the estimate was 87 to 91 per cent.