Vaccine experts call for clarity on UK's 12-week Covid jab interval

British Society for Immunology calls for a robust programme monitoring the body's immune response

Experts have called for greater clarity on the monitoring in place to assess the 12-week dosing interval for Covid-19 vaccines, as the row over delayed second doses continues.

The UK's coronavirus vaccination programme was shifted late last year to prioritise administering the first dose to as many at-risk people as possible. As a result, the interval between the two doses was increased to up to 12 weeks.