People who have had the Pfizer-BioNTech jab have lower antibody levels against the Indian Covid variant than those against other strains in the UK, new data suggests.
The study also indicates that the level of antibodies against the strain lowers with increasing age and that they decline over time.
Researchers said this highlights the need for a vaccination booster programme for vulnerable people in the autumn.
The new lab data from the Francis Crick Institute and the National Institute for Health Research (NIHR) UCLH Biomedical Research Centre also supports current plans to reduce the dose gap between vaccines.
People who have one Pfizer dose are less likely to develop antibody levels against the Indian – Delta – variant that are as high as those seen for the Kent – Alpha – variant.