People who have previously beaten Covid are now more likely to be reinfected because of the Indian variant, an official report has found.
Public Health England said the risk was 46 per cent higher with the Delta variant compared to the previously dominant Kent 'Alpha' variant.
The finding was based on real-world analysis of the third wave in England and looked at about 80,000 Delta cases.
But even with the increased risk posed by the mutant strain, the numbers of Britons getting reinfected still remains low.
Of the Delta cases PHE analysed over the past three months, just 1.2 per cent were identified as possible reinfections.
The results follow a lab study earlier this month which found the variant was able to dodge antibodies from previous infection better than earlier strains.
PHE said the reinfection risk was incredibly low in people who had recovered from Covid in the past six months.
There were more possible reinfections at the height of the second wave, which may be due to the fact the vaccine rollout had not got up and running and the fact the Kent variant was far more transmissible than the earlier version of the virus. But PHE says the risk is still higher with the Indian variant which was seeded in the UK in April
The agency looked at the PCR test results for a group of people, both vaccinated and unvaccinated, who had a positive Covid test at least 90 days earlier.
There were 83,197 people who tested positive in the 11-week period of the analysis, of whom 980 were possible reinfections.
Comparing the results to the second wave, it said the risk of being reinfected with Delta was 46 per cent higher than Alpha. The analysis adjusted for different variables including age and vaccination.
