A British public health study has found that protection from either of the two most commonly used Covid-19 vaccines against the now prevalent Delta variant of the coronavirus weakens within three months, Reuters reports.
The Oxford University study found that 90 days after a second shot of the Pfizer or Astrazeneca vaccine, their efficacy in preventing infections had slipped to 75 per cent and 61pc respectively. The decline in efficacy was more pronounced among those aged 35 years and older than those below that age.
