Pfizer vaccine ‘protective for at least six months’

Results of the new study were posted online but have not undergone full scientific review

File Picture: Danny Lawson/PA

The effectiveness of the Pfizer vaccine wanes slightly over time but it remains strongly protective for at least six months after the second dose, according to company data.

The findings are one piece of evidence that US health authorities will consider in deciding if and when booster doses might be needed.