Severely overweight healthcare workers generated only half the antibodies to fend off Covid after receiving two doses of the jab, compared to healthy people.

Italian researchers said obese people may need another top-up vaccine, or bigger doses, to protect them against the disease…

Scientists say this may be because they are more likely to have other conditions —such as diabetes and high blood pressure — that make them more vulnerable.

Experts today said it was also well known obesity — defined as having a BMI above 30 — hampers the effectiveness of jabs.