Women are twice as likely to suffer a “severe” reaction to the flu jab as men, a new study has revealed.
Analysis of 34,000 adults who received the flu vaccination between 2010 and 2018 found that 3 per cent of women had a severe reaction, compared to just 1.5 per cent of men.
Researchers from the University of Montreal, Canada, classified severe reactions as symptoms such as high fevers over 39 degrees, or significant swelling, pain or rashes known as erythema, that led to people being unable to carry out daily tasks.
The study, published in the Journal of Epidemiology and Community Health, found that women were also around a third more likely to suffer from other, less serious side effects than men.
It said that 38.6 per cent of the 20,295 women analysed had suffered side effects like headaches, vomiting, fevers and muscle aches after their vaccination, known as “systemic reactions”, compared with just 28.6 per cent of the 13,860 men - around 29 per cent fewer on the whole.
The study said for every 1,000 people getting the flu vaccine, 74 more women would have these side effects than men.
Researchers also found that women were 31 per cent more likely to get pain, swelling or an infection around the injection site.
It said this happened to 44.6 per cent of women and 33.9 per cent of men.
Dr Marilou Kiely, author of the report, said while “most reactions are mild, self-limited and rarely serious”, a bad reaction could “be a barrier” to having another vaccination.
“Transparent communication regarding the increased risk for females would potentially help sustain long-term trust in health authorities and vaccines,” she said.
Dr Conall Watson, a consultant epidemiologist at the UK Health Security Agency (UKHSA), said that “serious side effects are rare following a flu jab”.
‘Hospitalisation and death’
“Flu can cause very serious illness, hospitalisation and death,” he said. “Some people are more susceptible to the effects of flu - flu can trigger heart attacks, or lead to pneumonia, and can make existing medical conditions worse.”
The NHS stresses that “severe allergic reactions” like anaphylaxis are very rare at around one in one million and that some of the reactions categorised as severe in this study, such as erythema, usually resolve on their own, even if they are uncomfortable.
The NHS has administered 2.8 million annual flu vaccines since the programme launched earlier this month.
More than 30 million people in England are eligible for a free flu vaccination this winter, although 50 to 64-year-olds will not be able to this time in a return to the pre-pandemic offer.
“I would strongly encourage any woman or man eligible for a flu jab to come forward to reduce their risk of serious illness this winter,” Dr Watson said.