Women are more likely than men to experience adverse reactions after getting the flu shot, such as fever, headache and arm discomfort.
The study, which looked at more than 34,000 people in 18 scientific studies focusing on responses to flu vaccination, suggests side effects are more common in women. Women, especially those over 65, are more susceptible to this effect, with a 43% increased likelihood of arm problems (such as pain or swelling) and a 27% increased likelihood of systemic reactions (such as fever, muscle aches) or headaches, all of which are more common in women than men.
Additionally, women under the age of 65 are also more likely to experience side effects from the flu vaccine. This includes younger groups, such as pregnant women and people with special health conditions, who are being vaccinated as part of the NHS winter programme.
Dr. Marilou Kiely, who led the study at the University of Montreal, stressed that reactions to the flu vaccine are more common in women across age groups, regardless of which vaccine is given. However, as individuals age, the likelihood of these reactions decreases in both men and women.
It’s important to note that reactions to these vaccines in women are usually mild and tend to improve on their own. Dr. Keeley also stressed the importance of considering the potential benefits of the flu vaccine, especially for vulnerable groups such as older adults and people with certain medical conditions.
The study, published in the Journal of Epidemiology and Community Health, showed arm pain was the most common problem after getting the flu shot, while muscle pain and headaches were the most common reactions throughout the body. The researchers said these systemic reactions were relatively less likely to occur in women, affecting only 74 women per 1,000 people vaccinated. However, women may be more likely to experience reactions that disrupt daily activities.
Women over 65 were 51% more likely than men to have more serious arm problems that temporarily interfere with daily tasks. They were also 48% more likely to experience severe systemic reactions, such as muscle pain and fever, that could affect their daily lives. However, differences in severe systemic reactions were less pronounced between women and men over 65 years of age compared with younger adults, which may indicate that older women’s immune systems are less responsive to influenza vaccines.
It should be noted that, in general, older people tend to have weaker vaccine responses. The analysis, which covered studies conducted between 2010 and 2018, found that women responded more to the flu vaccine than men, regardless of whether they received the trivalent or quadrivalent vaccine (which protects against three or four flu viruses).
The researchers acknowledge that women are generally more likely to report and seek help for health problems based on previous evidence, which may result in women being considered to be at higher risk for flu vaccine reactions than men. Furthermore, the quality of evidence from the studies reviewed was rated as moderate at best, underscoring the need for further research.
More than 2.8 million people in England have been vaccinated against influenza since the autumn booster vaccination campaign began on September 11, according to NHS England.