The Pfizer vaccine is based on the injection of a nucleic acid (mRNA) that encodes one of the viral proteins. The aim is to stimulate the production of antibodies against the virus and to protect the recipient against disease.
Vaccination is sometimes accompanied by side effects, manifesting, such as pain at the injection site or the entire arm, fever, weakness, fatigue, and paresthesias in different parts of the body.
The researchers examined differences between men and women in reported adverse events following Pfizer vaccination in Israel.
The study was based on data collection from four different sources: reports forwarded to the Department of Health regarding adverse events in people over 16 years of age between December 2019 and June 2021 ; a survey of 923 participants over the age of 30 conducted in June 2021; and two additional surveys with 560 participants aged 20 to 65 years conducted in the workplace in September 2021.
The results of the study showed that the reporting of adverse events after the first, second and third vaccination was about 1.9 times higher in women than in men.
The highest frequency of adverse events reported among all participants were those after the second vaccination. Side effects are usually mild, and include pain at the injection site, fever, headache, weakness, and paresthesias in the arm.
Analysis of study results showed that the percentage of women with total arm pain after vaccination was 7 times higher than that of men after the first vaccination and 4.2 times higher than that of men after the vaccination. during the second vaccination; The rate of women experiencing this side effect after the 3rd vaccination was 4.1 times higher than that of men.
The proportion of women reporting weakness was 30 times higher than men after the first dose, 2.6 times higher after the second dose and 1.6 times higher after the third dose.
Women were 9 times more likely to experience headaches than men after the first dose, 3.2 times more after the second dose, and 2.45 times higher after the third dose. The results of the study highlight the need to report vaccine side effects separated by sex.