Health experts explained why women report more side effects after receiving the COVID-19 vaccine than men.
Women Reports More Side Effects
From December 14 to January 13, almost 7,000 cases were processed through the Centers for Disease Control and Prevention's Vaccine Adverse Effect Reporting System, with more than 79 percent of them coming from women. Headache, nausea, and dizziness were the most often recorded side effects.
Women are much more likely than men to suffer some of the vaccine's more unusual side effects, such as an itchy red rash at the injection site known as the COVID arm or Moderna arm, since the Moderna vaccine accounts for about 95 percent of the reactions. Women account for 77 percent of the confirmed side effects of the Moderna vaccine, according to a published article in The USA Today.
Biological Differences Between Men and Women
According to doctors, women have a stronger immune response to vaccines than men, which may explain why more of them have documented side effects from the COVID-19 vaccine. This also includes inconsistent reporting by men and gender disparity in clinical trials.
Rosemary Morgan, a research scientist at Johns Hopkins Bloomberg School of Public Health, said, "From a biological perspective, women and girls produce sometimes twice as many infection-fighting antibodies from vaccines."
In a recently published article in Yahoo News, while there is no evidence comparing men's and women's immune responses to the COVID-19 vaccine, researchers from a 2019 study discovered that women had higher cytokine and antibody responses after receiving the flu vaccine than men.
Dr. Daniel Saban, an immunologist scientist at Duke University School of Medicine, also said hormones could also affect immune responses in men and women, according to Saban, since certain immune cells contain estrogen receptors. Women develop more estrogen than males, which can influence how immune cells function.
Health experts said that women might be experiencing more side effects because men are more unlikely to report their COVID-19 side effects.
Morgan said, "We don't have more robust evidence that looks at reporting side effects, but what we do know is that it is possible that women may be reporting more side effects than men due to what we know about how men behave in relation to health care."
According to the World Health Organization, studies have found that women are more likely than men to use health care facilities. This may explain why men may underreport COVID-19 vaccine side effects.
Morgan claims that clinical testing has traditionally ignored sex disparities, which have changed how women respond to licensed vaccines and drugs. Women were largely removed from clinical trials until the National Institutes of Health Revitalization Act of 1993, which mandated the participation of minorities in clinical studies.
Even though women were involved in the COVID-19 vaccine clinical trials, health researchers believe gender inequality persists today. Unlike pediatric patients, who are normally dosed based on weight, an adult man and woman receive the exact dosage of vaccine regardless of age.