Research Says More Women Than Men Have Vaccine Side Effects It seems that even with COVID-19 vaccines, women can't catch a break. New research indicates that women experience side effects from the COVID-19 vaccine more than men, according to a report from Western Mass News. The study, conducted by the Centers for Disease Control and Prevention, shows that women are reporting more adverse reactions from the vaccine shot than men, but it seems to be simply the result of their bodies’ immune response. According to the CDC, after looking at the first month and almost 14 million vaccinations, 79.1% of the reports of more severe side effects came from females.