Despite claims by anti-vaccine activists no different than groups that used to claim vaccines cause autism, COVID-19 vaccines do not affect fertility — the likelihood of conception per menstrual cycle — in female or male partners who received the Pfizer-BioNTech, Moderna or Johnson & Johnson vaccines.
The prospective study instead indicates that COVID-19 infection among men may temporarily reduce fertility – an outcome that can be avoided through vaccination.
Lead author Dr. Amelia Wesselink, an epidemiologist at the Boston University School of Public Health, and colleagues analyzed survey data on COVID-19 vaccination and infection, and fertility, among female and male participants in the BUSPH-based Pregnancy Study Online (PRESTO), an ongoing NIH-funded study enrolling women trying to conceive up to six months postpartum. Participants included 2,126 women in the United States and Canada who provided information on sociodemographics, lifestyle, medical factors, and characteristics of their partners from December 2020 to September 2021, and participants were followed in the study until November 2021.
The researchers calculated the probability of conception per menstrual cycle using self-reported dates of the participants’ last period, typical menstrual cycle length and pregnancy status. Fertility rates among female participants who received at least one dose of a vaccine were nearly identical to unvaccinated female participants. Fertility was also similar for male partners who had received at least one dose of a covid-19 vaccine compared to unvaccinated male participants. Further analyzes that considered the number of vaccine doses, vaccine brand, history of infertility, occupation and geographic region also indicated no effect of vaccination on fertility.
While COVID-19 infection was not strongly associated with fertility, men who tested positive for COVID within 60 days of a given cycle had reduced fertility compared to men who never tested positive, or men who tested positive at least 60 days prior. These data support previous research that has linked COVID-19 infection in men with poor sperm quality and other reproductive dysfunction.
“These data provide reassuring evidence that covid vaccination in either partner does not affect fertility among couples trying to conceive,” said senior author Dr. Lauren Wise, professor of epidemiology at BUSPH. “The prospective study design, large sample size, and geographically heterogeneous study population are study strengths, as was our control for many variables such as age, socioeconomic status, preexisting health conditions, occupation, and stress levels.”
The new data also help quell concerns about COVID-19 vaccines and fertility that arose from anecdotal reports of women experiencing menstrual cycle changes after vaccination.
