The National Institutes of Health (NIH) announced this week that it was awarding grants to five research institutions to look into reports from some women of irregular or missed menstrual periods after getting vaccinated against COVID-19.
The NIH in a press release said that the awards totaling $1.67 million would help determine whether there is a connection between any reported menstrual cycle changes and the Pfizer, Moderna and Johnson & Johnson vaccines currently in use in the U.S.
The federal agency said that some women have reported irregular or missing periods, heavier than normal bleeding and other menstrual changes.
In addition to immune responses to the vaccine, several other factors could play a role in altering a person’s menstruation, including pandemic-related stress, lifestyle changes adopted during the pandemic and becoming infected with COVID-19, according to the NIH.
While medical experts have said that abnormal periods could follow a COVID-19 vaccine, they have stressed that the irregularities did not present a safety issue, and are not a sign of infertility.
Those awarded the grants include researchers at Boston University, Harvard Medical School, Johns Hopkins University, Michigan State University and Oregon Health and Science University.
The funds are being provided through NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) and the NIH Office of Research on Women's Health.
NICHD Director Diana Bianchi said in a statement, “These rigorous scientific studies will improve our understanding of the potential effects of COVID-19 vaccines on menstruation, giving people who menstruate more information about what to expect after vaccination and potentially reducing vaccine hesitancy.”
The NIH said the studies will include data from geographically, racially and ethnically diverse populations, with one research project specifically focused on the vaccine’s impact on menstruation among adolescents.
The Pfizer-BioNTech vaccine is currently allowed for people as young as 12 under an emergency use authorization from the Food and Drug Administration, and has been fully approved for individuals ages 16 and older.
While previous reports noted that the Centers for Disease Control and Prevention (CDC) was looking into abnormal menstruation following vaccination, Martha Sharan, a public affairs officer for the CDC’s Vaccine Task Force, told the Chicago Tribune this week that it was not conducting additional research on the 1,589 incidents of “menstrual irregularity” it has tracked.
“At this time, CDC is not seeing any safety concerns that warrant additional surveillance of irregular menstrual symptoms reported to the Vaccine Adverse Event Reporting System,” Sharan said.
The CDC has said that while research on vaccination during pregnancy is ongoing, it continues to recommend that individuals who are pregnant or breastfeeding get the COVID-19 vaccine.
The agency has also not found any evidence to suggest that the vaccines cause fertility problems among women or men.