After Katherine Lee received her COVID-19 vaccine, she and a colleague talked about their side effects.
While expecting injection site pain and mild fever, they both noticed a symptom they did not expect: their menstrual cycles changed. When Lee started talking to other people who were menstruating, she heard that they also experienced periods that came earlier, felt heavier or just seemed abnormal.
“The menstrual cycle is a very flexible and dynamic process and responds to many different things in life, such as stress, physical or mental or immune changes,” said Lee, the postdoctoral scientist in the Department of Public Health at the University of Washington. School of Medicine in St. Louis, said. “The menstrual cycle is supposed to respond and adapt.”
Lee reached out to her high school professor, Kathryn Clancy, head of the Clancy Lab at the University of Illinois, which focuses on research on women’s health. She mentions the irregular cycles and Clancy is interested. Then she received her first dose.
” A while after a week after this first dose of Moderna and I’ve never had such a period – not even in my twenties when I had a very heavy cycle, ” Clancy said.
Clancy has her experience on Twitter and people kept the conversation going with their own stories.
“A lot of people have noticed something, but still haven’t heard of (menstrual changes) as a side effect,” Lee said. “So many things can affect people’s menstrual experiences. So, we just thought if it’s a side effect of … this kind of vaccination, it would be good for people to be prepared. “
Both researchers said they are pro-vaccine and that they are conducting the research to understand the full range of potential side effects.
“We need to do more work to notice when there are different effects for different people so that we can work better with the preparation of these side effects,” Clancy explained. “For example, if people know it will bloom more, they will have more booklets with them.”
Previous vaccine studies and menstruation
It is not known whether previous studies on other vaccines have looked at whether it affects menstruation, experts said.
Clancy said the National Institutes of Health in the 1990s recommended a balanced recruitment for drug trials, that women should be included in studies.
“We make a lot of assumptions about vaccines and side effects based on data that do not represent all bodies,” she said. “There are biological and cultural consequences for all sorts of different phenomena, and we have to do really carefully to study them.”
Although researchers do not understand how vaccines can affect menstruation, they do know how COVID-19 affects menstruation.
“There are some studies that show that how the COVID virus actually enters the human cells and that these receptors are found partially in the GIT, kidneys, possibly the uterus, possibly the placenta,” said Dr. Island Jewish Medical Center, TODAY told.
Yukhayev wonders if the inflammation that plays a role in the virus is contributing to the changes.
“Maybe not the virus itself, but maybe it’s the antibodies and the inflammatory response it creates through the body,” he said.
Yukhayev urges people to talk to their doctors if they notice the changes in the period and are worried.
Some people may want to take a pregnancy test, while others experience a change in menstruation for other reasons, such as fibroids, endometriosis or polycystic ovary syndrome (PCOS), especially if it lasts longer.