McLean wins NIH grant to explore links between COVID-19 vaccine and menstrual cycle changes

In research that will add important data to the experience of vaccines on women's health, Laura Payne, PhD, director of McLean Hospital's Clinical and Translational Pain Research Laboratory, has received a grant from the National Institutes of Health (NIH) to explore potential links between SARS-CoV-2 vaccination and menstrual cycle changes.

The one-year grant is part of $1.67 million in supplemental grants offered to five institutions to investigate the topic. The supplemental grants are funded by NIH's Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) and the NIH Office of Research on Women's Health.

There is currently no known link between the vaccines and menstrual cycle changes. After COVID-19 vaccination, some women have reported menstrual changes that include variations in blood flow or cycle length. Such reports of menstrual cycle changes are low and currently anecdotal.

The menstrual cycle involves a complex interplay among hormones and reproductive organs. Many factors can potentially lead to temporary menstrual cycle changes, including stress, changes in contraceptive use, and infection with SARS-coV-2 (the virus that causes COVID-19). An immune response to a COVID-19 vaccine could also potentially affect the interaction between immune cells and the uterus to cause temporary changes in the menstrual cycle.

Clinical trials for Pfizer, Moderna, and Johnson & Johnson SARS-CoV-2 vaccines tracked participants' last menstrual period, but the trials did not examine menstrual cycles extensively. The rigorous scientific studies funded by the NIH can provide more information on whether vaccines affect menstrual cycles, the mechanisms behind any potential changes, and how long such changes, if any, may last. The data from the rigorous studies will provide information that could reduce vaccine hesitancy among people who menstruate.

According to Payne, the menstrual cycle is an indicator of health that has not been historically recognized as an important component in the experience of women.

In many areas of health research, we don't often study the menstrual cycle. We don't acknowledge the potential role that hormonal changes reproductive-age women go through could have on outcomes."

Laura Payne, PhD, Director, McLean Hospital's Clinical and Translational Pain Research Laboratory

Payne's research will focus on the role of inflammation COVID-19 vaccines may have on the menstrual cycles of adolescent girls. Payne has been conducting menstrual pain research for over a decade and has extensive experience tracking the menstrual cycle in great detail. Her research team will examine saliva samples to determine levels of SARS COVID antibodies, the antibodies' relationship with ovarian hormones, and the amount of inflammation participants experience in response to the vaccine.

Menstruation itself is an inflammatory process. Vaccines, including the COVID-19 vaccine, typically elicit an inflammatory response in recipients. Chemicals in the body-;inflammatory cytokines-;trigger inflammation when released upon receipt of the vaccine.

Animal models suggest these inflammatory markers may affect estrogen receptor expressions, having an impact on estrogen that can then affect the menstrual cycle. However, currently, there is insufficient data to support this hypothesis.

Payne's study will measure levels of estradiol and progesterone, the two primary ovarian hormones. Her research team will measure the hormones, inflammation, and antibodies at key points before and after participants receive vaccines over the course of the two-month dosing regimen. Vaccinated participants will be compared with a control group of unvaccinated participants. The researchers will also measure self-reported stress and its potential role in inflammation.

The study will focus on adolescents aged 14 to 18. Payne's lab will recruit a cohort of participants from a larger group study on menstrual pain the team recently began on this population.

The research team will collaborate closely with Steve Granger, PhD, CSO, at Salimetrics. Granger is a cytokine biologist who specializes in analyzing SARS-coV-2 in saliva samples. The use of saliva samples from participants in place of blood draws will greatly expedite the pace of research.

Payne aims to collect all data within one year with publication to follow shortly thereafter.

"I think it's fantastic that NICHD is supporting this research and decided to make a special call to look at an important area that wasn't part of the vaccines' clinical trials," Payne said.

She added: "I think if these data are collected and are more systematically examined in future trials, it can give women more confidence to say, 'I know that they were looking at the things that matter to me.'"