Can the period change because of a corona vaccination with Biontech, Moderna or Johnson & Johnson? A recent study now provides the answer.
Portland – With the increasing number of corona vaccinations administered *, reports of possible side effects have also increased in social networks. Women reported bleeding, cramping, and other changes * in their menstruation. This also resulted in criticism of the research focuses on vaccine side effects. Critics complained that menstrual cramps as side effects * have been systematically ignored.
That should change now, because more and more studies are now dealing with the subject of corona vaccination and periods. A recently published study from the USA * comes to the first results.
Corona vaccination and period: Study provides information on possible side effects
The researchers have published the results of their study in the journal Obstetrics & Gynecology. The scientists evaluated anonymized data from an app used to monitor fertility in women aged 18 to 45 who are not using hormonal contraception. About 2400 women in the dataset were vaccinated with Biontech / Pfizer, * Moderna *, or Johnson & Johnson *. The data from 1500 unvaccinated women were used as a comparison group. The distribution of the corona vaccines within the study participants at a glance:
| vaccine | portion |
| Biontech / Pfizer | 55 percent |
| Moderna | 35 percent |
| Johnson & Johnson | 7 percent |
Corona vaccination and menstruation: periods can change
The researchers compared data from three consecutive cycles before vaccination with three cycles during and after vaccination. In the unvaccinated women there were six consecutive cycles.
The result : The corona vaccination can slightly delay the period in women. On average, the first vaccine dose was associated with an increase in cycle length of 0.64 days and the second dose with an increase of 0.79 days. In addition, this change is likely to be only temporary, according to the researchers.
This slight increase in the menstrual cycle is not clinically significant. Any change of less than eight days is classified as normal by the International Federation of Gynecology and Obstetrics. Cycles usually last around 28 days, but the exact duration varies from woman to woman and also over life. It can change even in times of stress.
According to the researchers, the change in connection with the vaccination could be due to an immune system reaction to the vaccine. A boosted immune system could therefore affect the so-called hypothalamus-pituitary-ovarian axis. According to the lead author of the study, Alison Edelman from Oregon Health & Science University, this is the “highway of communication between the brain and ovaries and uterus”. In particular, the production of inflammatory proteins called cytokines appears to interfere with the way this axis regulates the timing of menstrual cycles.
Corona: Effects of vaccination with Biotech and Moderna on the period
The changes seem to be most pronounced when vaccination occurs early in the follicular phase, which begins on the first day of menstruation and ends with the onset of ovulation. If two vaccinations with Biontech or Moderna fell on the same cycle, the bleeding was delayed by an average of two days.
Researcher Edelman said the results of the study were “very reassuring”. Especially since the study confirms the experiences of menstruating who noticed a change in their period after their vaccination. The research work could also help to refute any misinformation on the topic on the Internet.
The researchers now want to collect further data in order to confirm a long-term return of the cycles to the initial value. In addition, the differences between the individual corona vaccines * should also be analyzed. A global survey could provide information on this. (Sophia Lother / AFP) * fr.de is an offer from IPPEN.MEDIA.
