Abstract

Introduction: Some women are experiencing menstrual changes, including altered menstrual duration, volume (heavier bleeding), increased dysmenorrhea, and worsened Premenstrual Syndrome (PMS) following Coronavirus disease 2019 (COVID-19) spike vaccinations. Appreciation of these as temporal adverse events associated with COVID-19 spike vaccinations was slow to develop. The etiology of these menstrual adverse events associated with COVID-19 spike vaccination remains unknown.

Methods: The United States Department of Health and Human Services Vaccine Adverse Event Reporting System (VAERS) database was data mined for data reported adverse events affecting menstrual cycles by vaccine type.

Hypothesis: This article proposes the hypothesis that vaccinations can induce a temporary surge in histamine levels immediately post vaccination as part of the innate immune response. Increasing histamine levels is known to increase estrogen levels. Further, it is proposed that this temporary surge in histamine levels causes temporary Histamine Intolerance in some women and causes the menstrual adverse events temporally associated with vaccinations.

Conclusion: Prophylactic and therapeutic treatment of vaccines with diamine oxidase and/or specific antihistamines may reduce the incidence rate and/or severity of menstrual adverse events associated with vaccines with high reactogenicity, including SARS-CoV-2 vaccines and boosters. This model predicts menstrual associated adverse events incidence levels correspond to vaccine reactogenicity.

Keywords: Histamine; Menstruation; Menstrual cycle; Women’s health; mRNA vaccines; COVID-19 vaccine