Apropos of menstrual changes and abnormal uterine bleeding after COVID-19 vaccination

It is news of 28 October 2022 that the Pharmacovigilance Risk Assessment Committee of the European Medicines Agency has recommended to add heavy menstrual bleeding among the side effects of unknown frequency inside the package insert of nucleoside-modified messenger ribonucleic acid vaccines to prevent coronavirus disease 2019 (COVID-19). The decision has been made in the light of the numerous reports of unexpected menstrual changes or abnormal uterine bleeding following COVID-19 vaccination. Here we advance a possible involvement of the particular adenohypophyseal microcirculation in these strange and still unexplained events.