Menstrual 'PERIOD' changes after covid-19 vaccination, a link is plausible and must be investigated; changes to periods and unexpected vaginal bleeding are not listed, but primary care clinicians and

by Paul Alexander

those working in reproductive health are increasingly approached by people who have experienced these shortly after vaccination, over 30,000 reports of these events made to MHRA’s yellow card system


‘Robust research into this possible adverse reaction remains critical.’

‘Menstrual changes have been reported after both mRNA and adenovirus vectored covid-19 vaccines,1 suggesting that, if there is a connection, it is likely to be a result of the immune response to vaccination rather than a specific vaccine component. Vaccination against human papillomavirus (HPV) has also been associated with menstrual changes.9 Indeed, the menstrual cycle can be affected by immune activation in response to various stimuli, including viral infection: in one study of menstruating women, around a quarter of those infected with SARS-CoV-2 experienced menstrual disruption.10