Research Letter

Is the phase of the menstrual cycle relevant when getting the covid-19 vaccine?

A.F. is the founder and product owner of LunarApp, the smartphone application used for data collection for the present study. The remaining authors report no conflict of interest.

B.V.R. received funding from Agència de Gestió d'Ajuts Universitaris i de Recerca (award number: 2020-18). This funding source had no direct role in this manuscript. J.L.F., J.C. and J.L.A. received funding from EU H2020 Crowd4SDG project (Award Number: 872944). This funding source had no direct role in this manuscript.