A Novel Approach for Evaluating Antibodies Against SARS-CoV-2 Using Menstrual Blood Collected from Sanitary Napkins Before and after Vaccination and Evaluation of the Visual Napkin Score

Abstract

Peripheral blood is mainly used for SARS-CoV-2 antibody testing. We evaluated menstrual blood, which can be collected noninvasively from sanitary napkins, as a specimen type for antibody testing. We also evaluated the visual napkin score and examined the relationship between the amount of menstrual blood collected. We tested napkins from 40 participants; 77.5% of samples could be tested with the antibody testing kits. In 35 unvaccinated participants, there were no IgG or IgM positive results. In ve vaccinated participants, IgG was positive in 100% of samples and IgM was positive in 60%. Four antibody test kits were used in this study. The results also differed depending on the antigen targeted by each antibody. The evaluation of antibodies using menstrual blood from napkins might have public health applications in the future as napkins could be developed into wearable monitoring sensors.