Exhibit 941 ยท Peer-reviewed study
Menstrual irregularities and vaginal bleeding after COVID-19 vaccination reported to v-safe active surveillance, USA in December, 2020-January, 2022: an observational cohort study
Reports of heterogeneous symptoms related to menstruation or vaginal bleeding after COVID-19 vaccination are being submitted to v-safe, although this study is unable to characterise the relationship of these symptoms to COVID-19 vaccination.
CDC authors apply a pretrained natural language inference model to V-safe free-text comments from 14 December 2020 to 9 January 2022. Among 5,975,363 female respondents aged 18 and older, 62,679 (1.0%) reported menstrual irregularities or vaginal bleeding, and respondents reporting menopausal bleeding were more likely to seek health care. The paper states that V-safe data cannot show whether the symptoms occur above baseline rates or are caused by vaccination.
- Source
- Wong KK, Heilig CM, Hause A, Myers TR, Olson CK, Gee J, Marquez P, Strid P, Shay DK (CDC COVID-19 Response Team); The Lancet Digital Health 4(9):e667-e675
- Date
- August 2022 (online 9 August 2022)
- Quoted from
- Summary, Interpretation
- Grade
- Peer-reviewed
- Document
- https://doi.org/10.1016/S2589-7500(22)00125-X
- Accessed
- 2026-11-10
- Cited by
- Findings citing this exhibit
- Note
- Open access via PubMed Central (PMC9363036; PMID 35961858). The paper analyzes the V-safe free-text field; it is the only Lancet Digital Health 2022 paper with Wong as author found in a PubMed search on v-safe.