{
    "abstract": "Anecdotal reports of menstrual irregularities after receiving COVID-19 vaccines have been observed in post-authorisation and post-licensure monitoring. We aimed to identify and classify reports of menstrual irregularities and vaginal bleeding after COVID-19 vaccination submitted to a voluntary active surveillance system.\nThis observational cohort study included recipients of a COVID-19 vaccine who were aged 18 years and older and reported their health experiences to v-safe, a voluntary smartphone-based active surveillance system for monitoring COVID-19 vaccine safety in the USA, from Dec 14, 2020, to Jan 9, 2022. Responses to survey questions on reactions after vaccination were extracted, and a pre-trained natural language inference model was used to identify and classify free-text comments related to menstruation and vaginal bleeding in response to an open-ended prompt about any symptoms at intervals after vaccination. Related responses were further categorised into themes of timing, severity, perimenopausal and postmenopausal bleeding, resumption of menses, and other responses. We examined associations between symptom theme and respondent characteristics, including vaccine type and dose number received, solicited local and systemic reactions reported, and health care sought.\n63\u2009815 respondents reported on menstrual irregularities or vaginal bleeding, which included 62\u2009679 female respondents (1\u00b70% of 5\u2009975\u2009363 female respondents aged \u226518 years). Common themes identified included timing of menstruation (70\u2009981 [83\u00b76%] responses) and severity of menstrual symptoms (56\u2009890 [67\u00b70%] responses). Other themes included menopausal bleeding (3439 [4\u00b70%] responses) and resumption of menses (2378 [2\u00b78%] responses). Respondents submitting reports related to menopausal bleeding were more likely to seek health care than were those submitting reports related to other menstruation and vaginal bleeding themes.\nReports 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. Methods that leverage pretrained models to interpret and classify unsolicited signs and symptoms in free-text reports offer promise in the initial evaluation of unexpected adverse events potentially associated with use of newly authorised or licensed vaccines.\nCenters for Disease Control and Prevention.",
    "authors": [
        {
            "affiliation": "CDC COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, GA, USA. Electronic address: kwong@cdc.gov.",
            "firstname": "Karen K",
            "initials": "KK",
            "lastname": "Wong"
        },
        {
            "affiliation": "CDC COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, GA, USA.",
            "firstname": "Charles M",
            "initials": "CM",
            "lastname": "Heilig"
        },
        {
            "affiliation": "CDC COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, GA, USA.",
            "firstname": "Anne",
            "initials": "A",
            "lastname": "Hause"
        },
        {
            "affiliation": "CDC COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, GA, USA.",
            "firstname": "Tanya R",
            "initials": "TR",
            "lastname": "Myers"
        },
        {
            "affiliation": "CDC COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, GA, USA.",
            "firstname": "Christine K",
            "initials": "CK",
            "lastname": "Olson"
        },
        {
            "affiliation": "CDC COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, GA, USA.",
            "firstname": "Julianne",
            "initials": "J",
            "lastname": "Gee"
        },
        {
            "affiliation": "CDC COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, GA, USA.",
            "firstname": "Paige",
            "initials": "P",
            "lastname": "Marquez"
        },
        {
            "affiliation": "CDC COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, GA, USA.",
            "firstname": "Penelope",
            "initials": "P",
            "lastname": "Strid"
        },
        {
            "affiliation": "CDC COVID-19 Response Team, Centers for Disease Control and Prevention, Atlanta, GA, USA.",
            "firstname": "David K",
            "initials": "DK",
            "lastname": "Shay"
        }
    ],
    "conclusions": null,
    "copyrights": "Copyright \u00a9 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license. Published by Elsevier Ltd.. All rights reserved.",
    "doi": "10.1016/S2589-7500(22)00125-X\n10.1101/2022.03.30.22273165\n10.2139/ssrn.3998180\n10.1126/sciadv.abm7201\n10.1093/aje/kwac011",
    "journal": "The Lancet. Digital health",
    "keywords": [],
    "methods": null,
    "publication_date": "2022-08-13",
    "pubmed_id": "35961858\n33818592\n33914723\n34237049\n36303656\n35857495\n34991109\n8735352\n32707266\n23826779\n31575925\n33288478\n34555320\n28472893\n34020676\n34493264\n14756741\n34137123\n34692740\n34727554\n35051292\n29683909\n22310205",
    "results": null,
    "title": "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.",
    "xml": "<Element 'PubmedArticle' at 0x788504bcb3d0>"
}