key: cord-0977472-hkx217gn
authors: Shimabukuro, Tom
title: Allergic reactions including anaphylaxis after receipt of the first dose of Moderna COVID‐19 vaccine — United States, December 21, 2020–January 10, 2021
date: 2021-02-28
journal: Am J Transplant
DOI: 10.1111/ajt.16517
sha: a153332c887e404a1b0587499a486c8dbe3a18a0
doc_id: 977472
cord_uid: hkx217gn

nan

vaccine. 1 Using methods previously described, 5 CDC and FDA identified reports of suspected anaphylaxis in VAERS, the national passive surveillance (i.e., spontaneous reporting) system for monitoring adverse events after immunization. 6 CDC physicians screened VAERS reports describing suspected severe allergic reactions and anaphylaxis and applied Brighton Collaboration case definition criteria for anaphylaxis * . 7 After initial screening, reports with sufficient evidence to suggest anaphylaxis were followed up by collecting information from medical records and through direct outreach to health care facilities and treating health care providers, and, in some cases, vaccine recipients. Physician reviewers classified all initially identified case reports as anaphylaxis or not anaphylaxis and used clinical judgment to further categorize reports that were considered not anaphylaxis as nonanaphylaxis allergic reactions or nonallergic adverse events. Nonallergic adverse events, mostly vasovagal (e.g., fainting or the sensation of fainting) or suspected anxiety-related, were excluded from the final analyses. Anaphylaxis and nonanaphylaxis allergic reaction cases with symptom onset occurring later than the day after vaccination (i.e., outside the 0-1-day risk window) were also excluded because of the difficulty in clearly attributing allergic reactions with onset later than this to vaccination. of first doses were administered in women. 5 The findings in this report are subject to at least two limitations.

First, analyses of passive surveillance data include reporting biases, both underreporting because of lack of awareness or compliance with reporting requirements and reporting guidance, as well as stimulated reporting related to increased awareness from media or other public information sources. Second, incomplete information in reports and potential data lags because of processing times might result in an undercount of cases, and lags in reporting for vaccine doses administered might underestimate denominator data.

However, reporting efficiency to VAERS for clinically severe adverse events is believed to be high. 9 It is reasonable to expect that diagnosis and reporting of an acute and clinically severe condition reporting adverse events after immunization to VAERS at https:// vaers.hhs.gov/repor tevent.html.

Project.

* Brighton level 1 represents the highest level of diagnostic certainty that a reported case is indeed a case of anaphylaxis; levels 2 and 3 represent successively lower levels of diagnostic certainty. Level 4 is a case reported as "anaphylaxis" but that does not meet the Brighton Collaboration case definition. Level 5 is a case that was neither reported as anaphylaxis nor meets the case definition. † Anaphylaxis and nonanaphylaxis allergic reaction cases with symptom onset occurring later than the day after vaccination (i.e., outside of the 0-1-day risk window) were excluded because of the difficulty in clearly attributing allergic reactions with onset outside this risk window to vaccination. § Four of the initial 47 nonanaphylaxis allergic reactions were excluded from the final analysis. Based on the Code of Federal Regulations, a serious adverse event is defined if one of the following is reported: death, life-threatening illness, hospitalization or prolongation of hospitalization, permanent disability, congenital anomaly, or birth defect. https://www. acces sdata.fda.gov/scrip ts/cdrh/cfdoc s/cfcfr/ cfrse arch.cfm?fr =312.32 ¶ https://www.aaaai.org/about -aaaai/ newsr oom/aller gy-stati stics

The Advisory Committee on Immunization Practices' interim recommendation for use of Moderna COVID-19 vaccine-United States

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*Four of the initial 47 nonanaphylaxis allergic reaction reports were excluded from the final analysis because symptom onset occurred later than the day after vaccination (i.e., outside the 0-1-day risk window). †Two nonanaphylaxis allergic reaction reports were missing information on time of symptom onset; percentage calculated among 41 case reports with onset documented. §Five anaphylaxis reports included a patient history of a previous anaphylaxis episode.