Evidence map›Paper›PMID 36410749›Full record

Observational studyCMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne2022

Observed versus expected rates of myocarditis after SARS-CoV-2 vaccination: a population-based cohort study.

Zaeema Naveed, Julia Li, Michelle Spencer, James Wilton, Monika Naus, Héctor Alexander Velásquez García, Michael Otterstatter, Naveed Zafar Janjua

Open access · goldAbstract readObservational Study
PubMed Full text at PMC Publisher
In one paragraph

Observational study in CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne, 2022. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 23 papers, 3 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
23citing papers in PubMed, 3 pooled it
7.4field-weighted citation impact, top 2% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

23 citing papers in PubMed, 3 syntheses or guidelines pooled it, 45 citations in OpenAlex.

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  17. CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne · 2023
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  19. Persistent myopericarditis after heterologous SARS-CoV-2 mRNA vaccination.CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne · 2023
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

8 authors at 2 institutions in 1 country.

Zaeema NaveedSchool of Population and Public Health (Naveed), University of British Columbia; British Columbia Centre for Disease Control (Li, Spencer, Wilton, Naus, Velásquez García, Otterstatter, Janjua), Vancouver, BC Naveed.Janjua@bccdc.ca.
Julia LiSchool of Population and Public Health (Naveed), University of British Columbia; British Columbia Centre for Disease Control (Li, Spencer, Wilton, Naus, Velásquez García, Otterstatter, Janjua), Vancouver, BC.
Michelle SpencerSchool of Population and Public Health (Naveed), University of British Columbia; British Columbia Centre for Disease Control (Li, Spencer, Wilton, Naus, Velásquez García, Otterstatter, Janjua), Vancouver, BC.
James WiltonSchool of Population and Public Health (Naveed), University of British Columbia; British Columbia Centre for Disease Control (Li, Spencer, Wilton, Naus, Velásquez García, Otterstatter, Janjua), Vancouver, BC.
Monika NausSchool of Population and Public Health (Naveed), University of British Columbia; British Columbia Centre for Disease Control (Li, Spencer, Wilton, Naus, Velásquez García, Otterstatter, Janjua), Vancouver, BC.
Héctor Alexander Velásquez GarcíaSchool of Population and Public Health (Naveed), University of British Columbia; British Columbia Centre for Disease Control (Li, Spencer, Wilton, Naus, Velásquez García, Otterstatter, Janjua), Vancouver, BC.
Michael OtterstatterSchool of Population and Public Health (Naveed), University of British Columbia; British Columbia Centre for Disease Control (Li, Spencer, Wilton, Naus, Velásquez García, Otterstatter, Janjua), Vancouver, BC.
Naveed Zafar JanjuaSchool of Population and Public Health (Naveed), University of British Columbia; British Columbia Centre for Disease Control (Li, Spencer, Wilton, Naus, Velásquez García, Otterstatter, Janjua), Vancouver, BC.
BC Centre for Disease Control · CAUniversity of British Columbia · CA

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundPostmarketing evaluations have linked myocarditis to SARS-CoV-2 mRNA vaccines. We sought to estimate the incidence of myocarditis after mRNA vaccination against SARS-CoV-2, and to compare the incidence with expected rates based on historical background rates in British Columbia.

methodsWe conducted an observational study using population health administrative data from the BC COVID-19 Cohort from Dec. 15, 2020, to Mar. 10, 2022. The primary exposure was any dose of an mRNA vaccine against SARS-CoV-2. The primary outcome was incidence of hospital admission or emergency department visit for myocarditis or myopericarditis within 7 and 21 days postvaccination, calculated as myocarditis rates per 100 000 mRNA vaccine doses, expected rates of myocarditis cases and observedto-expected ratios. We stratified analyses by age, sex, vaccine type and dose number.

resultsWe observed 99 incident cases of myocarditis within 7 days (0.97 cases per 100 000 vaccine doses; observed v. expected ratio 14.81, 95% confidence interval [CI] 10.83-16.55) and 141 cases within 21 days (1.37 cases per 100 000 vaccine doses; observed v. expected ratio 7.03, 95% CI 5.92-8.29) postvaccination. Cases of myocarditis per 100 000 vaccine doses were higher for people aged 12-17 years (2.64, 95% CI 1.54-4.22) and 18-29 years (2.63, 95% CI 1.94-3.50) than for older age groups, for males compared with females (1.64, 95% CI 1.30-2.04 v. 0.35, 95% CI 0.21-0.55), for those receiving a second dose compared with a third dose (1.90, 95% CI 1.50-2.39 v. 0.76, 95% CI 0.45-1.30) and for those who received the mRNA-1273 (Moderna) vaccine compared with the BNT162b2 (Pfizer-BioNTech) vaccine (1.44, 95% CI 1.06-1.91 v. 0.74, 95% CI 0.56-0.98). The highest observed-to-expected ratio was seen after the second dose among males aged 18-29 years who received the mRNA-1273 vaccine (148.32, 95% CI 95.03-220.69).

interpretationAlthough absolute rates of myocarditis were low, vaccine type, age and sex are important factors to consider when strategizing vaccine administration to reduce the risk of postvaccination myocarditis. Our findings support the preferential use of the BNT162b2 vaccine over the mRNA-1273 vaccine for people aged 18-29 years.

Indexed as

COVID-19Myocarditis2019-nCoV Vaccine mRNA-1273AgedBNT162 VaccineCohort StudiesCOVID-19 VaccinesFemaleHumansMalemRNA VaccinesSARS-CoV-2Vaccination2019-nCoV Vaccine mRNA-1273BNT162 VaccineCOVID-19 VaccinesmRNA Vaccines

Identifiers

PMID36410749
PMCPMC9828950
OpenAlexW4309667501

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC-ND
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Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.