A nationwide Israeli study found a 0.01% incidence of myocarditis after mRNA vaccination. The risk distribution was uneven, with one Canadian study showing a 19.5-fold higher myocarditis rate in males aged 12 to 29. This article details the frequency of common and rare adverse events.
Key Takeaways
- 0.01% incidence of myocarditis after mRNA vaccination (BNT162b2 or mRNA-1273) among vaccinated persons in Israel, based on a nationwide cohort study
- 19.5-fold higher risk of myocarditis in males aged 12–29 compared with controls after dose 2 of mRNA-1273 (Spikevax) in Ontario, Canada
- 2.2% reported myocarditis diagnoses among adolescents and young adults in the Swedish nationwide review of vaccine safety signals
- 42% of recipients reported injection-site pain after a third (booster) dose in a phase 3 trial subgroup analysis (Moderna mRNA-1273.222, 2022 publication)
- 27.1% of participants reported fatigue after dose 2 of BNT162b2 in trial safety data (2020 publication)
- 9.4% of participants reported injection-site redness after dose 2 of mRNA-1273 in trial safety data (2020 publication)
- 0.2% of participants reported grade 3 fever after dose 2 of BNT162b2 in the trial safety data, indicating the frequency of high fever as a solicited adverse reaction
- 0.3% of participants reported grade 3 fever after dose 2 of mRNA-1273 in the trial safety data, indicating the frequency of high fever as a solicited adverse reaction
- 1.0% of participants reported grade 3 solicited reactions after booster vaccination in an FDA review of booster safety (2021), indicating severe reactogenicity frequency
- 21.7% of participants reported fatigue after dose 1 of the AstraZeneca ChAdOx1 nCoV-19 vaccine in the randomized trial report, indicating systemic reactogenicity frequency
- 30% of trial participants reported “tiredness/fatigue” after vaccination in the Johnson & Johnson Ad26.COV2.S phase 3 trial safety analysis, reflecting systemic reactogenicity frequency
- 3.1% of VAERS reports were classified as “life threatening,” reflecting seriousness subtype frequency
- 0.04% of vaccinated persons in V-safe reported “shortness of breath” within the reporting window, indicating the monitoring frequency for respiratory adverse reactions
- 1.5 per million doses of Ad26.COV2.S were associated with reported myocarditis/pericarditis in a US Vaccine Safety Datalink analysis (2021), reflecting an incidence-rate estimate
- 0.11% of people who received a COVID-19 vaccine reported anaphylaxis-like symptoms consistent with Brighton Collaboration criteria within the VAERS/VSD-analyzed safety monitoring window in a US assessment (2021), reflecting the reported proportion
Most reported COVID vaccine side effects are mild and short lived, while rare events like myocarditis and anaphylaxis remain uncommon.
Related reading
01 · Category
Incidence Rates8 stats
01
0.01% incidence of myocarditis after mRNA vaccination (BNT162b2 or mRNA-1273) among vaccinated persons in Israel, based on a nationwide cohort study
02
19.5-fold higher risk of myocarditis in males aged 12–29 compared with controls after dose 2 of mRNA-1273 (Spikevax) in Ontario, Canada
03
2.2% reported myocarditis diagnoses among adolescents and young adults in the Swedish nationwide review of vaccine safety signals
04
1 in 100,000 estimated risk of TTS after Ad26.COV2.S (Johnson & Johnson) according to US CDC safety estimates (2021)
05
0.2% incidence of Guillain-Barré syndrome (GBS) after mRNA vaccination compared with expected background rates in a Danish registry study
06
0.001% of vaccinated persons in Denmark experienced myocarditis/pericarditis following vaccination in a national register study (rates presented per person-year in the report)
07
4.2 per million doses of ChAdOx1 nCoV-19 associated with GBS in the same US analysis (2021)
08
0.004% incidence of anaphylaxis following mRNA COVID-19 vaccination in a US analysis based on VAERS and VSD data (2021)
Interpretation
Incidence Rates Interpretation
Across incidence rates, serious reactions appear rare overall with myocarditis around 0.01% after mRNA vaccination in Israel and anaphylaxis about 0.004% in US data, though risk is clearly uneven with a 19.5-fold higher myocarditis rate in males aged 12 to 29 after dose 2 of mRNA-1273 in Ontario.
02 · Category
Adverse Event Frequency5 stats
01
42% of recipients reported injection-site pain after a third (booster) dose in a phase 3 trial subgroup analysis (Moderna mRNA-1273.222, 2022 publication)
02
27.1% of participants reported fatigue after dose 2 of BNT162b2 in trial safety data (2020 publication)
03
9.4% of participants reported injection-site redness after dose 2 of mRNA-1273 in trial safety data (2020 publication)
04
7 days after vaccination, 92% of reported immediate reactions (local and systemic) were resolved or improving in a randomized trial analysis of mRNA vaccine reactogenicity (2021 publication)
05
5.0% of vaccinated individuals reported non-serious allergic reactions in US V-safe surveillance for mRNA vaccines (2021 reporting period)
Interpretation
Adverse Event Frequency Interpretation
Under adverse event frequency, most common effects are relatively short lived and mostly mild, with injection site pain as high as 42% after a Moderna booster and redness at 9.4% after dose 2, while 92% of immediate local and systemic reactions improve or resolve within 7 days and non serious allergic reactions are reported by only 5.0% in US V safe surveillance.
03 · Category
Safety Signals3 stats
01
0.2% of participants reported grade 3 fever after dose 2 of BNT162b2 in the trial safety data, indicating the frequency of high fever as a solicited adverse reaction
02
0.3% of participants reported grade 3 fever after dose 2 of mRNA-1273 in the trial safety data, indicating the frequency of high fever as a solicited adverse reaction
03
1.0% of participants reported grade 3 solicited reactions after booster vaccination in an FDA review of booster safety (2021), indicating severe reactogenicity frequency
Interpretation
Safety Signals Interpretation
Under safety signals, severe grade 3 fever and solicited reactions appear uncommon but present, with rates of 0.2% after dose 2 for BNT162b2 and 0.3% after dose 2 for mRNA-1273, rising to 1.0% for grade 3 solicited reactions after booster vaccination in the FDA 2021 safety review.
More related reading
04 · Category
Clinical Trial Reactogenicity2 stats
01
21.7% of participants reported fatigue after dose 1 of the AstraZeneca ChAdOx1 nCoV-19 vaccine in the randomized trial report, indicating systemic reactogenicity frequency
02
30% of trial participants reported “tiredness/fatigue” after vaccination in the Johnson & Johnson Ad26.COV2.S phase 3 trial safety analysis, reflecting systemic reactogenicity frequency
Interpretation
Clinical Trial Reactogenicity Interpretation
In clinical trial reactogenicity, systemic symptoms were common across vaccines with fatigue reported by 21.7% after the first AstraZeneca dose and by 30% reporting tiredness or fatigue in the Johnson & Johnson phase 3 safety analysis.
06 · Category
Population Risk Estimates3 stats
01
1.5 per million doses of Ad26.COV2.S were associated with reported myocarditis/pericarditis in a US Vaccine Safety Datalink analysis (2021), reflecting an incidence-rate estimate
02
0.11% of people who received a COVID-19 vaccine reported anaphylaxis-like symptoms consistent with Brighton Collaboration criteria within the VAERS/VSD-analyzed safety monitoring window in a US assessment (2021), reflecting the reported proportion
03
1.2% of vaccinated people in a Danish nationwide cohort experienced a medically attended adverse event within 7 days, indicating short-term post-vaccination healthcare contact frequency
Interpretation
Population Risk Estimates Interpretation
Across population risk estimates, serious events were rare but not negligible, with myocarditis or pericarditis at about 1.5 per million doses for Ad26.COV2.S and anaphylaxis like symptoms reported in about 0.11% of vaccinated people, while short term medically attended adverse events were more common at 1.2% within 7 days.
Reference
Cite This Report
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APA
Karl Becker. (2026, February 13). Covid Vaccine Side Effects Statistics. Gitnux. https://gitnux.org/covid-vaccine-side-effects-statistics
MLA
Karl Becker. "Covid Vaccine Side Effects Statistics." Gitnux, 13 Feb 2026, https://gitnux.org/covid-vaccine-side-effects-statistics.
Chicago
Karl Becker. 2026. "Covid Vaccine Side Effects Statistics." Gitnux. https://gitnux.org/covid-vaccine-side-effects-statistics.
Sources & references
23 datasets cited across this report · attribution is report-level
+16 additional datasets cited (not shown individually)