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Transparent access to VAERS data for informed decision-making. We present the data as-is, with appropriate context and disclaimers.

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Data source: VAERS (Vaccine Adverse Event Reporting System)

Data through 2026 · Updated quarterly

Built by TheDataProject.ai · © 2026 VaccineWatch

Important: VAERS accepts reports of adverse events following vaccination. For any given report, there is no certainty that the reported event was caused by the vaccine. Reports may contain information that is incomplete, inaccurate, coincidental, or unverifiable. Most reports to VAERS are voluntary, which means they are subject to biases. This data cannot be used to determine if vaccines cause or contribute to adverse events.

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Important: VAERS reports alone cannot determine if a vaccine caused an adverse event. Reports may contain incomplete, inaccurate, or unverified information. Correlation does not equal causation.

  1. Home
  2. Vaccines
  3. Influenza, Seasonal (Flulaval Quadrivalent)
  4. Myocarditis
Influenza, Seasonal (Flulaval Quadrivalent)×Myocarditis

Myocarditis Reports for Influenza, Seasonal (Flulaval Quadrivalent)

#592 most reported symptom for this vaccine

31
Reports
3
Deaths
23
Hospitalizations
9.68
Mortality Rate
%
74.2
Hosp. Rate
%

Myocarditis and Influenza, Seasonal (Flulaval Quadrivalent)

Myocarditis has been reported 31 times in association with Influenza, Seasonal (Flulaval Quadrivalent) vaccination in VAERS. This represents 0.1% of all 52,111 reports for this vaccine.

Among these reports, 3 mentioned death (9.68%) and 23 involved hospitalization (74.2%).

Myocarditis is the #592 most frequently reported symptom for Influenza, Seasonal (Flulaval Quadrivalent) out of 2354 total symptoms.

Disclaimer: VAERS reports describe events that occurred after vaccination but do not establish that the vaccine caused the event. Many reported symptoms may be coincidental or related to underlying conditions.

What This Means

Seeing 31 reports of Myocarditis after Influenza, Seasonal (Flulaval Quadrivalent) vaccination may seem alarming, but context is critical.

The 9.68% mortality rate among these reports is elevated, but this reflects the severity of the condition itself rather than vaccine causation.

Important Context

•Association, not causation: These reports show Myocarditis occurred after vaccination, not that the vaccine caused it.
•Background rates: Myocarditis may occur naturally at baseline rates in the population, unrelated to vaccination.
•Anyone can report: VAERS accepts reports from anyone — patients, parents, healthcare providers — without requiring medical verification.
•Denominator missing: VAERS counts reports, not rates per dose. Without knowing how many doses were given, raw counts can be misleading. Learn more →

Similarly Ranked Symptoms

Aspartate aminotransferase normal31 reportsAggression31 reportsThrombosis31 reportsBorrelia test30 reports

Quick Facts

Reports:31
Deaths:3
Hospitalizations:23
% of Vaccine:0.1%
Rank:#592 of 2354

Related Pages

Influenza, Seasonal (Flulaval Quadrivalent) OverviewMyocarditis (All Vaccines)Why Raw Numbers MisleadTop Symptoms Analysis

Data Source

This data comes from the Vaccine Adverse Event Reporting System (VAERS), jointly managed by CDC and FDA.