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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. Head injury
Influenza, Seasonal (Flulaval Quadrivalent)×Head injury

Head injury Reports for Influenza, Seasonal (Flulaval Quadrivalent)

#117 most reported symptom for this vaccine

292
Reports
1
Deaths
19
Hospitalizations
0.34
Mortality Rate
%
6.5
Hosp. Rate
%

Head injury and Influenza, Seasonal (Flulaval Quadrivalent)

Head injury has been reported 292 times in association with Influenza, Seasonal (Flulaval Quadrivalent) vaccination in VAERS. This represents 0.6% of all 52,111 reports for this vaccine.

Among these reports, 1 mentioned death (0.34%) and 19 involved hospitalization (6.5%).

Head injury is the #117 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 292 reports of Head injury after Influenza, Seasonal (Flulaval Quadrivalent) vaccination may seem alarming, but context is critical.

The mortality rate among these reports is very low at 0.34%, suggesting most cases are non-fatal.

Important Context

•Association, not causation: These reports show Head injury occurred after vaccination, not that the vaccine caused it.
•Background rates: Head injury 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

Abdominal pain upper305 reportsInduration299 reportsComputerised tomogram291 reportsInjection site mass288 reports

Quick Facts

Reports:292
Deaths:1
Hospitalizations:19
% of Vaccine:0.6%
Rank:#117 of 2354

Related Pages

Influenza, Seasonal (Flulaval Quadrivalent) OverviewHead injury (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.