Skip to main content
VaccineWatch
VaccinesSymptomsStatesAnalysisToolsDashboardCompare

VaccineWatch

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

Explore Data

  • Vaccines
  • Symptoms
  • Manufacturers
  • States
  • Dashboard
  • Compare Tool
  • Search

Deep Dives

  • The Denominator Problem
  • Onset Timing
  • Lot Number Analysis
  • COVID Impact
  • Myocarditis
  • Death Reports
  • Interactive Tools
  • All 23 Articles →

Resources

  • About
  • Methodology
  • FAQ
  • Glossary
  • Side Effects Guide
  • Vaccine Schedule
  • Vaccine Safety
  • Safety Timeline
  • Adverse Events
  • Is VAERS Reliable?
  • Report an Event
  • Disclaimer
  • VAERS Official Site ↗

Sister Sites

  • OpenMedicaid
  • OpenFeds
  • OpenSpending
  • OpenMedicare
  • OpenLobby
  • TheDataProject.ai

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.

⚠️

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 (Flublok Quadrivalent)
  4. Anaphylactic reaction
Influenza, Seasonal (Flublok Quadrivalent)×Anaphylactic reaction

Anaphylactic reaction Reports for Influenza, Seasonal (Flublok Quadrivalent)

#138 most reported symptom for this vaccine

11
Reports
0
Deaths
3
Hospitalizations
0
Mortality Rate
%
27.3
Hosp. Rate
%

Anaphylactic reaction and Influenza, Seasonal (Flublok Quadrivalent)

Anaphylactic reaction has been reported 11 times in association with Influenza, Seasonal (Flublok Quadrivalent) vaccination in VAERS. This represents 0.3% of all 3,407 reports for this vaccine.

Among these reports, 0 mentioned death (0.00%) and 3 involved hospitalization (27.3%).

Anaphylactic reaction is the #138 most frequently reported symptom for Influenza, Seasonal (Flublok Quadrivalent) out of 377 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 11 reports of Anaphylactic reaction after Influenza, Seasonal (Flublok Quadrivalent) vaccination may seem alarming, but context is critical.

The mortality rate among these reports is very low at 0.00%, suggesting most cases are non-fatal.

Important Context

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

Vision blurred12 reportsConfusional state12 reportsHypertension11 reportsMuscle spasms11 reports

Quick Facts

Reports:11
Deaths:0
Hospitalizations:3
% of Vaccine:0.3%
Rank:#138 of 377

Related Pages

Influenza, Seasonal (Flublok Quadrivalent) OverviewAnaphylactic reaction (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.