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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 (Flublok Quadrivalent)
  4. Blood test
Influenza, Seasonal (Flublok Quadrivalent)×Blood test

Blood test Reports for Influenza, Seasonal (Flublok Quadrivalent)

#100 most reported symptom for this vaccine

16
Reports
1
Deaths
6
Hospitalizations
6.25
Mortality Rate
%
37.5
Hosp. Rate
%

Blood test and Influenza, Seasonal (Flublok Quadrivalent)

Blood test has been reported 16 times in association with Influenza, Seasonal (Flublok Quadrivalent) vaccination in VAERS. This represents 0.5% of all 3,407 reports for this vaccine.

Among these reports, 1 mentioned death (6.25%) and 6 involved hospitalization (37.5%).

Blood test is the #100 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 16 reports of Blood test after Influenza, Seasonal (Flublok Quadrivalent) vaccination may seem alarming, but context is critical.

The 6.25% 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 Blood test occurred after vaccination, not that the vaccine caused it.
•Background rates: Blood test 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

COVID-1917 reportsSARS-CoV-2 test positive17 reportsHerpes zoster16 reportsLip swelling16 reports

Quick Facts

Reports:16
Deaths:1
Hospitalizations:6
% of Vaccine:0.5%
Rank:#100 of 377

Related Pages

Influenza, Seasonal (Flublok Quadrivalent) OverviewBlood test (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.