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
  • Reporting Rate Calculator
  • Signal Detection
  • All 23 Articles →

Resources

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

Sister Sites

  • OpenMedicaid
  • OpenFeds
  • OpenImmigration
  • OpenSubsidies
  • OpenSpending
  • OpenMedicare
  • OpenLobby
  • WarCosts
  • OpenPrescriber
  • 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. FLU(H1N1)
  4. Prothrombin time
FLU(H1N1)×Prothrombin time

Prothrombin time Reports for FLU(H1N1)

#526 most reported symptom for this vaccine

7
Reports
1
Deaths
1
Hospitalizations
14.29
Mortality Rate
%
14.3
Hosp. Rate
%

Prothrombin time and FLU(H1N1)

Prothrombin time has been reported 7 times in association with FLU(H1N1) vaccination in VAERS.

Among these reports, 1 mentioned death (14.29%) and 1 involved hospitalization (14.3%).

Prothrombin time is the #526 most frequently reported symptom for FLU(H1N1) out of 993 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 7 reports of Prothrombin time after FLU(H1N1) vaccination may seem alarming, but context is critical.

The 14.29% 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 Prothrombin time occurred after vaccination, not that the vaccine caused it.
•Background rates: Prothrombin time 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

Red blood cells CSF positive7 reportsAtrial fibrillation7 reportsOrthostatic hypotension7 reportsPharyngeal erythema7 reports

Quick Facts

Reports:7
Deaths:1
Hospitalizations:1
% of Vaccine:—%
Rank:#526 of 993

Related Pages

FLU(H1N1) OverviewProthrombin time (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.