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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. Polio (Oral)
  4. Encephalitis
Polio (Oral)×Encephalitis

Encephalitis Reports for Polio (Oral)

#105 most reported symptom for this vaccine

86
Reports
10
Deaths
63
Hospitalizations
11.63
Mortality Rate
%
73.3
Hosp. Rate
%

Encephalitis and Polio (Oral)

Encephalitis has been reported 86 times in association with Polio (Oral) vaccination in VAERS. This represents 0.3% of all 27,089 reports for this vaccine.

Among these reports, 10 mentioned death (11.63%) and 63 involved hospitalization (73.3%).

Encephalitis is the #105 most frequently reported symptom for Polio (Oral) out of 558 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 86 reports of Encephalitis after Polio (Oral) vaccination may seem alarming, but context is critical.

The 11.63% 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 Encephalitis occurred after vaccination, not that the vaccine caused it.
•Background rates: Encephalitis 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

Erythema multiforme89 reportsMyasthenic syndrome87 reportsInjury83 reportsEncephalopathy82 reports

Quick Facts

Reports:86
Deaths:10
Hospitalizations:63
% of Vaccine:0.3%
Rank:#105 of 558

Related Pages

Polio (Oral) OverviewEncephalitis (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.