`vaers_events_by_symptom`

Pack: vaers · Endpoint: https://gateway.pipeworx.io/vaers/mcp

VAERS report counts by symptom (MedDRA preferred term), optionally filtered to one vaccine and/or year range. Pass symptom as a substring (e.g. “headache”, “anaphyla”, “myocarditis”) to count how often it was reported; omit it to see the most-reported symptoms overall (optionally within one vaccine). Answers “how many VAERS reports mention myocarditis after the COVID-19 vaccine”, “most commonly reported symptoms for the flu vaccine in 2022”. Counts are MENTIONS — a report naming several symptoms and/or several vaccines contributes to each combination, so this is not a count of unique reports.

Parameters

Name	Type	Required	Description
`symptom`	string	no	Symptom substring (MedDRA preferred term), e.g. “headache”, “anaphyla”, “myocarditis”. Omit to see the top symptoms.
`vaccine`	string	no	VAERS vax_type code to narrow to one vaccine, e.g. “COVID19”. Optional.
`year_from`	number,string	no	Earliest report-received year to include (data covers 1990-2026).
`year_to`	number,string	no	Latest report-received year to include.
`limit`	number,string	no	Max rows (1-200, default 20).

Example call

Arguments

{
  "symptom": "headache",
  "vaccine": "COVID19"
}

curl

curl -X POST https://gateway.pipeworx.io/vaers/mcp \
  -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"vaers_events_by_symptom","arguments":{"symptom":"headache","vaccine":"COVID19"}}}'

TypeScript (@pipeworx/sdk)

import { Pipeworx } from '@pipeworx/sdk';
const pipeworx = new Pipeworx();

const result = await pipeworx.call('vaers_events_by_symptom', {
  "symptom": "headache",
  "vaccine": "COVID19"
});

More examples

{
  "limit": 10
}

Connect

Add this to your MCP client config, or use one-click install buttons:

{
  "mcpServers": {
    "vaers": {
      "url": "https://gateway.pipeworx.io/vaers/mcp"
    }
  }
}

See Getting Started for client-specific install steps.

vaers_events_by_symptom