• The claim is rooted in a preprint (not peer-reviewed) posted on Preprints.org in April 2025 by authors including Peter McCullough and James Thorp, who have a documented history of spreading vaccine misinformation¹.
• The preprint queried VAERS and reported a Proportional Reporting Ratio (PRR) of 24.5 for the term “homicidal ideation” when comparing COVID-19 vaccine adverse-event reports to influenza vaccine reports¹.
• A PRR measures the disproportionality of reports within a passive surveillance database; it does not measure actual risk, incidence, or likelihood of an adverse event occurring in vaccinated people. The CDC and FDA explicitly state that VAERS “cannot determine if a vaccine caused an adverse event” and is not designed to calculate risk²³.
• The preprint itself acknowledges that VAERS “cannot compare vaccine adverse events to a non-vaccinated control population, nor does it allow for prospective observational analysis,” meaning its data cannot support causal conclusions about risk¹.
• The comparison is methodologically flawed: it contrasts 48 months of COVID-19 vaccine reports (during a pandemic with unprecedented media coverage, public scrutiny, and reporting mandates) against 420 months of influenza vaccine reports, conflating reporting frequency with biological risk¹.
• Social media posts and outlets such as Global Research falsely recast this reporting ratio as “25 times more likely,” committing the well-documented fallacy of treating VAERS PRRs as proven causal risks³².
• No peer-reviewed epidemiological study or randomized controlled trial has found that COVID-19 vaccines increase the actual risk of homicidal ideation.

Overall validity: 5%

1. Association between COVID-19 Vaccination and ...
2. Fact Check: Viral posts misuse VAERS data to make false claims about COVID-19 vaccines - KCRA
3. Viral Posts Misuse VAERS Data to Make False Claims About COVID-19 Vaccines - FactCheck.org