• The “157×” figure originates from a retrospective VAERS study (Cosgrove et al., 2025) that reports an odds ratio of 157 for toxic encephalopathy when comparing COVID-19 vaccine adverse-event reports to influenza vaccine reports¹. The study’s methods state that these are odds ratios (ORs) derived from passive surveillance data, not measures of incidence or risk¹.
• The U.S. Vaccine Adverse Event Reporting System (VAERS) is a passive, voluntary database that the CDC and FDA explicitly say cannot be used to assess incidence rates, establish causality, or directly compare risk between different vaccines².
• The 157 value is a disproportionality metric (reporting odds ratio), not a risk ratio; it reflects the relative proportion of a specific event among all submitted reports, not the actual probability of developing toxic encephalopathy³⁴.
• Presenting this reporting odds ratio as a proven 157-fold increase in “risk” is a well-documented misinterpretation of VAERS data³⁴.
• Large population-based studies contradict the claimed risk elevation: a primary-care cohort study found a standardized incidence ratio of 0.79 for encephalitis after the BNT162b2 vaccine—below the expected background rate—and overall post-vaccination encephalitis incidence is estimated at roughly 1.9 cases per million doses³.
• No credible, peer-reviewed epidemiological study has demonstrated a 157-fold increase in the actual risk of toxic encephalopathy from COVID-19 vaccines.

Overall validity: 0%

1. COVID-19 mRNA vaccination: implications for the central nervous ...
2. Neurologic complications of vaccination
3. COVID‑19 vaccines increase the risk of autoimmune encephalitis by 79 times compared with flu shots
4. COVID‑19 vaccines increase the risk of delusions 50 times compared with flu shots.