Global estimates of vaccine-associated narcolepsy from 1967 to 2023

Regional evidence on the signal detection between narcolepsy and vaccines is scarcely available and insufficiently understood, thus impeding a comprehensive understanding of this relationship on a global scale. Therefore, this study aimed to evaluate the global estimates of vaccine-associated narcolepsy, discern its association with specific vaccines, and thereby contribute to the advancement of more efficient vaccination protocols. This study utilized data from the international pharmacovigilance database concerning vaccine-associated narcolepsy from 1967 to 2023. Global reporting counts, reported odds ratios (ROR), and information components (IC) were analyzed to identify the signal detection between the 16 vaccines and the occurrence of vaccine-associated narcolepsy across 140 countries. We identified 2,183 reports (male, n = 870 [39.85%]) of vaccine-associated narcolepsy from 5,291 reports of narcolepsy. Vaccine-associated narcolepsy has been reported since 2009. The highest disproportionality signals for narcolepsy were observed with influenza vaccines (ROR, 156.53 [95% CI, 147.62-165.97]; IC, 6.72 [IC_0.25, 6.63]), followed by papillomavirus and encephalitis vaccines. Concerning age and sex-specific signals, reports of vaccine-associated narcolepsy were associated with age groups between 12 and 17 years and males. Most of these adverse events had a long time to onset (mean: 115 days). Although our findings do not permit any inference of causality, influenza vaccines showed highest signal detection between vaccines and narcolepsy followed by papillomavirus and encephalitis vaccines. COVID-19 mRNA vaccines, despite large number of reports, showed no evidence of signal detection with narcolepsy.