Anti-NMDA receptor encephalitis and vaccination: A disproportionality analysis

Area of Science:

• Neurology
• Immunology
• Pharmacovigilance

Background:

• Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a severe autoimmune neurological disorder.
• The exact causes of anti-NMDAR encephalitis are not fully understood.
• Investigating potential triggers like vaccination is crucial for understanding disease etiology.

Purpose of the Study:

• To explore potential pharmacovigilance signals connecting vaccination with the onset of anti-NMDAR encephalitis.
• To identify specific vaccines associated with increased reporting of anti-NMDAR encephalitis.

Main Methods:

• A case/non-case study design was employed using data from the World Health Organization's VigiBase database up to December 31, 2021.
• Individual Case Study Reports (ICSRs) coded as 'anti-NMDA receptor encephalitis' and linked to vaccination were analyzed.
• Reporting Odds Ratios (RORs) and 95% Confidence Intervals (CIs) were calculated for vaccine-associated encephalitis signals.

Main Results:

• Of 70 cases of anti-NMDAR encephalitis, 29 were linked to vaccination, with 53.8% occurring in children under 15.
• The median time from vaccination to encephalitis onset was 4 days.
• Significant reporting odds ratios were observed for diphtheria/polio/tetanus/pertussis, yellow fever, and human papillomavirus vaccines.

Conclusions:

• Pharmacovigilance signals suggest a potential association between certain vaccinations and anti-NMDAR encephalitis.
• Healthcare providers should maintain awareness of this potential risk and encourage reporting of post-vaccination encephalitis cases.
• Further investigation is warranted to elucidate the relationship between vaccination and anti-NMDAR encephalitis.