Low incidence of neurological recurrent side-effects following COVID-19 reimmunization

Background: Individuals who suffered a neurological adverse event after the Coronavirus disease (COVID-19) vaccine could hesitate and defer reimmunization.

Aim: We examine the risk of recurrence following reimmunization among patients who developed a neurological event after the first dose of the COVID-19 mRNA vaccine.

Design: Observational study.

Methods: Individuals who developed an adjudicated neurological adverse event (based on Brighton Collaboration criteria) within 6 weeks of the first dose of the COVID-19 vaccine requiring hospitalization were enrolled into a multicenter national registry in Singapore. Neurological recurrence, defined by the development of another neurological event within 6 weeks of the second vaccine dose, was reviewed. Clinical characteristics were compared between patients who chose to proceed or withhold further vaccination, and between those who received timely (3-6 weeks) or delayed (>6 weeks) reimmunization.

Results: From 235 patients (median age, 67 years; 63% men) who developed an adjudicated neurological event after their first dose of mRNA vaccine between 30 December 2020 and 20 April 2021, 181 (77%) chose to undergo reimmunization. Those who decided against reimmunization were older (median age, 74 vs. 66 years) and had greater physical disability following their primary neurological event (46% vs. 20%, P < 0.001). Patients who suffered greater physical disability were three times more likely to delay their reimmunization (odds ratio 3.36, 95% confidence interval: 1.76-6.40). Neurological recurrence was observed in only four individuals (three with seizures and one with myasthenia gravis exacerbation).

Conclusions: A prior neurological event should not necessarily preclude reimmunization and the decision to proceed with reimmunization should consider the overwhelming benefits conferred by vaccination toward ending this pandemic.