Abstract Details

The unprecedented pace of COVID-19 vaccine development, use of novel mRNA technology and large-scale vaccination programs have engendered concerns of adverse events following immunization.

To describe the spectrum of acute neurological disorders among hospitalized patients who recently received COVID-19 mRNA vaccination.

We performed a multi-centre prospective observational study in 7 public acute hospitals. Hospitalized patients who were referred for neurological complaints and had COVID-19 mRNA vaccines, BNT162b2 and mRNA-1273, in the last 6 weeks were classified into central nervous system(CNS) syndromes, cerebrovascular disorders, peripheral nervous system(PNS) disorders, autonomic nervous system(ANS) disorders and immunization stress-related responses(ISRR). To contextualize our findings, data from National Immunization Registry was probed for the total number and demographic of individuals vaccinated in the corresponding period.

From 30 December 2020 to 20 April 2021, 1,398,074 persons (median age 59 years, 54.5% males) received COVID-19 mRNA vaccine (86.7% BNT162b2, 13.3% mRNA-1273); 915,344 (65.5%) completed 2 doses. Four hundred and fifty-seven (0.03%) patients were referred for neurological complaints [median age 67 years, 61.5% males; 95.8% received BNT162b2 and 4.2% mRNA-1273]; classified into 73 (16.0%) CNS syndromes, 286 (62.6%) cerebrovascular disorders, 59 (12.9%) PNS disorders, 0 ANS disorders and 39 (8.5%) ISRRs. Twenty-seven had cranial mononeuropathy, 11 of whom had Bell’s palsy. Of 33 patients with seizures, only 4 were unprovoked and occurred within 2 weeks of vaccination. All strokes occurred among individuals with pre-existing cardiovascular risk factors. We recorded 2 cases of cerebral venous thrombosis; none associated with thrombocytopenia. Five had mild flares of immune-mediated diseases.

Our observational study does not establish causality of the described disorders to vaccines and is limited by lack of baseline incidence data of several conditions. Nevertheless, we did not observe any obvious signal of serious neurological morbidity associated with mRNA vaccination. The benefits of COVID-19 vaccination outweigh concerns over neurological adverse events.