A.4 Neurological events following COVID-19 vaccination: does ethnicity matter?

Abstract

Background: Neurological complications following vaccinations have been described before, but the rates of neurological complications, and their variation by ethnicity, following COVID-19 vaccine are not well-known. Methods: We conducted a population-based cohort study of Ontarians aged 18 years and over who received their first COVID-19 vaccine, and followed them for six weeks to estimate the incidence of neurological events, ascertained using validated case definitions based on ICD-10 codes. Ethnicity was defined using last name surname algorithm. We used multivariable logistic regression models, adjusting for age, sex, and vaccine-type to evaluate ethnic differences. Results: In the included 10,063,466 Ontario residents, incidence of GBS (n=72), CVST (n=52) and transverse myelitis (n=25) after first COVID-19 vaccine was rare. The crude rate of ischemic stroke (240/1,000,000 people) was the highest followed by Bell’s palsy (54/1,000,000). Compared to the general population, the adjusted odds of ischemic stroke and Bell’s palsy were lower in Chinese (aOR_Bell’s 0.62; 0.39-0.98 and a OR_{ischemic stroke} 0.74; 0.59-0.91) and South Asians (aOR_Bell’s 0.83; 0.52-1.31 and aOR_{ischemic stroke} 0.84; 0.65-1.08). Conclusions: The incidence of neurological events following COVID-19 vaccine is low, and it varies by ethnicity. Our findings should encourage vaccination against COVID-19 in all ethnic groups.