NEURO-COVAX: An Italian Population-Based Study of Neurological Complications After COVID-19 Vaccines

Objective: In this Italian population-based study, we aimed to evaluate neurological complications after first and/or second dose of COVID-19 vaccines and factors potentially associated with adverse effects. Methods Our study included adults aged-18 years and older, receiving two vaccine doses in vaccination Hub Novegro (Lombardy) between July 7–16 2021. NEURO-COVAX questionnaire was able to capture neurological events, onset and duration. Data digitized centrally by Lombardy-Region were used to match demographic/clinical characteristics and identify a vulnerable profile. Associations between vaccine-lines and development of complications were assessed. Results NEURO-COVAX-cohort included 19.108 vaccinated-people: 15.368 mRNA BNT162b2, 2077 mRNA-1273, 1651 ChAdOx1nCov-19 and 12 Ad26.COV2, subsequently excluded. About 31.3% of sample developed post-vaccination neurological complications, particularly ChAdOx1nCov-19. Vulnerable clinical profile emerged, over 40% of symptomatic people showed comorbidities in clinical history. Defining neurological risk profile, we found increased risk for ChAdOx1nCov-19 of tremor (OR:5.12, 95% CI:3.51–7.48), insomnia (OR:1.87, 95% CI:1.02–3.39); muscle spasms (OR:1.62, 95% CI:1.08–2.46) and headache (OR:1.49, 95% CI:0.96–1.57); for mRNA-1273 of parethesias (OR:2.37, 95% CI:1.48–3.79), vertigo (OR:1.68, 95% CI:1.20–2.35), diplopia (OR:1.55, 95% CI:0.67–3.57), daytime sleepiness (OR:1.28, 95% CI:0.98–1.67). Discussion This study estimates prevalence and risk of neurological complications associated to COVID-19 vaccines, improving vaccination guidelines and loading in future to personalized preventive medicine.