COVID-19 vaccination and involuntary movements: A longitudinal panel study

Objective: Despite high COVID-19 vaccination rates in many populations, concerns persist about potential adverse events, including concerns about involuntary movements. While case studies have shown occurrences of involuntary movements following COVID-19 vaccination, no systematic studies have explored this association. Our study aims to investigate the relationship between COVID-19 vaccination and involuntary movements. Methods: This study employs a longitudinal panel design. The study population consists of 165,834 responses from a total of 97,537 unique individuals sourced from the BiCoVac cohort, which is a randomly sampled cohort of Danish individuals aged 16 to 65. Data were collected through a combination of questionnaires and national registers, and analyses were conducted using mixed effects logistic regression. Results: Vaccinated individuals had lower odds of reporting involuntary movements compared to non-vaccinated individuals. Although adjustments attenuated the results, a consistent pattern of lower odds was observed among the vaccinated individuals. The strongest association for the first dose was observed in individuals who received the vaccine within the last 4 weeks before reporting symptoms (OR = 0.72 (0.60; 0.85)). For the second dose, the strongest association was found in individuals who received the second vaccine dose more than 4 weeks before reporting symptoms (OR = 0.77 (0.65; 0.91)). Conclusion: The results of the study do not indicate involuntary movements as an adverse reaction to the COVID19 vaccine. These findings support the safety profile of the COVID-19 vaccine concerning involuntary movements and contribute to enhancing public trust in vaccination programs.