Association between COVID-19 vaccination and stroke: a nationwide case-control study in Qatar

Area of Science:

• Epidemiology
• Vaccinology
• Neurology

Background:

• The Coronavirus Disease 2019 (COVID-19) pandemic necessitated rapid vaccine development.
• mRNA vaccines, including BNT162b2 and mRNA-1273, are widely used for COVID-19 prevention.
• Understanding the long-term safety of COVID-19 vaccination is crucial for public health.

Purpose of the Study:

• To investigate the association between COVID-19 mRNA vaccination and the risk of stroke.
• To evaluate stroke risk in relation to different vaccination schedules (single dose, primary series, booster).
• To examine potential associations across different vaccine types and demographic subgroups.

Main Methods:

• A matched case-control study was conducted in Qatar from December 2020 to April 2023.
• 3036 acute stroke cases were matched with 3036 controls from the general population.
• Statistical analyses, including adjusted odds ratios (aOR) and subgroup analyses, were performed.

Main Results:

• Overall adjusted odds ratio for vaccination and stroke was 0.87 (95% CI: 0.75-1.00), indicating no increased risk.
• No significant association was found for single dose (aOR 0.74), primary series (aOR 0.87), or booster doses (aOR 0.91).
• Analyses for BNT162b2 (aOR 0.87) and mRNA-1273 (aOR 0.86) showed no increased stroke risk. Subgroup analyses by duration, demographics, and stroke type also revealed no significant associations, though a non-significant trend for cerebral venous sinus thrombosis was noted.

Conclusions:

• There is no evidence of an increased risk of stroke following COVID-19 mRNA vaccination.
• The findings apply to both short-term and long-term periods post-vaccination, extending beyond one year.
• This study supports the safety profile of mRNA vaccines concerning stroke risk.