Project #63:
Short-term safety of COVID-19 vaccines in England 2020/21 - neurological events

Safe and effective vaccination is vital for the public health response to the COVID-19 pandemic. The COVID-19 pandemic prompted rapid vaccine development and roll-out. Each vaccine demonstrated a reassuring safety profile in large clinical trials before licensing for use. However, post-licensing vaccine safety surveillance remains important for vaccine safety and public confidence. This study aims to investigate for any association of COVID-19 vaccination with each of Guillain-Barré syndrome, transverse myelitis and Bell’s palsy.

Primary analysis will use a self-controlled case series (SCCS) design, a case-only design which compares incidence of events within the same individual across different time periods. A separate analysis will be conducted for each combination of vaccine brand and outcome. Vaccination status will be obtained from the primary care record. We will use primary care and hospital admission records to define episodes of Guillain-Barré syndrome, transverse myelitis and Bell’s palsy, and will additionally use emergency care attendance data to enhance ascertainment of Bell’s palsy.

We also plan to follow with a secondary analysis using a cohort study design with both historical and concurrent comparator groups. A cohort study design can be a useful complement to investigate the robustness of findings from SCCS analysis in safety studies, since they have a different profile of biases. We will use this analysis to explore the effect of study design on estimates of vaccine safety.

This study is a partnership between the OpenSAFELY collaboration, the NIHR Health Protection Research Unit (HPRU) in Vaccines and Immunisation (a partnership between the London School of Hygiene and the UK Health Security Agency),the NIHR HPRU in Emerging and Zoonotic Infections at University of Liverpool, and the Medicines and Healthcare products Regulatory Agency (MHRA).