Using data to improve public health: COVID-19 secondment

The development and wide-scale deployment of COVID-19 vaccines has increasingly decoupled SARS-CoV-2 infection from its most severe sequelae. Each licensed vaccine has followed a pipeline of preclinical and clinical development that is tailored towards establishing its safety and efficacy. However, considerable uncertainty remains regarding the real-world effectiveness of COVID-19 vaccines, and the extent to which this is impacted by comorbidity status, dosing interval, and variants of concern (including those that have emerged since the completion of Phase III efficacy studies). The analysis of electronic health records has the potential to address key questions regarding real-world COVID-19 vaccine effectiveness with unprecedented speed, scale, and precision. In particular, OpenSAFELY is an open-source platform that links the electronic health records of over 58 million individuals in the UK, providing up-to-date information on demography, vaccination status, and SARS-CoV-2 infection and outcome, while preserving patient confidentiality. My secondment will harness the OpenSAFELY platform to address key evidence gaps relating to real-world COVID-19 vaccine effectiveness. First, I will evaluate primary series and booster dose coverage in key risk groups, including individuals affected by chronic kidney disease. Second, focusing on these high-risk groups, I will use retrospective cohorts nested within OpenSAFELY to compare the effectiveness of different primary vaccine schedules (e.g. BNT162b2 vs ChAdOx1-S) and booster regimens (e.g. homologous vs heterologous boosters). Finally, I will explore the impact of several key factors on the strength and durability of vaccine protection, with a particular emphasis on dose interval and natural SARS-CoV-2 infection (including confirmed positive tests occurring before or after vaccination). In doing so, my secondment will harness electronic health records to address important evidence gaps regarding the ongoing COVID-19 vaccine roll-out.