# COVID-19 vaccination and major cardiovascular and haematological adverse events in Abu Dhabi: retrospective cohort study

## TL;DR

This study found no increased risk of cardiovascular or blood-related adverse events after receiving either the inactivated or mRNA-based COVID-19 vaccines in Abu Dhabi.

## Contribution

The study provides real-world evidence on the safety of two major COVID-19 vaccines in a large population in the UAE.

## Key findings

- No significant increase in cardiovascular or haematological events was observed within 21 days post-vaccination.
- No elevated risk was found for adverse outcomes after first, second, or third doses of either vaccine.
- Results showed no substantial link between vaccination and higher likelihood of these adverse events.

## Abstract

The widespread administration of COVID-19 vaccines has prompted a need to understand their safety profile. This investigation focuses on the safety of inactivated and mRNA-based COVID-19 vaccines, particularly concerning potential cardiovascular and haematological adverse events. A retrospective cohort study was conducted for 1.3 million individuals residing in Abu Dhabi, United Arab Emirates, who received 1.8 million doses of the inactivated BBIBP CorV (by SinoPharm) and mRNA-based BNT162b2 (Pfizer-BioNTech) vaccines between June 1, 2021, and June 30, 2022. The study’s primary outcome was to assess the occurrence of selected cardiovascular and haematological events leading to hospitalization or emergency room visits within 21 days post-vaccination. Results showed no significant increase in the incidence rates of these events compared to the subsequent 22 to 42 days following vaccination. Analysis revealed no elevated risk for adverse outcomes following first (IRR 1·03; 95% CI 0·82-1·31), second (IRR 0·92; 95% CI 0·72-1·16) and third (IRR 0·82; 95% CI 0·66-1·00) doses of either vaccine. This study found no substantial link between receiving either mRNA and inactivated COVID-19 vaccines and a higher likelihood of cardiovascular or haematological events within 21 days after vaccination.

Adverse cardiovascular and haematological events following COVID-19 vaccination have been reported, leading to safety concerns. Here, the authors find no evidence for increased incidence of these events within 21 days of BIBP-CorV or BNT162b2 vaccination in electronic health record data from Abu Dhabi.