The original QCovid tool was developed to inform policymakers on the risk of COVID-19-related death or hospital admission for different groups of people, and to help identify patients at high risk of severe COVID-19 outcomes. In their BMJ (British Medical Journal) article, the team of researchers behind QCovid publish two new risk algorithms, QCovid2 and QCovid3, which estimate the risk of COVID-19 related mortality and hospital admission in UK adults after one or two doses of COVID-19 vaccination.
The new risk algorithms were developed based on data from the second pandemic wave in England, analysing data on people who received a vaccination between early December 2020 and June 2021. In total, data from 6,952,440 people were analysed, 74% of whom had received two doses of COVID-19 vaccination. Of 2031 COVID-19 deaths that occurred during the 6-month period, 81 deaths (4%) occurred two weeks or more after the second vaccination dose. People who had received two vaccine doses were over 80% less likely to die from COVID-19 compared to people who had only received one dose.
Closer evaluation of the data showed that particular groups may be at higher risk of COVID-19 mortality and hospital admission after vaccination, in particular people with Down's Syndrome (12.7-fold higher risk), people who had received kidney transplants (8.1 fold higher risk) and people living in care homes (4.1-fold higher risk). Dementia was also associated with a 2.2-fold higher risk of death from COVID-19 after vaccination. Similar patterns of increased risk were observed for the likelihood of hospital admission due to COVID-19. It is hoped that the new QCovid algorithms will help support public health policy and prioritise patients for targeted, early interventions to avoid COVID-19 mortality and hospital admission after vaccination.