The study included almost 30,000 highly vulnerable nursing home residents who were under-represented in previous clinical trials. In addition, more than 26,000 nursing home staff and over 60,000 healthcare workers were studied, with reductions in infections comparable to those seen in nursing home residents.
“This study confirms the great value of the ongoing vaccination programmes to reduce COVID-19 transmission and the related healthcare burden and mortality,” said Dr Carmen Cabezas, Health Secretary for Catalonia. “Our strategy to vaccinate those most at risk first has proven valuable to reduce the impact of COVID-19 on those most likely to suffer severe forms of the disease. In addition, our plan to prioritise those most exposed to the virus, including our healthcare workers, has also proven useful to keep patients and staff safe whilst they care for us.
Dr Prieto-Alhambra, Professor of Pharmacoepidemiology at Oxford and senior author said: “We are collaborating internationally to produce solid evidence on the risk-benefit of COVID vaccines. Linked real world data from Catalonia and other parts of the world is being used for the study of the safety of vaccines. Here, we used linked primary care, hospital, vaccine, and laboratory data from Catalonia to expand our knowledge on their effectiveness in special subpopulations. The observed effects were in line with those seen in previous clinical trials.”
The study, published in the British Medical Journal (BMJ), will be useful to understand the benefits of COVID-19 vaccines beyond well-controlled randomised controlled trials, and in populations under-represented in previous studies to date. Preliminary data with a shorter follow-up and study period had been uploaded in a preprint form, and disseminated to the public earlier this year.