Two doses of the Pfizer vaccine provided 97% protection against death with coronavirus in nursing home residents, according to a large study.
Effectiveness against infection ranged from 80% for nursing home staff to 91% for nursing home residents, the research suggested.
The study by the Catalan Institute of Health, the Public Health Secretariat of Catalonia, and the Centre for Statistics in Medicine at the University of Oxford also showed a 95% reduction in hospital admissions for nursing home residents.
The researchers said nursing home residents have been under-represented in existing clinical trials relating to Covid-19 vaccines and that these have not included large enough sample sizes to provide reliable evidence of protection against severe disease or mortality.
Their study, published in The BMJ and looking specifically at the Pfizer/BioNTech vaccine, analysed data from 28,456 nursing home residents, 26,170 nursing home staff and 61,791 healthcare workers in Spain from late December 2020 to late May this year.
There were fewer than five admissions or deaths in each of the nursing home staff and healthcare worker cohorts.
Researchers also found that one dose of the Pfizer vaccine reduced the risk of infection by 47% in nursing home residents, 38% in nursing home staff, and 40% in healthcare workers, and said the results highlight the importance of getting a second jab and being cautious in the period between, especially during the first two weeks after the initial dose.
Dani Prieto-Alhambra, professor of pharmaco- and device epidemiology at the University of Oxford, said: “Nursing home residents are of course very vulnerable and susceptible to severe Covid. However, they were under-represented or even excluded as participants in the previous trials.
“This study confirms that the effectiveness seen in other (typically healthier) people is also seen for this group of special interest.”
He said the study is also important because it used real-world data, and has confirmed results from well-controlled clinical trials.
Dr Carmen Cabezas, health secretary for Catalonia, said: “This study confirms the great value of the ongoing vaccination programmes to reduce Covid-19 transmission and the related healthcare burden and mortality.”
Research published in June as part of the UCL-led Vivaldi study looking at Covid-19 infections in care homes found that the risk of being infected with coronavirus is substantially reduced for up to 10 months after a first infection.
Researchers found that care home residents with a previous infection were 85% less likely to be infected between October last year and February this year than residents who had never been infected.
Staff with past infection were 60% less likely than staff who had not had the infection before, the study suggested.