The Pfizer/BioNTech and AstraZeneca/Oxford COVID-19 vaccines are as effective at preventing symptomatic illness in people with underlying medical conditions as in the rest of the population, finds a real-world study of more than 1 million at-risk UK residents.In the observational study, published late last week on the khub preprint server, a team led by Public Health England (PHE) researchers mined the electronic medical records of more than 700 general-practice clinics across the country, representing 10% of the population.
They also conducted sentinel antibody testing from December 2020 to May 2021.While the authors noted that advanced age poses the greatest risk of COVID-19–related hospitalization or death, some underlying conditions