The Covid-19 vaccines that have been approved for use have been carefully tested on tens of thousands of participants in clinical trials.
However, these studies have largely excluded people who are older and 80, for many reasons, including safeguarding their health. Still, people in this age group have a high risk of severe Covid-19 or death, or if they contract the SARS-CoV-2 virus.
To shed light on how well the two-dose Pfizer-BioNTech vaccine works in people who are older than 80 in the real world, a team of researchers from the University of Cambridge carried out a post-vaccination immunogenicity study in the elderly population and younger healthcare workers. Immunogenicity refers to how effectively a vaccine can provoke an immune response.