Pneumococcal Vaccination Uptake in People With Immunosuppressed Conditions Using Real-World Primary Care Data Across England: Protocol for a Retrospective Descriptive Study.

Background: The introduction of pneumococcal vaccination programs in the United Kingdom has led to substantial reduction in the burden of pneumococcal disease in the general population, decreasing the incidence of invasive pneumococcal disease and preventing associated mortality. Current UK guidelines recommend pneumococcal vaccination for adults aged ≥65 years, as well as for individuals aged ≥2 years with underlying medical conditions that place them at increased risk of severe pneumococcal disease. This includes adults with immunosuppression. To date, there are few data in the United Kingdom of pneumococcal vaccine coverage in specific high-risk groups, such as those with immunocompromised conditions. Objective: We aim to evaluate the yearly uptake of pneumococcal vaccine in adults who are included in national recommendations as people with immunosuppressive conditions, stratified by etiology of immunosuppression. Methods: This will be a retrospective cohort study with data from the Oxford-Royal College of General Practitioners Research and Surveillance Centre network, which is nationally representative of the English population. The population under study includes adults registered in the Research and Surveillance Centre database with immunosuppression, including those with bone marrow compromise, with solid organ transplant, receiving oncological treatment, using immunosuppressive drugs, or with primary or acquired immunodeficiencies. The exposure is the underlying medical condition leading to an immunosuppression category. The primary outcome will be pneumococcal vaccination, defined as one dose of the 23-valent pneumococcal polysaccharide vaccine (PPV23). Results: The study was funded in May 2025, and data extraction was performed from December 2025 to February 2026. Analysis was started in March 2026, with final results expected to be submited for publication in 2026. We will report pneumococcal vaccine uptake disaggregated for the high-risk group of people with immunosuppressive conditions, which has not been previously reported. We will also report on the socioeconomic gradient for vaccine uptake (through the use of the Index of Multiple Deprivation score and region) and report on the differences among ethnic groups. Conclusions: We will inform on the granularity of routine primary care data to include disaggregated reports of vaccine uptake in the immunosuppressed population in routine surveillance in the United Kingdom. This will aim to address the gap on pneumococcal vaccination coverage in people with immunosuppressive conditions, helping to identify potential unwarranted variations in vaccine adoption.