Can GM-CSF augment the efficacy of respiratory vaccines in older people?

Pneumonia vaccines often fail to protect older people because their immune systems respond too weakly. This project will give the pneumococcal vaccine Pneumovax 23 to adults over 60, then measure their antibody, T cell, and lung macrophage responses in both blood and fluid from the lungs. The goal is to generate precise data on exactly how older immune systems respond to a respiratory vaccine—information that currently does not exist. Without this data, researchers cannot calculate the correct sample size for a clinical trial testing whether an immune-boosting molecule called GM-CSF could make the vaccine work better in older people. Pneumonia kills thousands of older adults in the UK each year, and current vaccines leave many unprotected. If the subsequent trial shows GM-CSF boosts vaccine efficacy, it could lead to a straightforward addition to routine vaccination—a molecule already approved for other uses, added to an existing shot. That would reduce hospitalisations and deaths from a preventable infection without requiring a new vaccine from scratch. This project is a necessary preparatory step, not the trial itself, but without it the trial cannot be designed.