Feroze Ganaie, PhD

Older adults and people with chronic medical conditions (including chronic lung diseases) are at high risk for serious lung infections caused by Streptococcus pneumoniae. Vaccines have greatly reduced these infections, but two serotypes, 19A and 19F, still cause pneumonia and worsening of lung health, even in fully vaccinated patients. These vaccine failures cannot be explained by chemical changes in the bacteria’s sugar coat, called capsule polysaccharide, which is important for disease and vaccine development. We propose that small genetic changes in capsule making or related genes alter capsule physical properties such as length, thickness, amount or distribution. This makes it harder for antibodies to recognize and kill the bacteria. Our work aims to uncover these new mechanisms of vaccine failure. Ultimately, it will guide improved vaccines and strategies to reduce pneumococcal disease burden and improve the overall lung health, especially in high-risk people.