Development of a novel intranasal vaccine against pneumococcal infection in children

Summary

Streptococcus pneumoniae (pneumococcus) is a leading cause of bacterial pneumonia and sepsis in children particularly in LMIC countries. The most cost-effective public health intervention to reduce pneumococcal diseases is vaccination. However, despite the effectiveness of current polysaccharide-based vaccines, invasive pneumococcal disease  still affects significant numbers of people worldwide, due to the increase in cases caused by non-vaccine serotypes. Recent efforts focus on development of vaccines based on protein antigens, as they are likely to induce protection against most serotypes and cheaper to produce. As pneumococcus normally colonizes the nasopharynx, local immunisation via nasal spray potentially provides an alternative effective vaccination strategy which may not only be effective against invasive disease but also against local nasal carriage. Recent studies showed that immune T cell type (Th17) responses are critical in clearing pneumococcus from the nose and we demonstrated that a protein fragment from pneumococcus  strongly activate this Th17 cell. In this project, we aim to develop a novel vaccine based on this protein to be used as an intranasal spray vaccine against pneumococcal infection.  Vaccines as tools to reduce AMR has been well established including the use of pneumococcal conjugate vaccines. New vaccines against multiple serotypes of pneumococcus will likely make an even more significant impact to reduce antibiotic use and AMR. 

Project outcomes

Pneumococcus is a leading cause of bacterial pneumonia and sepsis in humans particularly in LMIC countries. The most cost-effective public health intervention to reduce pneumococcal diseases is vaccination. However, despite the effectiveness of current polysaccharide-based vaccines, invasive pneumococcal disease still affects significant numbers of people worldwide, due to the increase in cases caused by non-vaccine serotypes. Recent efforts focus on development of vaccines based on protein antigens, as they are likely to induce protection against most serotypes and cheaper to produce. Vaccines as tools to reduce antimicrobial resistance (AMR) has been well established including the use of pneumococcal conjugate vaccines. New vaccines against multiple serotypes of pneumococcus will likely make an even more significant impact to reduce antibiotic use and AMR.

We have identified a small pneumococcal protein molecule which activates significant T cell responses that correlate with protection against pneumococcal infection. Together with a vaccine adjuvant, it may become an effective intranasal spray vaccine preventing multiple serotypes of pneumococcal infection in humans.