Researchers Work on ‘Super Vaccine’ That Guards Against All Strains of Pneumococcal Disease

Gamma-irradiated G-PN increases immune response

A new “super vaccine” with the ability to eliminate all 90 known strains of the world’s deadliest bacterial disease is being developed by a team at the University of Adelaide in South Australia. G-PN, a whole-cell pneumococcal vaccine, is capable of preventing disease caused by all serotypes of pneumococcus (Streptococcus pneumoniae), according to the researchers.

G-PN helps to increase immune responses to pneumococcus because it keeps the antigenic structure of protein surfaces on the bacterium, lead investigator Professor James Paton explained. In addition, G-PN is inactivated by exposure to gamma irradiation, which makes it more effective than other investigational vaccines that use chemical killing.

“Our vaccine is unique because it protects against all strains of the bacterium. It has gone beyond the basic science of antigen discovery,” Paton said. His team’s research was published in Clinical Science.

According to Paton, gamma irradiation is used to target and break down the DNA strands on the pneumococcal bacterium. This ensures that the bug is no longer viable and is unable to replicate. The gamma irradiation also leaves proteins on the surface of the bug intact, which is important because it allows them to be recognized by the immune system.

Professor Paton said additional work was being done to coadminister G-PN with a gamma-irradiated influenza vaccine.

“Once you have the flu, you are more susceptible to pneumococcal disease, and you are more likely to have the disease kill you,” he said. “We have also now found that not only can we prevent all types of pneumococcal serotypes, but when we combine it with the flu vaccine we get even better protection against pneumococcus as well as protection against flu.”

Paton and his team are awaiting the outcome of a funding application, which will help them complete their preclinical studies.

Pneumococcal disease is a bacterial infection that can result in pneumonia, bacteremia/sepsis, otitis media, or bacterial meningitis. According to the World Health Organization, approximately one million children die of the disease every year.

Approximately 90 pneumococcal serotypes have been identified worldwide.

Sources: Medical Xpress; August 17, 2016; and Clinical Science; March 18, 2016.