According to the World Health Organization (WHO), pneumonia is responsible for 16 percent of all deaths of children under five years of age, accounting for over 920,000 child deaths in 2015. Although vaccinations are available, they are only effective against certain strains. GPN Vaccines has developed a vaccine that is claimed to be effective against all forms of Streptococcus pneumoniae, and the Australian company has now secured funding to conduct preclinical trials.
Professor James Paton, a director at GPN Vaccines and Director of the University of Adelaide's Research Centre for Infectious Diseases, says that the current pneumococcal vaccine works by targeting the complex carbohydrates that coat the outside of the Streptococcus pneumoniae bacterium, which is the main cause of pneumonia. He points out that this vaccine, which costs more than US$100 a shot, only covers 13 types of these complex carbohydrates, when there are 98 structurally distinct types. And while there are vaccines being developed that are effective against a greater number of strains, there are still some that slip through the cracks.
The new vaccine developed by GPN Vaccines in partnership with The University of Adelaide works by removing the complex carbohydrates that form an outer coating of the Streptococcus pneumoniae bacterium, exposing the surface proteins that are common to all serotypes of the bacteria. The immune system of individuals that have previously been exposed to those surface proteins or vaccinated can mount a defense against the infection.
The vaccine is a proprietary engineered strain of Streptococcus pneumoniae that has been cultured and inactivated by being exposed to gamma rays – hence its name, Gamma-PN. The company has previously conducted pre-clinical studies where intranasal vaccination with Gamma-PN protected animals against lethal pneumococcal sepsis caused by a number of different Streptococcus pneumoniae strains.
Having raised additional funding, the company will now undertake toxicity tests of the "whole bacterial" vaccine, as well as scaling up its clinical grade manufacture ahead of a first-in-human clinical trial.
"The pneumococcus is the biggest bacterial killer on the planet. It's the most common cause of pneumonia, which is responsible for about 20 per cent of deaths from all causes in children under five years in developing countries. Globally, the pneumococcus accounts for about two million deaths a year," says Professor Paton. "Vaccinating people against Streptococcus pneumoniae would help to ameliorate the global challenge of increasing bacterial resistance to antibiotics."
Source: University of Adelaide