Pneumococcal disease affects mainly the young and the elderly. Current vaccines target the most prevalent variants of the bacteria causing disease, Streptococcus pneumoniae. S. pneumoniae kills half a million under 5-year-olds every year and is the leading cause of pneumonia mortality globally. EU support, under the PnuBioVax project, enabled ImmunoBiology Ltd (ImmBio) to conduct a feasibility study into the commercialisation of its PnuBioVax (PBV) vaccine. PBV was developed to protect against pneumococcal disease and has been tested in a Phase I human clinical study where it was found to be safe and able to activate the immune system. PBV was recently licensed to the largest Chinese vaccine manufacturer, CNBG, part of Sinopharm, covering co-development and commercialisation of the vaccine in China.
Vaccine mimics nature’s immunity
Current vaccines, especially polysaccharide conjugated vaccines (PCVs), very effectively prevent disease caused by the variants contained in the vaccine. However, cases from variants not contained in the vaccine have been on the rise. According to the European Centre for Disease Prevention and Control (ECDC), there has been a continuous increase in invasive pneumococcal disease since 2014. There were 23 886 reported cases in the EU in 2017 alone. It is estimated that 70-75 % of the cases were caused by variants not contained in current vaccines. PBV is created using a strain of S. pneumoniae (TIGR4) that has the toxin pneumolysin-Ply, which plays a role in the virulence of the disease. Although inactivated, this remains immunogenic. In the manufacturing process, the bacteria are subjected to stresses similar to those they experience within the human body. When exposed to these stresses, they increase the production of common proteins. The reaction occurs across all variants of the bacteria associated with the virulence of the disease. The bacteria are then killed and the proteins on the surface of the bacteria harvested and purified. This creates a vaccine which aims to protect against all variants of the bacteria. The vaccine has been tested in a Phase I double-blind study, where 36 subjects (18 to 40 years’ old) were randomised to receive three doses of PBV, 28 days apart, at one of three dose levels (50, 200, 500 µg or placebo). The study showed no serious adverse events (SAE) and only common systemic vaccine-related adverse events (AE) such as mild injection site reactions. The vaccine elicited a dose-dependent response, with a strong induction of antibodies against virulence factors across multiple variants. There was also an increase in pneumococcal killing activity when comparing the PnuBioVax’s 500 µg and 200 µg groups with placebo. As manufacturing costs are anticipated to be lower than EUR 1 per dose, PBV could become a game changer in combatting pneumonia, especially benefiting low- and middle-income countries. “Its multi-protein composition allows an individual’s immune system to personalise their immune response by selecting those proteins in the vaccine that trigger their most effective immune response. “This means PBV will target all strains, including those that are antibiotic-resistant,” says Enrique Tabares, CEO of ImmBio and project coordinator. To introduce PBV into the market, ImmBio is seeking funding for a Phase II Clinical Study at the EHPC unit at Royal Liverpool University Hospital to further validate the vaccine’s efficacy.
PnuBioVax, vaccine, disease, immune, Pneumococcal disease, Streptococcus pneumoniae, pneumonia, toxin, bacteria, antibiotic, proteins