New pneummoccoal vaccine tested in first Controlled Human Infection Model study in Malawi

Pneumococcal disease is an infection caused by Streptococcus pneumoniae bacteria. It can cause serious infectious such as pneumonia, meningitis and sepsis.

The current available vaccines are the pneumococcal conjugate vaccines (PCV) that target either 10 or 13 of the most prevalent serotypes.

The introduction of the PCV vaccine has substantially reduced the global burden of pneumonia and sepsis.

However, there are some strains of Streptococcus pneumoniae that are not targeted by the current PCV vaccine including the increasingly prevalent Serotype 3 pneumococcus (SPN3).

SPN3 has increased not only in carriage prevalence but also as a cause of severe invasive pneumococcal disease, both meningitis and pneumonia, world-wide following the introduction of PCV.

This emergence of SPN3 disease is most likely due to suboptimal protection conferred by PCV against this type. Further, SPN3 strains have a high rate of antimicrobial resistance which is itself an emerging global threat.

As a result, research has moved to the creation of a new vaccine that can target the strains PCV cannot.

The Malawi Accelerated Research in Vaccines by Experimental and Laboratory Systems (MARVELS) research group, led by Professor Stephen Gordon from the Centre for Inflammation Research, will test the effect of PnuBioVax (PBV) vaccine in reduction of the SPN3 strain in a controlled human infection model (CHIM) in Malawi.

The trial is the first ever CHIM programme to test a vaccine for efficacy against pneumococcus in Africa. It is part of a £3.2 million Medical Research Council (MRC) funded project being delivered by Infection Innovation Consortium: iiCON, where Professor Gordon is Director of Experimental Medicine.

PBV is an immunogenic and low-cost protein vaccine which has demonstrated a good safety profile in clinical trials.

PBV uses a set of well-studied pneumococcal proteins. By targeting these proteins, it may trigger immune defenses on the lining of the nose and throat to stop the bacteria from settling there. 

The CHIM trial underway in Malawi is testing PBV on young healthy adults.

Over 250 people have now been enrolled. The trial will enrol 416 people in total over the course of 2026 – making it the biggest human challenge trial conducted in the country to date.

The sample group is being vaccinated and then inoculated in their noses to understand if they are carrying a strain of the disease or not. This is then compared to the existing relevant vaccine and a placebo.

Following the trial, the vaccine could have the potential to be taken forward at scale by an industry partner which could develop and deliver a low-cost vaccine at scale – with potential for manufacturing and distribution across Africa. 

If the PBV CHIM study shows promise, we will proceed to manufacture more vaccine and test the prevention of carriage and transmission by children in the community.

Stephen Gordon

Centre for Inflammation Research

MARVELS

iiCON

PCV CHIM trial