PATH’s Center for Vaccine Innovation and Access

Pneumonia: pneumococcus

New pneumococcal vaccines tailored for children that need them most

Photo: Aurelio Ayala III

Photo: Aurelio Ayala III

Pneumonia is the leading cause of death in children less than five years old in the developing world. Each year, close to one million children die from pneumonia, mostly in low-resource countries. The most common cause of severe pneumonia is the bacterium Streptococcus pneumoniae (pneumococcus). Pneumococcus also causes sepsis (blood infection) and meningitis (brain infection), which kill and disable children worldwide. It is also one of the leading causes of bacterial otitis media (middle ear infection). Vaccines are a critical tool for protecting children from this deadly disease.

Pneumococcus has more than 90 serotypes, which vary by region. Current pneumococcal conjugate vaccines (PCVs) are effective against serotypes included in the vaccines, but do not protect against all pneumococcal serotypes. They are also complicated and relatively expensive to produce, making it difficult for poorer countries in most urgent need to afford them without assistance. While Gavi, the Vaccine Alliance and other groups have responded by funding the introduction of current pneumococcal vaccines in low-income countries, new vaccines are needed that are more affordable and can provide either focused protection for children against strains prevalent in the developing world or broad protection across all pneumococcal strains.

To meet this need, PATH is taking a two-pronged approach to accelerate the development of new pneumococcal vaccines that will be effective, affordable, and sustainably accessible in the countries that most urgently need them.

Development of new, affordable PCVs

We are collaborating with the Serum Institute of India, Pvt., Ltd (SIIPL), to speed the development of a 10-valent PCV candidate that focuses on serotypes prevalent in Africa and Asia. This PCV is designed to be more affordable than the currently licensed vaccines. The approach combines efficient conjugation methods with high-yield manufacturing innovations that enable rapid and cost-effective vaccine development. PATH is currently evaluating the vaccine candidate in mid-stage clinical studies in The Gambia. In parallel, the 10-valent PCV is also being evaluated in clinical studies sponsored by SIIPL in India.

Toward broadly protective vaccines

Vaccines that contain proteins common to essentially all pneumococcus serotypes could potentially offer broad, affordable protection to children worldwide and be accessible over the long term. PATH and Boston Children’s Hospital are collaborating with other partners to advance the development of an inactivated, pneumococcal whole cell vaccine candidate (PATH-wSP), which is protein-based and could provide broad protection across the many pneumococcal serotypes. It is designed to be inexpensive to produce and administer.

To date, PATH-wSP demonstrated a good safety and immunogenicity profile in early-stage clinical evaluation among healthy adults in the United States. Currently, the vaccine candidate is being evaluated in mid-stage clinical studies in Kenya, which will provide valuable information about its suitability for target populations in Africa and other low-resource settings. PATH is also partnering with PT Bio Farma, a state-owned vaccine manufacturer in Indonesia, to produce the vaccine.

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