The study is the first global effort to systematically prioritize endemic pathogens based on their regional and global health impact.
It reaffirms long-standing priorities for vaccine research and development (R&D), including for HIV, malaria and tuberculosis – three diseases that together cause nearly 2.5 million deaths each year.
Pathogens such as group A streptococci, which cause serious infections and contribute to 280,000 deaths from rheumatic heart disease, are also emphasized, mainly in lower-income countries.
Another new priority is Klebsiella pneumoniae — a bacterium that was associated with 790,000 deaths in 2019 and is responsible for 40 percent of neonatal deaths from blood infection (sepsis) in low-income countries.
Focus on needs, not profit
The new study supports the goal of ensuring that everyone, everywhere can benefit from vaccines that provide protection against serious diseases.
It aims to shift the focus of vaccine development away from commercial returns to regional and global health needs, said WHO’s Dr. Mateusz Hasso-Agopsowicz, who works in vaccine research.
He explained that in the past vaccine R&D was typically influenced by profitability. As a result diseases that severely affect low-income regions received little attention.
“We hope this represents a critical shift where we want to change the focus from a commercial perspective, the profitability of new vaccines towards the actual health burden so the new vaccine research and development is driven by health burden and not just commercial opportunities,” he said, speaking from Poland.
Advice from experts
To conduct the study, WHO asked international and regional experts what they think is important when prioritizing pathogens for vaccine R&D. Criteria included death, disease and socioeconomic impact or antimicrobial resistance.
“We had asked experts who have expertise in pathogen epidemiology, clinicians, paediatricians, vaccine experts from all the WHO regions, so to ensure that the list and the results we produce really reflect the needs of different populations worldwide.” said Dr. Hasso-Agopsowicz.
Analysis of these preferences, combined with regional data for each pathogen, resulted in the top 10 priority pathogens for each of WHO’s six regions globally.
The regional lists were then consolidated into the global list, resulting in the 17 priority endemic pathogens for which new vaccines are urgently needed.
To promote vaccine research and development, WHO has categorized each pathogen based on the stage of vaccine development and the technical challenges involved in creating effective vaccines.
Dr. Hasso-Agopsowicz said the study is expected to guide future vaccine R&D investments, including by funders, researchers and vaccine developers, but also policy makers as they “can decide whether to introduce these vaccines into immunization programs.”
