A new World Health Organization (WHO) study published today in eBioMedicine names 17 pathogens that regularly cause diseases in communities as top priorities for new vaccine development. The WHO study is the first global effort to systematically prioritize endemic pathogens based on criteria that included regional disease burden, antimicrobial resistance risk and socioeconomic impact.

The study reconfirms longstanding priorities for vaccine research and development (R&D), including for HIV, malaria, and tuberculosis – three diseases that collectively take nearly 2.5 million lives each year.

The study also identifies pathogens such as Group A streptococcus and Klebsiella pneumoniae as top disease control priorities in all regions, highlighting the urgency to develop new vaccines for pathogens increasingly resistant to antimicrobials.

Too often global decisions on new vaccines have been solely driven by return on investment, rather than by the number of lives that could be saved in the most vulnerable communities. This study uses broad regional expertise and data to assess vaccines that would not only significantly reduce diseases that greatly impact communities today but also reduce the medical costs that families and health systems face.”

Dr. Kate O’Brien, Director of the Immunization, Vaccines and Biologicals Department at WHO

WHO asked international and regional experts to identify factors that are most important to them when deciding which vaccines to introduce and use. The analysis of those p, combined with regional data for each pathogen, resulted in top 10 priority pathogens for each WHO region. The regional lists where then consolidated to form the global list, resulting in 17 priority endemic pathogens for which new vaccines need to be researched, developed and used.

This new WHO global priority list of endemic pathogens for vaccine R&D supports the Immunization Agenda 2030’s goal of ensuring that everyone, in all regions, can benefit from vaccines that protect them from serious diseases. The list provides an equitable and transparent evidence base to set regional and global agendas for new vaccine R&D and manufacturing, and is intended to give academics, funders, manufacturers and countries a clear direction for where vaccine R&D could have the most impact.

This global prioritization exercise for endemic pathogens, complements the WHO R&D blueprint for epidemics, which identified priority pathogens that could cause future epidemics or pandemics, such as COVID-19 or severe acute respiratory syndrome (SARS).

The findings of this new report on endemic pathogens are part of WHO’s work to identify and support the research priorities and needs of immunization programmes in low- and middle-income countries, to inform the global vaccine R&D agenda, and to strategically advance development and uptake of priority vaccines, particularly against pathogens that cause the largest public health burden and greatest socioeconomic impact.

WHO Priority endemic pathogens list

Vaccines for these pathogens are at different stages of development.

Pathogens where vaccine research is needed

• Group A streptococcus
• Hepatitis C virus
• HIV-1
• Klebsiella pneumoniae

 Pathogens where vaccines need to be further developed

• Cytomegalovirus
• Influenza virus (broadly protective vaccine)
• Leishmania species
• Non-typhoidal Salmonella
• Norovirus
• Plasmodium falciparum (malaria)
• Shigella species
• Staphylococcus aureus

Pathogens where vaccines are approaching regulatory approval, policy recommendation or introduction

• Dengue virus
• Group B streptococcus
• Extra-intestinal pathogenic E. coli
• Mycobacterium tuberculosis
• Respiratory syncytial virus (RSV)