WHO Names 17 Pathogens as Top Priorities for Global Vaccine Development

A new World Health Organization (WHO) study published in eBioMedicine last week highlights 17 viral and bacterial pathogens that are major sources of endemic disease around the world and that WHO officials believe should be urgently prioritized for vaccine development. The study marks the WHO’s first global effort to systematically prioritize endemic pathogens with epidemic potential, focusing on regional disease risk, the increasing threat of antimicrobial resistance, and their socioeconomic impact.¹

The study comes as pharmaceutical companies pivot their strategies in response to declining sales of COVID-19 biologics and therapeutics. As the coronavirus pandemic’s acute phase has subsided in recent years, demand for COVID-related pharmaceutical products—once major revenue drivers for Big Pharma—has significantly decreased, prompting drug makers to refocus on other therapeutic areas. Earlier this year, AstraZeneca plc of the United Kingdom withdrew its Vaxzevria COVID shot from the market, citing low consumer demand.²

“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,” said Kate O’Brien, MD, MPH, director of the Immunization, Vaccines and Biologicals Department at WHO. “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.”¹

Global Resurgence Lands Tuberculosis on WHO’s Priority Endemic Pathogens List

A press release from the WHO about the study categorizes the 17 viral and bacterial pathogens into three categories: pathogens where research is needed (Group A streptococcus, Hepatitis C, HIV-1, and Klebsiella pneumoniae), pathogens where vaccines need to be further developed (influenza, Cytomegalovirus, Leishmania, non-typhoidal Salmonella, Norovirus, Plasmodium falciparum (malaria), Shigella, and Staphylococcus aureus), and pathogens where vaccines are approaching regulatory approval, policy recommendation or introduction (Dengue virus, Group B streptococcus, extra-intestinal pathogenic E. coli, Mycobacterium tuberculosis, and Respiratory Syncytial Virus (RSV).¹

A resurgence in recent years has put tuberculosis back on the government’s radar after cases in the U.S. reached the highest level in a decade in 2023, with over 9,600 cases reported—a 16 percent increase from 2022. This rise affected 40 states, reversing the sharp decline seen during the initial COVID period. One factor driving the resurgence is immune-compromising illnesses, which can reactivate latent tuberculosis (LTBI), a dormant type of infection that only becomes symptomatic when the TB bacteria “wake up” in the body.³

WHO Aims For “Universal” Influenza Vaccine as Demand for Flu Shot Declines in U.S. 

The WHO has included influenza on its list of priority endemic pathogens despite the availability of annual flu shots. The decision stems from the need for more effective and long-lasting coverage. Current vaccines are reformulated each year to match circulating influenza strains, but their effectiveness seems to be less effective every year and in general, can vary due to the virus’s rapid mutation. WHO officials hope to facilitate the development of a broadly protective, or “universal,” influenza vaccine that they believe could provide immunity against multiple strains and reduce the need for annual flu shots and theoretically enhance global preparedness against future pandemics.¹

Public health officials expect the influenza vaccine to reduce the risk of hospitalization by 50 percent but this year’s influenza vaccine is only 34 percent effective in reducing the risk of hospitalization. This finding comes from a study conducted across five South American countries during their flu season from March to July earlier this year.⁴

Influenza vaccination rates among Americans have declined post-pandemic according to the U.S. Centers for Disease Control and Prevention (CDC), particularly among Caucasian children and seniors over 65. Nebraska Medicine, a major health network, recently reported that influenza and COVID shot uptake rates among its staff are well below target levels. As of October 21, 2024 the network’s flu shot uptake rates are 30.7 percent and 28.9 percent, with COVID shot rates at just 9.5 percent, falling short of the organization’s goals of 90 percent influenza vaccine compliance with full documentation.^{5 6}

The CDC’s report also highlights a concerning drop in vaccination among health care workers overall, with only 75.4 percent receiving a flu shot and just 31.3 percent getting the updated COVID booster for the 2023-2024 season, especially low in long-term care settings at 65.2 percent.

H5N1 Not On WHO’s Priority List Targeting Pathogens for New Vaccines

The WHO’s global effort to prioritize diseases that affect specific regions works alongside public health officials’ plans to prepare for potential future epidemics or pandemics. This new report identifies and highlights global vaccine research priorities, with a special emphasis on vaccine programs in low and middle-income countries.¹

Despite rising cases and warnings that there is a potential for a HfN1 “bird flu” pandemic, H5N1 is missing from the WHO’s pathogen priority list for new vaccine development. Earlier this year, former CDC director Robert Redfield, MD, warned of an imminent bird flu pandemic, describing it as a matter of “when, not if,” given the H5N1 virus’s spread within U.S. cattle herds and increasing human cases. It is an interesting exclusion in light of publicity this past year about a pathogen public health officials have insisted is capable of crossing species barriers and posing serious public health risks.^{7 8}

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