Two deaths in Michigan from a Cyclospora outbreak this summer highlight the ongoing crisis of diarrheal disease, which claims over 1 million lives annually, nearly half of them children under five. This preventable suffering disproportionately impacts the world's most impoverished regions, where basic sanitation remains a luxury. A new vaccine candidate, WRSs2, named after the Walter Reed Army Institute of Research, now offers a potential tool against shigellosis, a leading cause of these deaths, after decades of market failure to deliver a solution.
The WRSs2 vaccine was tested jointly at Cincinnati Children's Hospital Medical Center and the Emory Vaccine Center's Hope Clinic in Atlanta. Results published in The Lancet Infectious Diseases this current year showed it was 89% effective at preventing shigellosis in a trial of 108 adults. Half of the participants received the weakened shigella bacteria, while the other half received salt water. Dr. Kawsar Talaat, an infectious disease physician at Johns Hopkins, noted that 81% of the placebo group became sick, making the vaccine's nearly 90% efficacy "remarkable."
A Century of Neglect
Despite over 100 years of research, no Shigella vaccine has ever been licensed. Prior candidates consistently fell short of WRSs2's efficacy; one reached 74% in young adults but failed in younger children, and another Israeli vaccine managed only 28% overall. Dr. Jahangir Hossain of the Gambia Medical Research Council Unit, who has battled shigellosis since the 1990s, first in Bangladesh and now in West Africa, recalled seeing up to 800 diarrheal patients a day at the International Centre for Diarrhoeal Disease Research in Dhaka. This long history of unaddressed suffering underscores the systemic priorities that have left millions vulnerable.
Diarrheal illness stands as the second leading cause of death for children globally, according to Dr. Robert Frenck, co-leader of the WRSs2 trial. Shigella, a common bacterial cause, spreads through contaminated food and water, flourishing in areas where sanitation infrastructure is poor or nonexistent. Chad, for instance, faces a devastating childhood mortality rate, with roughly 1 in 140 children under five dying each year from such diseases.
Who Bears the Cost
Children who contract Shigella often suffer prolonged diarrhea, increased hospitalization, malnutrition, and cognitive impairment, never fully recovering. Dr. Hossain described families traveling one to three hours to reach a clinic, only to find that diagnostic labs common in American hospitals are largely absent in these regions. Treatment relies on antibiotics, but resistance has climbed to over 80% for some medications in certain areas, rendering existing medical interventions increasingly ineffective. This escalating antimicrobial resistance makes a vaccine "especially important," as Dr. Talaat emphasized, noting the emergence of typhoid strains "almost impossible to treat."
The trial volunteers, paid approximately $250 a day for roughly a week, enabled the swift completion of the study. While the vaccine was not without side effects—over half reported headaches and 45% experienced some diarrhea—no one required hospitalization. The authors deemed the safety profile acceptable, acknowledging the need for further work to balance safety and efficacy.
The State's Hand in Research
The involvement of the Walter Reed Army Institute of Research in developing WRSs2 highlights the state's capacity for scientific investment, often channeled through military institutions. This research, while potentially life-saving, emerges from a system that has historically failed to provide basic public health infrastructure to the global working class. The immediate next step, according to all involved, is testing the vaccine in children, particularly in regions where poor sanitation fuels high rates of diarrheal disease. Dr. Talaat stressed the need for a vaccine "safe and effective in children as young as one year of age, or even younger." Dr. Frenck articulated a goal of "really reducing deaths of children in the world," a goal that remains distant for millions living under conditions of systemic neglect.