BERGEN, Norway, July 7 (World Daily Times) — Parents and health workers in places where severe diarrhea remains common may one day have another prevention tool, after an experimental oral vaccine against enterotoxigenic Escherichia coli, or ETEC, showed signs of protection in young children in The Gambia, researchers reported in The Lancet Infectious Diseases.
The randomized, placebo-controlled phase 2b trial enrolled about 5,000 children ages 6 to 18 months. Investigators said the vaccine, called ETVAX, triggered antibodies against ETEC colonization factors and heat-labile toxin, and they reported no vaccine-related serious adverse events.
The size of the benefit depended on how the illness was counted. The study reported 26.6% efficacy against the primary endpoint, 48.2% against moderate-to-severe ETEC diarrhea when co-pathogens were included, and 21% against moderate-to-severe diarrhea from any cause.
In children who started vaccination before 9 months of age, efficacy against moderate-to-severe ETEC diarrhea rose to 67.8%, and it reached 80.6% when children with certain intestinal parasites were excluded, according to the study.
The study authors said the results were the first demonstration of protective efficacy by ETVAX in young children at risk and said the findings support a larger multicountry phase 3 trial. A review of ETEC vaccine development in PubMed Central said no licensed ETEC vaccine is available yet and described the pathogen as a major cause of diarrhea in children in low- and middle-income countries.
