Researchers conducted a randomized controlled trial to test a new oral vaccine called ETVAX. The study involved 4,936 Gambian children aged 6 to 18 months across four enrolment centres. Participants received either the vaccine or a placebo. The main goal was to prevent moderate-to-severe diarrhoea caused by Enterotoxigenic Escherichia coli. This primary goal was not met in the trial.
However, the vaccine showed positive results in several secondary measures. It was linked to a 48.2 percent reduction in diarrhoea regardless of other germs present. When excluding parasites, the link to reduced diarrhoea was even stronger at 80.6 percent. Starting the vaccine before age 9 months also showed a positive link to lower diarrhoea rates.
The vaccine was considered safe with no adverse events related to the product. Serious issues occurred in about 1 percent of children in both groups. Because the main goal was not met, this phase 2b trial supports advancing the vaccine to a larger phase 3 trial to gather more evidence.