Shigella vaccine immunity checked years later in african kids

This study follows up on African children who received an experimental Shigella vaccine in earlier studies. Researchers will take blood samples 1, 2, and 3 years after the last vaccine dose to see how long the immune protection lasts. No new vaccines are given in this study. The goal is to understand if the vaccine provides long-term protection against severe diarrhea caused by Shigella bacteria.