Goma

This research focuses on cholera in endemic areas of Africa, particularly in two sites in the Democratic Republic of the Congo (DRC), one urban and one rural. It aims to evaluate how large oral cholera vaccine mass campaigns affect cholera transmission and control over at least two years. The study addresses a critical knowledge gap by measuring the impact of vaccination in areas with a high burden of cholera, helping to inform future cholera vaccine strategies. The project includes three main components: clinical cholera surveillance to track disease incidence in chosen hotspots, serial serological surveys to detect recent cholera infections within the past year, and identification plus follow-up of individuals shedding the cholera bacteria, whether symptomatic or not, including their household members. This protocol specifically covers clinical surveillance and monitoring of individuals with active cholera shedding in the DRC. Participants will be patients presenting at selected cholera treatment centers who meet the case definition and give consent, as well as household members of confirmed cases who agree to participate. Researchers will measure cholera incidence rates after vaccination, monitor how long individuals shed the bacteria, assess secondary cholera cases within households, analyze the genetic diversity of cholera strains, and develop sustainable surveillance methods. The study's total observation period for cholera control impact is at least two years.

Researchers are evaluating whether people in the Democratic Republic of Congo (DRC) who were previously vaccinated with either the Zabdeno/Mvabea4 or Ervebo4 vaccine schedules against Ebola virus can be safely and effectively given booster vaccines. This randomized controlled trial aims to compare the immune responses and safety profiles of homologous (same vaccine) versus heterologous (different vaccine) booster schedules. The study includes adults aged 18 to 50 who received their primary vaccination more than 4 months ago. Participants will be randomly assigned to receive a single booster dose of either the Zabdeno4 or Ervebo4 vaccine. The trial has four groups based on the type of primary vaccination and booster vaccine received. The booster vaccination will be given once, and participants will be followed for 6 months. During this time, blood samples will be collected at specific visits to compare antibody and cellular immune responses against Ebola virus between the different booster schedules. Throughout the study, safety will be closely monitored by recording any adverse events and assessing physical and vital signs. Participants will attend scheduled clinic visits for blood draws and health evaluations. The main outcome measured is the level of Ebola virus-specific antibodies 21 days after the booster dose to determine if the heterologous booster is not inferior to the homologous booster. The total participation period is approximately 6 months, with follow-up to ensure vaccine safety and immune response durability.