Longitudinal assessment of an Ebola vaccine trial understanding among healthcare providers in the Democratic Republic of the Congo

• Published in: Vaccine Vol. 42; no. 3; pp. 481 - 488
• Main Authors: Zola Matuvanga, Trésor, Larivière, Ynke, Lemey, Gwen, Isekah Osang'ir, Bernard, Mariën, Joachim, Milolo, Solange, Meta, Rachel, Matangila, Junior, Maketa, Vivi, Mitashi, Patrick, Van geertruyden, Jean-Pierre, Muhindo-Mavoko, Hypolite, Van Damme, Pierre
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 25.01.2024; Elsevier Limited
• Subjects: Assessment; Binomial distribution; Clinical trial participants; Clinical trials; Comprehension; Consent form; Democratic Republic of the Congo; Ebola Vaccines - adverse effects; Ebola virus; Ethics; Generalized linear models; Health care; Health Personnel; Hemorrhagic Fever, Ebola - prevention & control; Humans; Informed Consent; International organizations; Medical personnel; Participation; Quality control; Questionnaires; Retention; Test of understanding; Vaccines; Variables; Volunteers; Democratic Republic of the Congo; Informed consent; Comprehension; Test of understanding; Clinical trial participants; Assessment; Consent form
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/j.vaccine.2023.12.076

•Research participants and patients undergoing medical procedures may not always comprehend the research protocol accurately.•This is especially pertinent in vaccine trials, as participants need to maintain their understanding and consent form over extended periods.•Researchers suggest evaluating study participants’comprehension before obtaining informed consent.•This study aimed to evaluate participants’ retention of trial information after two years of participation. The long-term retention of information disclosed during the informed consent in clinical trials lasting over a year cannot be guaranteed for all volunteers. This study aimed to assess the level of participants’ retention and understanding of the trial information after two years of participation in a vaccine trial. In total, 699 health care providers (HCPs) and frontline workers were enrolled in the EBL2007 vaccine trial conducted between February 2019 and September 2022 in the Health District of Boende, Democratic Republic of the Congo (DRC). Individual scores obtained from a questionnaire (test of understanding, TOU), specifically designed to assess the understanding of the consent at baseline, were collected before the clinical trial started and at one-year and two-year intervals. TOU scores were high in the beginning of the trial (median TOU = 10/10), but significantly decreased in both the first and second years following (median TOU = 8/10 in year 1 and median TOU = 9/10 in year 2, p-value < 0.0001). The decrease in scores was significantly higher among individuals with occupations requiring shorter education such as midwives (median TOU = 7/10 in year 1 and 8/10 in year 2, pvalue = 0.025). Furthermore, older participants exhibited poorer retention of information compared to younger individuals (median TOU = 8/10 vs 9/10, p-value = 0.007). We observed a significant decline in the informational knowledge of informed consent, specifically in terms of basic knowledge on the study vaccine and trial procedures. As participant safety and understanding is a paramount ethical concern for researchers, it is crucial for participants to fully comprehend the study's objectives and potential risks. Therefore, our findings suggest the need for clinical researchers to re-explain participants to optimize the protection of their rights and wellbeing during the research.