Knowledge and perception of a clinical trial among the participants: An experience from oral cholera vaccine study in Koshi Province, Nepal.

Clinical trials (CT) have been the cornerstones in developing medicines, vaccines, and new interventions. Despite tremendous efforts, a CT cannot succeed without participants' involvement. Various factors can affect people's attitude and participation in a CT. Hence, this study was conducted to assess the knowledge and perception of a clinical trial among the participants of a CT at B.P. Koirala Institute of Health Sciences, Dharan, Nepal. This was a population-based descriptive cross-sectional study conducted during 2021-2022. Participants involved in a phase III clinical trial were enrolled, and an in-depth interview was conducted using a semi-structured questionnaire. Demographic information, knowledge and perception about CT were assessed, and a descriptive analysis was done. Among 622 participants, the majority were males (321; 51.6%), literate (587; 94.37%), of indigenous ethnic groups (Janajatis 61.4%), and without previous experience of CT (504; 81.1%). The majority had adequate knowledge (566/622; 91%) and positive perception (595/622; 95.7%) of CT. Most participants (467; 75.1%) had participated in CT to get protection from the particular disease from the provided vaccine and (603; 96.9%) believed CT to benefit mankind. Further studies comparing pre- and post-participation knowledge and perception might be helpful for planning and better management of CTs in such settings.

A randomized, observer-blind, controlled phase III clinical trial assessing safety and immunological non-inferiority of Vi-diphtheria toxoid versus Vi-tetanus toxoid typhoid conjugate vaccine in healthy volunteers in eastern Nepal.

Typhoid remains one of the major serious health concerns for children in developing countries. With extremely drug-resistant cases emerging, preventative measures like sanitation and vaccination, including typhoid conjugate vaccines (TCV) remain the mainstay in its prevention and control. Different types of TCVs are being developed to meet the global demand. This report outlines the results from a study done to assess the immunogenicity and safety of Vi-Diphtheria toxoid (Vi-DT) TCV in Nepal. The study was a randomized, active-controlled, immunological non-inferiority and safety study. Eligible participants from Sunsari and Morang districts of eastern Nepal were randomized into 4 study groups (A-D) within 3 age strata (6 months to <2 years, 2 to <18 years, and 18 to 45 years). Groups A to C received a single dose (25 µg) of Vi-DT test vaccine from any of the 3 lots, while group D received the comparator, Typbar-TCV®, Vi-tetanus toxoid (Vi-TT) vaccine (25 µg) in 1:1:1:1 ratio and evaluated at 4 weeks postvaccination with 6 months follow-up. Amongst 400 randomized participants, anti-Vi-IgG seroconversion rates for all age strata in Vi-DT pooled groups (A+B+C) were 100.00% (97.5% CI 98.34-100.00) vs 98.99% (97.5% CI 93.99-99.85) in Vi-TT group (D) at 4 weeks. Comparable safety events were reported between the groups. Three serious adverse events (1 in Vi-DT; 2 in Vi-TT group) were reported during the 6 months follow-up, none being related to the investigational product. Thus, Vi-DT vaccine is safe, immunogenic, and immunologically non-inferior to Vi-TT when analyzed at 4 weeks postvaccination.