Nipah virus (NiV) is a deadly zoonotic disease with pandemic potential, prioritized by the World Health Organization for research and vaccine development. Since Bangladesh has faced annual NiV outbreaks and repeated spillovers since 2001, it is likely to be the site of a Phase II vaccine trial. This study explored people's knowledge about NiV and their willingness to participate in a NiV vaccine trial in Bangladesh. We conducted a mixed methods study, collecting qualitative and quantitative data from Mirpur township, Dhaka, and NiV-affected Faridpur District. From December 2021 to November 2022, the team interviewed adult male and female respondents responsible for household treatment and vaccination decisions. The team conducted 66 in-depth interviews and 978 survey interviews. Many in-depth interviewees were aware of NiV and, when asked if they would participate in a NiV vaccine trial, responded with one of three options: willing, unwilling, or would decide later. They were concerned about vaccine safety and side effects when making a decision about participation. In the survey, more respondents from Mirpur township, Dhaka, had heard about a disease transmitted from bats to people (57 %, 272/478 vs. 52 %, 262/500) and were willing to participate in a vaccine trial (45 %, 217/478 vs. 22 %, 111/500) than those from Faridpur. A high number expressed willingness to take an investigational NiV vaccine during an outbreak (Dhaka 75 %, 205/272 vs. Faridpur 81 %, 398/491 Faridpur). We did not find any association between knowledge about NiV and willingness to participate in a NiV vaccine trial. Many respondents expressed willingness to participate in a NiV vaccine trial, especially during an outbreak, suggesting that such a trial may be feasible in Bangladesh. Given concerns about safety and side effects, clear communication on these issues may support informed participation.

Clinical trials conducted in low resource settings of vaccines against unlikely pandemics generate practical barriers to achieving genuine informed consent. Uncertainty over the likelihood of the occurrence of emerging disease threats complicates risk-benefit considerations. We explored how people interpreted the language of a draft consent form for a Phase II trial of a vaccine against Nipah virus (NiV), a lethal bat-borne zoonosis, and assessed their willingness to participate after learning about the trial procedures. We conducted a mixed-methods study collecting data from residents of Dhaka city, and Faridpur District between December 2021 and November 2022. Our qualitative team revised a draft consent form with input from the community, while the quantitative team conducted face-to-face interviews of 978 household heads making vaccine and treatment decisions. We presented the consent form to 20 respondents. They expressed a desire to learn more about NiV disease and sought clarification on the vaccine trial process, use of a placebo, privacy and confidentiality, potential side effects, and compensation procedures. During the quantitative survey, among 328 respondents who indicated a willingness to participate in the vaccine trial, only 1 % (3/328) were familiar with the concept of a placebo. After the quantitative data collection team explained the meaning of a placebo, 61 % (199/328) expressed their willingness to participate in the trial. Our data suggest that obtaining informed consent for vaccine trials against pathogen with pandemic potentials is feasible but requires a commitment to eliciting study participants' perspectives and tailoring study materials to address their concerns and gaps in understanding.

: In low- and middle-income countries, informal healthcare providers are often the first point of contact for pediatric care. The present qualitative study, conducted in Bangladesh, was designed to explore why parents seek pediatric care from informal providers. Through in-depth interviews with 12 parents of children under 5 years of age, key drivers for visiting informal providers were identified, including geographic and financial accessibility, as well as trust and familiarity. Parents expected informal providers to offer them informed and effective treatment but did not have a clear understanding of evidence-based treatment of pediatric diarrhea. Although informal providers may meet families’ immediate needs, they can also undermine formal healthcare visits and follow-ups that are essential to supporting children’s long-term health. The study findings highlight the need for targeted health education to improve parents’ knowledge, awareness, and informed decision-making. Strengthening trust in formal providers and addressing accessibility barriers is essential to improving pediatric health outcomes in low-resource settings.