Rotavirus vaccine clinical trials: a cross-sectional analysis of clinical trials registries

Rotavirus is a primary infectious virus causing childhood diarrhoea and is associated with significant mortality in children. Three African countries (Nigeria, the Democratic Republic of Congo, and Angola) are among the five countries that account for 50% of all diarrheal-related deaths worldwide. This indicates that much needs to be done to reduce this burden. The World Health Organization International Clinical Trial Registry Platform (WHO ICTRP) is a global repository for primary registries reporting on clinical trials. This study aimed to identify and describe planned, ongoing, and completed rotavirus vaccine trials conducted globally.

We searched WHO-ICTRP on 17 June 2021 and conducted a cross-sectional analysis of rotavirus studies listed in the database. Data extraction included trial location, participant age, source of the trial record, trial phase, sponsor, and availability of results. We used the Microsoft Excel 365 package to generate descriptive summary statistics.

We identified 242 rotavirus vaccine trials registered from 2004 to 2020. Most of these trials were registered retrospectively, with only 26% of the rotavirus vaccine trials reporting the availability of results in their registries. Most of the trials are studying children aged less than 5 years. The recruitment status for these trials is currently shown in the WHO-ICTRP as "not recruiting" for 80.17% of trials, "recruiting" for 11.57% of trials recruiting, and unknown for 6.61% of trials. The continents in which these rotavirus vaccine trials have recruitment sites in Asia (41%) and North America (20%), with the maximum number of trials in the clinical trial registries coming from India (21%) and the USA (11%) with most being sponsored by the pharmaceutical industry. Our analysis shows that only 26% of the rotavirus vaccine trials report the availability of results in their registries.

Mapping rotavirus vaccine clinical trial activity using data from the WHO ICTRP beneficial provides valuable information on planned, ongoing, or completed trials for researchers, funders, and healthcare decision-makers. Despite the high rotavirus disease burden in low- and middle-income countries, including Africa, there is minimal clinical trial activity related to the condition on the continent. The clinical trial registries as a valuable tool to share interim results of the trials.