Understanding the Challenges of Oral Live Attenuated Rotavirus Vaccines Performance in Low‐ and Middle‐Income Countries: Host, Pathogen, and Environmental Determinants

Rotaviruses have been the foremost cause of acute gastroenteritis in children <5 years old since their discovery in the 1970s. After the introduction of oral live-attenuated rotavirus vaccines nearly two decades ago, rotavirus vaccination programs have been established in over half of the countries in the world, as they have demonstrated a remarkable impact on reducing disease-associated hospitalizations and mortality rates. Nevertheless, rotavirus continues to claim thousands of children's lives globally each year, with the majority of these fatalities occurring in sub-Saharan Africa and Southeast Asia. Furthermore, while rotavirus vaccines have proven highly effective in high-income settings, their efficacy has been noticeably stunted in low- and middle-income countries. The present study will provide a comprehensive review of a wide range of factors in the triad of host, pathogen, and environment that have been identified or proposed as contributing to these discrepancies in rotavirus vaccine efficacy to better understand and subsequently, improve rotavirus vaccine performance.