The Global Gut Crisis: Severe diarrhea and dysentery remain the leading causes of death among children under five, particularly in low- and middle-income settings. Beyond the immediate danger, diarrhea leads to malnutrition, adversely affecting physical and cognitive development, thereby perpetuating the cycle of poverty.

Rotavirus - A Major Culprit: The discovery of rotavirus in 1973 filled a significant diagnostic gap in childhood diarrhea, revealing it as the cause of 40–50% of severe acute diarrhea cases in young children worldwide ⁽¹⁾. It most commonly affects those between 6 and 24 months old, with nearly every child experiencing at least one infection by the age of five ⁽²⁾. In 2016 alone, rotavirus was responsible for an estimated 128,500 deaths and over 258 million episodes of diarrhea in children under five, with 90% of global diarrheal deaths occurring in sub-Saharan Africa ⁽³⁾.

A Shot at Prevention - The Global Rollout of Rotavirus Vaccines

The introduction of rotavirus vaccines has been a significant milestone in reducing diarrheal morbidity and mortality. As of now, 123 countries have incorporated the rotavirus vaccine into their national immunization programs, leading to a global reduction of approximately 40% diarrheal admissions among children ⁽⁴⁾.

Challenges with oral rotavirus vaccines:  Despite the progress in rotavirus vaccination, several challenges hinder its widespread impact. By the end of 2023, rotavirus vaccines had achieved approximately 55% global coverage, yet nearly 40% of countries in sub-Saharan Africa had not adopted the vaccine, highlighting significant regional disparities in access ⁽⁵⁾. These vaccines have shown higher efficacy in high-income countries, while their impact in low-income nations, where the disease burden is greatest, is still substantial. Passive transfer of maternal rotavirus antibodies, co-administration with oral polio vaccine, malnutrition, environmental enteropathy, and HIV are major factors compromising rotavirus vaccine efficacy in low-income settings ^(6,7).

Ongoing efforts to Tackle Diarrheal Diseases: To improve the efficacy of oral rotavirus vaccines, ongoing research is exploring alternate dosing schedules, such as neonatal administration and booster doses, as well as micro supplementation with zinc and probiotics ⁽⁷⁾. Injectable rotavirus vaccines also hold promise, as they may overcome the challenges associated with the lower effectiveness of oral vaccines in low-income settings. Combination vaccines targeting multiple pathogens, such as rotavirus and norovirus, are also in the pipeline, aiming to provide broader protection. These innovations, alongside improved water, sanitation, and hygiene (WASH) programs, offer hope for significantly lowering the global burden of diarrheal diseases, particularly in low-resource settings where they remain a major threat to child health.

With each vaccine dose, we move closer to a future where no child suffers or loses their life to preventable diarrheal diseases.

By ISID Emerging Leader, Dr. Tintu Varghese, MD, DTM&H

References

1. Bishop R. Discovery of rotavirus: Implications for child health. J Gastroenterol Hepatol. 2009 Oct;24 Suppl 3:S81-85.
2. Parashar UD, Hummelman EG, Bresee JS, Miller MA, Glass RI. Global Illness and Deaths Caused by Rotavirus Disease in Children. Emerg Infect Dis. 2003 May;9(5):565–72.
3. Troeger C, Khalil IA, Rao PC, Cao S, Blacker BF, Ahmed T, et al. Rotavirus Vaccination and the Global Burden of Rotavirus Diarrhea Among Children Younger Than 5 Years. JAMA Pediatr. 2018 Oct 1;172(10):958.
4. Aliabadi N, Antoni S, Mwenda JM, Weldegebriel G, Biey JNM, Cheikh D, et al. Global Impact of Rotavirus Vaccine Introduction on Rotavirus Hospitalisations Among Children Under 5 Years of Age, 2008–16: Findings from the Global Rotavirus Surveillance Network. Lancet Glob Health. 2019 Jul;7(7):e893–903.
5. Burnett E, Parashar UD, Tate JE. Global impact of rotavirus vaccination on diarrhea hospitalizations and deaths among children <5 years old: 2006–2019. J Infect Dis. 2020 Oct 13;222(10):1731–9.
6. Velasquez DE, Parashar U, Jiang B. Decreased performance of live attenuated, oral rotavirus vaccines in low-income settings: causes and contributing factors. Expert Review of Vaccines. 2018 Feb 1;17(2):145–61.
7. Steele AD, Victor JC, Carey ME, Tate JE, Atherly DE, Pecenka C, et al. Experiences with rotavirus vaccines: can we improve rotavirus vaccine impact in developing countries? Hum Vaccin Immunother. 2019 Feb 8;15(6):1215–27.