Understanding Rotavirus Vaccine Efficacy and Effectiveness in Countries with High Child Mortality

Abstract

Rotavirus claims thousands of lives of children globally every year with a disproportionately high burden in low- and lower-middle income countries where access to health care is limited. Oral, live-attenuated rotavirus vaccines have been evaluated in multiple settings in both low- and high-income populations and have been shown to be safe and efficacious. However, the vaccine efficacy observed in low-income settings with high rotavirus and diarrheal mortality was significantly lower than that seen in high-income populations where rotavirus mortality is less common. Rotavirus vaccines have been introduced and rolled out in more than 112 countries, providing the opportunity to assess effectiveness of the vaccines in these different settings. We provide an overview of the efficacy, effectiveness, and impact of rotavirus vaccines, focusing on high-mortality settings and identify the knowledge gaps for future research. Despite lower efficacy, rotavirus vaccines substantially reduce diarrheal disease and mortality and are cost-effective in countries with high burden. Continued evaluation of the effectiveness, impact, and cost–benefit of rotavirus vaccines, especially the new candidates that have been recently approved for global use, is a key factor for new vaccine introductions in countries, or for a switch of vaccine product in countries with limited resources.

Isolation, Propagation and Genotyping of Human Rotaviruses Circulating among Children with Gastroenteritis in Two Egyptian University Hospitals

“…Rotarix ® (GSK Biologicals, Rixensart, Belgium, prequalified in 2009) is an attenuated G1P[8] human RV strain that has demonstrated high vaccination efficacy in Europe and Africa. RotaTeq ® (Merck & Co. Whitehouse, New Jersey, USA, prequalified in 2008) is a bovine human RV reassortant vaccine that has been shown to be effective in the United States, Europe, and Africa [ 14 , 15 ]. Rotavac (Bharat Biotec, Hyderabad, India, prequalified in 2018) and Rotasiil (Serum Institute of India, Pune, India, prequalified in 2018) are two other attenuated vaccines that are only in use in India (both vaccines) and Palestine (Rotavac only) [ 16 , 17 ].…”

Differences in epidemiology of enteropathogens in children pre- and post-rotavirus vaccine introduction in Kilifi, coastal Kenya

“…We have previously reported a temporal increase in prevalence of Rotarix ® vaccine heterotypic genotypes in Kenya post-vaccination (e.g. G2P[ 4 ] and G3P[ 8 ]) [ 44 ]. It has also been reported elsewhere that RVA prevalence increased with age following introduction of vaccines [ 45 ], which might have occurred in this study that included children up to 13-years of age.…”

“…The World Health Organization (WHO) recommended inclusion of RVA vaccines into national immunization programs (NIPs) of all countries in 2009 [ 3 ]. As of November 2021, 114 countries had included rotavirus vaccination into their NIPs [ 4 ]. Kenya included Rotarix ® (GlaxoSmithKline Biologicals, Rixensart, Belgium), one of the WHO pre-qualified rotavirus vaccines, in its NIP in July 2014 [ 3 ], with doses given at 6 and 10 weeks of age.…”

“…Kenya included Rotarix ® (GlaxoSmithKline Biologicals, Rixensart, Belgium), one of the WHO pre-qualified rotavirus vaccines, in its NIP in July 2014 [ 3 ], with doses given at 6 and 10 weeks of age. Based on antigen testing (enzyme immunoassay; EIA), Kilifi County Hospital (KCH), Coastal Kenya, reported a 57% reduction in rotavirus hospitalizations in the first year after vaccine introduction and an 80% reduction in the second year among children < 5-year-olds [ 4 ]. Further, KCH found a 64% Rotarix ® vaccine effectiveness in children aged < 5 years [ 5 ], which is similar to other low-income settings in sub-Saharan Africa [ 5 , 6 ], but lower than high-income settings [ 7 , 8 ].…”

Genomic epidemiology of the rotavirus G2P[4] strains in coastal Kenya pre- and post-rotavirus vaccine introduction, 2012 – 2018

“…In 2009, the World Health Organization (WHO) recommended inclusion of rotavirus vaccines into the national immunization programmes (NIPs) globally [1]. Kenya introduced the WHO pre-qualified Rotarix® RVA (rotavirus group A) vaccine into its NIP in July 2014 [2]. With the increasing uptake of rotavirus vaccines globally, there has been a significant reduction in RVA-associated disease burden, but this virus still caused about 128,500 deaths in 2016 alone [3,4], with the majority of cases occurring in low-income countries [5].…”