Effectiveness of Monovalent Rotavirus Vaccine in Mozambique, a Country with a High Burden of Chronic Malnutrition.

Assucênio Chissaque,Luzia Gonçalves,Benilde Munlela,Elda Anapakala,Keith Shaba,Percina Chirinda,Idalécia Cossa-Moiane,Eva D João,Jason M Mwenda,Goitom Weldegebriel,Umesh D Parashar,Nilsa De Deus,Filomena Manjate,Marcelino Garrine,Júlia Sambo,Jacqueline E Tate,Adilson Fernando Loforte Bauhofer,Jerónimo S Langa,Isah Mohammed Bello,Rachel M Burke ,Jorfélia Chilaúle,Arsénio Nhacolo,Inácio Mandomando,Esperança Lourenço Guimarães

doi:10.3390/vaccines10030449

Abstract

Mozambique introduced monovalent rotavirus vaccine (Rotarix®) in September 2015. We evaluated the effectiveness of Rotarix® under conditions of routine use in Mozambican children hospitalized with acute gastroenteritis (AGE). A test negative case-control analysis was performed on data collected during 2017–2019 from children <5 years old, admitted with AGE in seven sentinel hospital sites in Mozambique. Adjusted VE was calculated for ≥1 dose of vaccine vs. zero doses using unconditional logistic regression, where VE = (1 − aOR) × 100%. VE estimates were stratified by age group, AGE severity, malnutrition, and genotype. Among 689 children eligible for analysis, 23.7% were rotavirus positive (cases) and 76.3% were negative (controls). The adjusted VE of ≥1 dose in children aged 6–11 months was 52.0% (95% CI, −11, 79), and −24.0% (95% CI, −459, 62) among children aged 12–23 months. Estimated VE was lower in stunted than non-stunted children (14% (95% CI, −138, 66) vs. 59% (95% CI, −125, 91)). Rotavirus vaccination appeared moderately effective against rotavirus gastroenteritis hospitalization in young Mozambican children. VE point estimates were lower in older and stunted children, although confidence intervals were wide and overlapped across strata. These findings provide additional evidence for other high-mortality countries considering rotavirus vaccine introduction.

Highlights

Rotavirus is the most important cause of moderate to severe gastroenteritis in children under five years old [1]
The Centro de Investigação em Saúde de Manhiça (CISM) Diarrhoeal Disease Surveillance platform was approved by the same Committee under the reference number 209/CNBS/15; IRB00002657
The present analysis describes the “real-world” vaccine effectiveness (VE) of monovalent rotavirus vaccine in Mozambican children hospitalized with acute gastroenteritis (AGE) during 2017–2019

Summary

Introduction

Rotavirus is the most important cause of moderate to severe gastroenteritis in children under five years old [1]. In 2019, about 128,500 deaths by rotavirus were reported worldwide, of which 81.5% (104,733) occurred in sub-Saharan Africa [1]. In Mozambique, the average annual number of deaths due to rotavirus gastroenteritis (RVGE) among children under five from 2017 to 2019 was 1126, and the mortality rate varied from 27 to 19 per 100,000 children [2]. The burden of malnutrition is high in sub-Saharan African countries [7] and in Mozambique, where more than 40% of children less than five years old suffer from chronic malnutrition [8]. Assessing rotavirus vaccine performance in countries with a high burden of malnutrition is important given that this condition may reduce protection in children [6]

Methods

Results

Conclusion