Impact of rotavirus vaccination on rotavirus and all-cause gastroenteritis in peri-urban Kenyan children

Monday, 11th of September 2017

Vaccine, Volume 35, Issue 38, 12 September 2017, Pages 5217-5223

ApondiWandera^ab ShahMohammad^a MartinBundi^bc SatoshiKomoto^d JamesNyangao^e CyrusKathiiko^a ErickOdoyo^a GabrielMiringu^a KokiTaniguchi^d YoshioIchinose^ab

KEMRI/Nagasaki University, Institute of Tropical Medicine, Kenya Research Station, Nairobi, Kenya

Graduate School of Biomedical Sciences, Nagasaki University, Japan

National Biosafety Authority, Nairobi, Kenya

Department of Virology and Parasitology, School of Medicine, Fujita Health University, Japan

Centre for Virus Research, KEMRI, Nairobi, Kenya

Received 21 June 2017, Revised 24 July 2017, Accepted 26 July 2017, Available online 2 August 2017.

https://doi.org/10.1016/j.vaccine.2017.07.096 Get rights and content

Highlights

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Rotavirus-associated hospitalizations declined by 49.8%.

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Declines in rotavirus hospitalizations were greatest in vaccine eligible children.

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Hospitalizations for all-cause gastroenteritis decreased by 40.2%.

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Changes in strain distribution observed but could not be attributed to vaccine.

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Findings suggest a significant public health impact of rotavirus vaccinations in Kenya.

Abstract

A monovalent rotavirus vaccine (RV1) was introduced into the National Immunization Program in Kenya in July 2014. We examined the impact of the vaccine on hospitalization for all-cause acute gastroenteritis (AGE) and rotavirus-specific AGE and strain distribution at a large referral hospital which serves a predominantly peri-urban population in Central Kenya. Data on rotavirus AGE and strain distribution were derived from ongoing hospital-based AGE surveillance. Hospital administrative data were used to compare trends in all-cause AGE. Pre-vaccine (July 2009–June 2014) and post-vaccine (July 2014–June 2016) periods were compared for changes in hospitalization for all-cause AGE and rotavirus AGE and strain distribution. Following the vaccine introduction, the proportion of children aged <5 years hospitalized for rotavirus declined by 30% (95% CI: 19–45%) in the first year and 64% (95% CI: 49–77%) in the second year. Reductions in rotavirus positivity were most pronounced among the vaccine-eligible group (<12 months) in the first year post-vaccination at 42% (95% CI: 28–56%). Greater reductions of 67% (95% CI: 51–79%) were seen in the second year in the 12–23 months age group. Similarly, hospitalizations for all-cause AGE among children <5 years of age decreased by 31% (95% CI: 24–40%) in the first year and 58% (95% CI: 49–67%) in the second year of vaccine introduction. Seasonal peaks of rotavirus and all-cause AGE were reduced substantially. There was an increased detection of G2P[4], G3P[6] and G3P[8], which coincided temporally with the timing of the vaccine introduction. Thus, introducing the rotavirus vaccine into the routine immunization program in Kenya has resulted in a notable decline in rotavirus and all-cause AGE hospitalizations in Central Kenya. This provides early evidence for public health policy makers in Kenya to support the sustained use of the rotavirus vaccine in routine immunizations.

Abbreviations

RVI

Monovalent Rotavirus Vaccine

RV5

Pentavalent Rotavirus Vaccine

AGE

Acute Gastroenteritis

RVA

Group A rotavirus

GAVI

Global Alliance for Vaccines Initiative

EPI