Long-term Rotarix Vaccine Effectiveness in Coastal Kenya, Estimated From Child Hospital Admissions Data From July 2014 to December 2022.
4 affiliations
- 1Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya.
- 2Department of Statistics and Actuarial Science, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya.
- 3Viral Gastroenteritis Branch, Division of Viral Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
- 4Department of Public Health, Pwani University, Kilifi, Kenya.
Abstract
Background
Two doses of Rotarix demonstrated approximately 64% effectiveness against rotavirus hospitalization in Kenyan children 2.5 years postintroduction. We evaluated long-term Rotarix effectiveness and monitored circulating genotypes over its 8.5 years of use in Kenya.Methods
We conducted a test-negative case-control study in coastal Kenya among children admitted to Kilifi County Referral Hospital with diarrhea from July 2014 to December 2022. Eligible children had known Rotarix vaccination status, parent/guardian consent, and rotavirus testing via enzyme-linked immunosorbent assay. Positives were genotyped by sequencing. Rotarix effectiveness was estimated using unconditional logistic regression, adjusting for age, sex, calendar year, seasonality, and nutritional status.Results
Of the 1104 children (median age, 12 months [interquartile range, 8-18 months]) included in the effectiveness analysis, 87% (962/1104) had received 2 doses, 6% (70/1104) 1 dose, and 7% (72/1104) zero doses. Rotavirus was detected in stool specimens of 147 (13%) children. Overall, adjusted 2-dose Rotarix effectiveness was 68% (95% confidence interval [CI], 42%-82%). Effectiveness in children aged <12 months was 83% (95% CI, 62%-93%) compared to 38% (95% CI, -106% to 78%) in children aged ≥12 months. Genotyping of 147 positive samples revealed G3P[8] (66/147 [44.9%]), G1P[8] (32/147 [21.8%]), and G2P[4] (23/147 [15.6%]) to be the most common circulating rotavirus genotypes during the Rotarix vaccination era.Conclusions
Rotarix maintained modest effectiveness in coastal Kenya during its 8.5 years of use. Effectiveness declined in the second year of life onward, probably reflecting a combination of both waning immunity and accumulation of natural immunity among unvaccinated children. Emergence of vaccine heterologous strains emphasizes the need for continued effectiveness surveillance.
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BibTeX
@article{kipkirui2026longterm,
title = {{Long-term Rotarix Vaccine Effectiveness in Coastal Kenya, Estimated From Child Hospital Admissions Data From July 2014 to December 2022.}},
author = {Zadock Kipkirui and Charity Wamwea and Esther N Katama and Robinson Cheruiyot and Martin Mutunga and Agustus Kea and Arnold W Lambisia and D James Nokes and Umesh D Parashar and Jacqueline E Tate and Eunice W Kagucia and Charles N Agoti},
journal = {Open forum infectious diseases},
year = {2026},
month = oct,
doi = {10.1093/ofid/ofag674},
url = {https://europepmc.org/article/MED/42909274},
note = {CC BY},
}
RIS
TY - JOUR
TI - Long-term Rotarix Vaccine Effectiveness in Coastal Kenya, Estimated From Child Hospital Admissions Data From July 2014 to December 2022.
AU - Zadock Kipkirui
AU - Charity Wamwea
AU - Esther N Katama
AU - Robinson Cheruiyot
AU - Martin Mutunga
AU - Agustus Kea
AU - Arnold W Lambisia
AU - D James Nokes
AU - Umesh D Parashar
AU - Jacqueline E Tate
AU - Eunice W Kagucia
AU - Charles N Agoti
PY - 2026
DA - 2026/10/10
JO - Open forum infectious diseases
DO - 10.1093/ofid/ofag674
UR - https://europepmc.org/article/MED/42909274
AB - Background Two doses of Rotarix demonstrated approximately 64% effectiveness against rotavirus hospitalization in Kenyan children 2.5 years postintroduction. We evaluated long-term Rotarix effectiveness and monitored circulating genotypes over its 8.5 years of use in Kenya.Methods We conducted a test-negative case-control study in coastal Kenya among children admitted to Kilifi County Referral Hospital with diarrhea from July 2014 to December 2022. Eligible children had known Rotarix vaccination status, parent/guardian consent, and rotavirus testing via enzyme-linked immunosorbent assay. Positives were genotyped by sequencing. Rotarix effectiveness was estimated using unconditional logistic regression, adjusting for age, sex, calendar year, seasonality, and nutritional status.Results Of the 1104 children (median age, 12 months [interquartile range, 8-18 months]) included in the effectiveness analysis, 87% (962/1104) had received 2 doses, 6% (70/1104) 1 dose, and 7% (72/1104) zero doses. Rotavirus was detected in stool specimens of 147 (13%) children. Overall, adjusted 2-dose Rotarix effectiveness was 68% (95% confidence interval [CI], 42%-82%). Effectiveness in children aged <12 months was 83% (95% CI, 62%-93%) compared to 38% (95% CI, -106% to 78%) in children aged ≥12 months. Genotyping of 147 positive samples revealed G3P[8] (66/147 [44.9%]), G1P[8] (32/147 [21.8%]), and G2P[4] (23/147 [15.6%]) to be the most common circulating rotavirus genotypes during the Rotarix vaccination era.Conclusions Rotarix maintained modest effectiveness in coastal Kenya during its 8.5 years of use. Effectiveness declined in the second year of life onward, probably reflecting a combination of both waning immunity and accumulation of natural immunity among unvaccinated children. Emergence of vaccine heterologous strains emphasizes the need for continued effectiveness surveillance.
SN - 2328-8957
ER -