Rotavirus vaccine effectiveness in Latin American and Caribbean countries: A systematic review and meta-analysis.
BACKGROUND
There are two group A rotavirus (RVA) vaccines available worldwide since 2006: monovalent (Rotarix(®), RV1) and pentavalent (RotaTeq(®), RV5). Currently, 16 countries and 1 territory in Latin America and the Caribbean (LAC) have introduced RVA vaccines and since their introduction several impact and effectiveness studies have been conducted in different countries. The purpose of this study was to assess RVA vaccine effectiveness in LAC countries.


METHODS
We conducted a systematic review and meta-analysis of studies in children under-five who were admitted with laboratory-confirmed RVA diarrhea. We searched Medline, WOS, LILACS, Scopus, and other sources from 2006 to October 2013. Two independent evaluators identified the studies that met predefined selection criteria and extracted relevant information according to a protocol. Pooled estimates were obtained with fixed and random-effects models and stratified according to selected effect modifiers.


RESULTS
Of the 806 articles meeting the initial criteria, 8 case-control studies which involved 27,713 participants (6265 cases and 21,448 controls) were included in the final analyses. The pooled estimates were calculated using different types of controls, leading to different degrees of effectiveness. The effectiveness of two doses of RV1 against rotavirus-related hospitalizations ranged from 63.5% (95% CI: 39.2-78.0) to 72.2% (95%CI: 60.9-80.2). Effectiveness ranged from 75.4% (95%CI: 64.6-82.9) to 81.8% (CI 95%:72.3-88.1) among infants <12 months for RV1, and from 56.5% (95%CI: 26.2-74.3) to 66.4% (95%CI: 54.1-75.5) for infants >12 months. The RV5 effectiveness for diarrhea with a Vesikari score >11 in infants 6 to 11 months old ranged from 76.1% (95%CI: 57.6-86.6) to 88.8% (95%CI: 78.3-94.3). Also, it showed 63.5% (95%CI: 29.4-82.6) of effectiveness against G2P [4].


CONCLUSIONS
RVA vaccines consistently showed protection against diarrhea-related hospitalizations in LAC. Results were more robust for RV1. Effectiveness was shown with different types of controls, but appeared somewhat higher with community controls. Effectiveness was higher among infants <12 months and lower in older children.
Comprehensive Family Immunization Project, Pan American Health Organization, Washington, DC, USA. Electronic address: oliveirl@paho.org.
Lúcia Helena
LH
de Oliveira
Brazilian National School of Public Health, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brazil.
Luiz Antonio Bastos
LA
Camacho
Brazilian National School of Public Health, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brazil.
Evandro Silva Freira
ES
Coutinho
Comprehensive Family Immunization Project, Pan American Health Organization, Washington, DC, USA.
Cuauhtemoc
C
Ruiz-Matus
Laboratory of Comparative and Environmental Virology, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, RJ, Brazil.
José Paulo Gagliardi
JP
Leite
D000367:Age Factors; D017691:Caribbean Region / Q000453:epidemiology; D003967:Diarrhea / Q000453:epidemiology / Q000517:prevention & control; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007843:Latin America / Q000453:epidemiology; D012400:Rotavirus Infections / Q000453:epidemiology* / Q000517:prevention & control*; D022243:Rotavirus Vaccines / Q000008:administration & dosage / Q000276:immunology*; D016896:Treatment Outcome; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000276:immunology
C492457:RIX4414 vaccine; C492535:RotaTeq; D022243:Rotavirus Vaccines; D014613:Vaccines, Attenuated
Latin America and the Caribbean region; Meta-analysis; Rotavirus vaccine effectiveness; Rotavirus vaccines