Effectiveness of monovalent rotavirus vaccine (Rotarix) against severe diarrhea caused by serotypically unrelated G2P[4] strains in Brazil.

Abstract

BACKGROUND. In a Latin American trial, a monovalent G1P[8] rotavirus vaccine showed high efficacy against severe rotavirus diarrhea. Protection was lower against serotypically unrelated G2P[4] strains, which circulated infrequently. This case-control study was undertaken to assess the effectiveness of this monovalent G1P[8] rotavirus vaccine against G2P[4] strains in Brazil. METHODS. Case patients were children with severe G2P[4] rotavirus diarrhea who presented at a hospital in Recife, Brazil, from March 2006 through September 2008. Vaccination rates among case patients were compared with rates among 2 groups of control participants-children with rotavirus-negative diarrhea and children admitted for acute respiratory tract infection (ARI)-to calculate vaccine effectiveness, after controlling for the birth month and year. RESULTS. We enrolled 70 G2P[4] rotavirus-positive case patients with severe diarrhea, 484 rotavirus-negative control participants with diarrhea, and 416 control participants with ARI, aged 6 months. Among children aged 6-11 months, the effectiveness of the vaccine against G2P[4] diarrhea was 77% (95% confidence interval [CI], 42%-91%) and 77% (95% CI, 43%-90%) among the rotavirus-negative control participants with diarrhea and control participants with ARI, respectively. Vaccine effectiveness in children aged 12 months decreased to -24% (95% CI, -190% to 47%) and 15% (95% CI, -101 to 64) among the rotavirus-negative control groups with diarrhea and ARI, respectively. CONCLUSIONS. This monovalent G1P[8] rotavirus vaccine was effective against severe G2P[4] rotavirus diarrhea among children aged 6-11 months. Effectiveness declined among children aged 12 months, which suggests waning immunity.

• Authors: Jailson B Correia, Manish M Patel, Osamu Nakagomi, Fernanda M U Montenegro, Eliane M Germano, Nancy B Correia, Luis E Cuevas, Umesh D Parashar, Nigel A Cunliffe, Toyoko Nakagomi
• Journal: The Journal of infectious diseases (J Infect Dis) Vol. 201 Issue 3 Pg. 363-9 (Feb 01 2010) ISSN: 1537-6613 [Electronic] United States
• PMID: 20047501 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Rotavirus Vaccines

Topics

• Brazil (epidemiology)
• Case-Control Studies
• Child, Preschool
• Diarrhea (prevention & control, virology)
• Female
• Humans
• Infant
• Male
• Odds Ratio
• Rotavirus (classification)
• Rotavirus Infections (epidemiology, prevention & control, virology)
• Rotavirus Vaccines (administration & dosage, immunology)
• Serotyping