Effectiveness of vaccination with the pentavalent rotavirus vaccine in Nicaragua as determined using the screening method

Abstract

The screening method is a surveillance tool to evaluate vaccine effectiveness (VE) using coverage data on cases and available administrative estimates of vaccine coverage in the population. The aim of this analysis was to evaluate the utility and limitations of using the screening methodology to estimate VE, particularly in a developing world country with a high coverage rate, and to compare it with the VE estimates from 2 case-control studies. Using data from 2008, the screening method employed in this study estimated that VE for 3 doses of RV5 among children < 12 mo of age to prevent wild-type severe disease, resulting in hospitalization or emergency department visits, was 92% (95% confidence interval [CI]: 78–100%). Additional sensitivity analysis demonstrated that the point estimates of VE against severe disease ranged from 72% (95% CI: 62–83%) to 92% (95% CI: 78–100%); this range of VE estimates, although wide, is relatively consistent with results reported from 2 case-control studies in Nicaragua for the same time period. When the infrastructure is in place to collect reasonably robust case data, the use of the screening method to estimate VE is possible in the developing world setting. Cases of severe wild-type rotavirus gastroenteritis were obtained through an observational, hospital-based, prospective, surveillance program to assess rotavirus acute gastroenteritis. The proportion of cases vaccinated was estimated using the child’s vaccination card or health record. The proportion of the population vaccinated was estimated using administrative population-based vaccination coverage estimates provided by the Nicaraguan Ministry of Health.

Keywords: :

• rotavirus
• vaccine effectiveness
• pentavalent rotavirus vaccine
• RV5
• screening method

Conflict of Interest

All authors are responsible for the work described in this paper and were involved in at least one of the following: conception, design, acquisition, analysis, statistical analysis, interpretation of data, and drafting the manuscript and/or revising the manuscript for important intellectual content. All authors provided final approval of the version to be published. Anna Cardellino, Shazia Khawaja, and, T. Christopher Mast are employees of Merck and Co., Inc., who may potentially own stock and/or hold stock options in the company. The authors have no other funding or conflicts of interest to disclose.

Acknowledgments

We are indebted to Xingshu Zhu for her statistical programming support on this study and to Tonya Goodman and Karen Collins, Arbor Communications, Inc., Ann Arbor, MI for manuscript preparation and editorial assistance on behalf of Merck Sharp and Dohme Corp., a subsidiary of Merck and Co., Inc. Merck Sharp and Dohme Corp. provided financial support for this study. All authors have completed the ICMJE form for disclosure of potential conflicts of interests.