Effectiveness of the Viet Nam produced, mouse brain-derived, inactivated Japanese encephalitis vaccine in Northern Viet Nam.

• Main Authors: Florian Marks (Author), Thi Thu Yen Nguyen (Author), Nhu Duong Tran (Author), Minh Hong Nguyen (Author), Hai Ha Vu (Author), Christian G Meyer (Author), Young Ae You (Author), Frank Konings (Author), Wei Liu (Author), Thomas F Wierzba (Author), Zhi-Yi Xu (Author)
• Format: Book
• Published: Public Library of Science (PLoS), 2012-01-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

<h4>Background</h4>Japanese encephalitis (JE) is a flaviviral disease of public health concern in many parts of Asia. JE often occurs in large epidemics, has a high case-fatality ratio and, among survivors, frequently causes persistent neurological sequelae and mental disabilities. In 1997, the Vietnamese government initiated immunization campaigns targeting all children aged 1-5 years. Three doses of a locally-produced, mouse brain-derived, inactivated JE vaccine (MBV) were given. This study aims at evaluating the effectiveness of Viet Nam's MBV.<h4>Methodology</h4>A matched case-control study was conducted in Northern Viet Nam. Cases were identified through an ongoing hospital-based surveillance. Each case was matched to four healthy controls for age, gender, and neighborhood. The vaccination history was ascertained through JE immunization logbooks maintained at local health centers.<h4>Principal findings</h4>Thirty cases and 120 controls were enrolled. The effectiveness of the JE vaccine was 92.9% [95% CI: 66.6-98.5]. Confounding effects of other risk variables were not observed.<h4>Conclusions</h4>Our results strongly suggest that the locally-produced JE-MBV given to 1-5 years old Vietnamese children was efficacious.

Item Description

1935-2727
1935-2735
10.1371/journal.pntd.0001952