title: A model immunization programme to control Japanese encephalitis in Viet Nam.
abstract: In Viet Nam, an inactivated, mouse brain-derived vaccine for Japanese encephalitis (JE) has been given exclusively to ≤ 5 years old children in 3 paediatric doses since 1997. However, JE incidence remained high, especially among children aged 5-9 years. We conducted a model JE immunization programme to assess the feasibility and impact of JE vaccine administered to 1-9 year(s) children in 3 standard-dose regimen: paediatric doses for children aged <3 years and adult doses for those aged ≥ 3 years. Of the targeted children, 96.2% were immunized with ≥ 2 doses of the vaccine. Compared to the national immunization programme, JE incidence rate declined sharply in districts with the model programme (11.32 to 0.87 per 100,000 in pre-versus post-vaccination period). The rate of reduction was most significant in the 5-9 years age-group. We recommend a policy change to include 5-9 years old children in the catch-up immunization campaign and administer a 4th dose to those aged 5-9 years, who had received 3 doses of the vaccine during the first 2-3 years of life.
authors.affiliation: National Institute of Hygiene and Epidemiology (NIHE), Hanoi, Viet Nam.
authors.forename: Nguyen Thu
authors.initials: NT
authors.lastname: Yen
authors.affiliation: International Vaccine Institute, San 4-8, Bongcheon-7 dong, Kwanak-ku, Seoul 151-818, Republic of Korea.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: Preventive Medicine Center, HaTay Province, Viet Nam.
authors.forename: Hoang Duc
authors.initials: HD
authors.lastname: Hanh
authors.affiliation: International Vaccine Institute, San 4-8, Bongcheon-7 dong, Kwanak-ku, Seoul 151-818, Republic of Korea.
authors.forename: Na Yoon
authors.initials: NY
authors.lastname: Chang
authors.affiliation: National Institute of Hygiene and Epidemiology (NIHE), Hanoi, Viet Nam.
authors.forename: Tran Nhu
authors.initials: TN
authors.lastname: Duong
authors.affiliation: Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.
authors.forename: Robert V
authors.initials: RV
authors.lastname: Gibbons
authors.affiliation: International Vaccine Institute, San 4-8, Bongcheon-7 dong, Kwanak-ku, Seoul 151-818, Republic of Korea.
authors.forename: Florian
authors.initials: F
authors.lastname: Marks
authors.affiliation: National Institute of Hygiene and Epidemiology (NIHE), Hanoi, Viet Nam.
authors.forename: Nghiem Anh
authors.initials: NA
authors.lastname: Thu
authors.affiliation: National Institute of Hygiene and Epidemiology (NIHE), Hanoi, Viet Nam.
authors.forename: Nguyen Minh
authors.initials: NM
authors.lastname: Hong
authors.affiliation: International Vaccine Institute, San 4-8, Bongcheon-7 dong, Kwanak-ku, Seoul 151-818, Republic of Korea.
authors.forename: Jin Kyung
authors.initials: JK
authors.lastname: Park
authors.affiliation: National Institute of Hygiene and Epidemiology (NIHE), Hanoi, Viet Nam.
authors.forename: Pham Anh
authors.initials: PA
authors.lastname: Tuan
authors.affiliation: Armed Forces Research Institute of Medical Sciences, Bangkok, Thailand.
authors.forename: Ananda
authors.initials: A
authors.lastname: Nisalak
authors.affiliation: International Vaccine Institute, San 4-8, Bongcheon-7 dong, Kwanak-ku, Seoul 151-818, Republic of Korea.
authors.forename: John D
authors.initials: JD
authors.lastname: Clemens
authors.affiliation: International Vaccine Institute, San 4-8, Bongcheon-7 dong, Kwanak-ku, Seoul 151-818, Republic of Korea ; Department of Epidemiology, Fudan University School of Public Health, Shanghai, China.
authors.forename: Zhi-Yi
authors.initials: ZY
authors.lastname: Xu
mesh_terms: D002648:Child; D002675:Child, Preschool; D004672:Encephalitis, Japanese / Q000453:epidemiology* / Q000517:prevention & control*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D017589:Immunization Programs; D015994:Incidence; D007223:Infant; D022321:Japanese Encephalitis Vaccines / Q000008:administration & dosage*; D008297:Male; D015164:Vaccines, Inactivated / Q000008:administration & dosage; D014744:Vietnam / Q000453:epidemiology
chemical_list: D022321:Japanese Encephalitis Vaccines; D015164:Vaccines, Inactivated
keywords: Demonstration project; Effectiveness study; Immunization; Japanese encephalitis; Vaccines