title: The Success of a Universal Hepatitis B Immunization Program as Part of Thailand's EPI after 22 Years' Implementation.
abstract: Hepatitis B vaccination for newborns was introduced in two provinces in 1988 as part of Thailand's Expanded Program on Immunization (EPI), and extended to the whole country in 1992. Our previous studies showed that children and adolescents who were born after the implementation of this program had a carrier rate of less than 1%, compared with 5-6% before implementation. In 2014 we performed hepatitis B serosurveys among 5964 subjects in the different geographic regions of the country to evaluate the long-term immunogenicity and impact of universal hepatitis B vaccination in newborns as part of the 22-year EPI program, by assessing HBsAg, anti-HBc and anti-HBs seropositivity status. The number of HB virus (HBV) carriers, both children and young adults, who were born after universal HB vaccination was markedly reduced. The carrier rates among the age groups 6 months to 5 years, 5-10, 11-20, 21-30, 31-40, 41-50 and >50 years were respectively 0.1, 0.29, 0.69, 3.12, 3.78, 4.67 and 5.99%. The seropositivity rate for HBsAg in the post-EPI group was 0.6%, whereas in the pre-EPI group it was as high as 4.5% (p<0.001). HBV infection by means of detectable anti-HBc had also drastically declined in the population born after the HB vaccine was integrated into the EPI program. We estimated that the total number of HBV carriers amounted to 2.22 million, or 3.48% of the total population, most of whom are adults. The HB vaccine is the first vaccine shown to be effective in preventing the occurrence of chronic liver disease and hepatocellular carcinoma. Universal vaccination campaign will contribute to the eventual eradication of HBV-associated disease.
authors.affiliation: Center of Excellence in Clinical Virology, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Pathumwan, Bangkok, Thailand.
authors.forename: Nawarat
authors.initials: N
authors.lastname: Posuwan
authors.affiliation: Center of Excellence in Clinical Virology, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Pathumwan, Bangkok, Thailand.
authors.forename: Nasamon
authors.initials: N
authors.lastname: Wanlapakorn
authors.affiliation: Center of Excellence in Clinical Virology, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Pathumwan, Bangkok, Thailand.
authors.forename: Pattaratida
authors.initials: P
authors.lastname: Sa-Nguanmoo
authors.affiliation: Center of Excellence in Clinical Virology, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Pathumwan, Bangkok, Thailand.
authors.forename: Rujipat
authors.initials: R
authors.lastname: Wasitthankasem
authors.affiliation: Center of Excellence in Clinical Virology, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Pathumwan, Bangkok, Thailand.
authors.forename: Preeyaporn
authors.initials: P
authors.lastname: Vichaiwattana
authors.affiliation: Center of Excellence in Clinical Virology, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Pathumwan, Bangkok, Thailand.
authors.forename: Sirapa
authors.initials: S
authors.lastname: Klinfueng
authors.affiliation: Chumphae Hospital, Chumphae, Khon Kaen, Thailand.
authors.forename: Viboonsak
authors.initials: V
authors.lastname: Vuthitanachot
authors.affiliation: Chumphae Hospital, Chumphae, Khon Kaen, Thailand.
authors.forename: Siriporn
authors.initials: S
authors.lastname: Sae-Lao
authors.affiliation: Uttaradit Hospital, Mueang, Uttaradit, Thailand.
authors.forename: Monthana
authors.initials: M
authors.lastname: Foonoi
authors.affiliation: Uttaradit Hospital, Mueang, Uttaradit, Thailand.
authors.forename: Apinya
authors.initials: A
authors.lastname: Fakthongyoo
authors.affiliation: Lablae Hospital, Lablae, Uttaradit, Thailand.
authors.forename: Jamorn
authors.initials: J
authors.lastname: Makaroon
authors.affiliation: Naresuan University Hospital, Mueang, Phitsanulok, Thailand.
authors.forename: Klaita
authors.initials: K
authors.lastname: Srisingh
authors.affiliation: Phra Nakhon Si Ayutthaya Hospital, Phra Nakhon Si Ayutthaya, Thailand.
authors.forename: Duangporn
authors.initials: D
authors.lastname: Asawarachun
authors.affiliation: King Narai Hospital, Mueang, Lop Buri, Thailand.
authors.forename: Somchai
authors.initials: S
authors.lastname: Owatanapanich
authors.affiliation: Narathiwat Ratchanakarin Hospital, Mueang, Narathiwat, Thailand.
authors.forename: Norra
authors.initials: N
authors.lastname: Wutthiratkowit
authors.affiliation: Trang Hospital, Mueang, Trang, Thailand.
authors.forename: Kraisorn
authors.initials: K
authors.lastname: Tohtubtiang
authors.affiliation: Bureau of Epidemiology, Department of Disease Control, Ministry of Public Health, Mueang, Nonthaburi, Thailand.
authors.forename: Pornsak
authors.initials: P
authors.lastname: Yoocharoen
authors.affiliation: Center of Excellence in Clinical Virology, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Pathumwan, Bangkok, Thailand.
authors.forename: Sompong
authors.initials: S
authors.lastname: Vongpunsawad
authors.affiliation: Center of Excellence in Clinical Virology, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Pathumwan, Bangkok, Thailand.
authors.forename: Yong
authors.initials: Y
authors.lastname: Poovorawan
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D006509:Hepatitis B / Q000453:epidemiology* / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D017325:Hepatitis B Vaccines / Q000627:therapeutic use*; D006515:Hepatitis B virus / Q000276:immunology / Q000472:pathogenicity; D006801:Humans; D007114:Immunization; D007223:Infant; D008875:Middle Aged; D013785:Thailand
chemical_list: D017325:Hepatitis B Vaccines