Decline of hepatitis B carrier rate in vaccinated and unvaccinated subjects: Sixteen years after newborn vaccination program in Taiwan

Abstract

Taiwan was an endemic area for hepatitis B virus (HBV) infection, and related liver diseases cause a significant drain of public resources. To control the endemic, a nation-wide newborn vaccination program was started in 1985. We reviewed the results of the annual survey for HBV surface antigen (HBsAg) performed in freshmen class of two high schools in Hualien, eastern Taiwan, from 1991 to 2001. A total of 10,194 students, most of them 15 years old, were tested for serum HBsAg using enzyme immunoassays. There is a significant trend (P < 0.0001) of decreasing HBsAg carrier rate from 20.3 to 4.4% in males and 14.3% to 2.4% in females, respectively, over 11 years. The HBsAg carrier rate was 16.0-20.3% in students surveyed during 1991-1993 (born more than 6 years before the start of the national vaccination program), which decreased to 7.7-11.9% during 1994-1999 (born 1-6 years before the program). It further declined to 4.7% and 3.4% in 2000 and 2001 (born after the start of the program). The HBsAg carrier rate in male students was significantly higher than that in female students in most of the years. The HBV newborn vaccination program not only successfully prevented most of the perinatal transmission of HBV but also reduced horizontal transmission of HBV to children born up to 6 years before the start of the program. Also, the protection persisted for at least 15 years.

Hepatitis B Virus Translocates across a Trophoblastic Barrier

“…While this implies that most transmission probably occurs perinatally, a clinically significant proportion of neonatal viral infection occurs despite vaccination. Among children vaccinated at birth, a 1 to 5% viral transmission rate is reported (8,9,26,45,64).…”

24 year outcomes of hepatitis B vaccination in Hangzhou, China

“…A decline in the prevalence of chronic HBV infection among vaccinated people has been documented throughout the world, including Hong Kong, Taiwan, Italy, the Gambia, Alaska, and Senegal. 19,[38][39][40][41][42][43][44] In the United States, which implemented routine HepB vaccination in 1991, the incidence of acute hepatitis B among children and adolescents has decreased by 89%. 45 In Taiwan, where routine infant HepB vaccination commenced in 1984, there has been a 75% decrease in the incidence of HCC among children.…”

“…67 Although no data are available to estimate the proportion of a population that must be immune from HBV infection for there to be an effect from herd immunity, recent experience with routine infant HepB vaccination among Alaska Natives and in Taiwan suggest that once HBV transmission is eliminated among young children there is a reduction in infection pressure in the general population. 19,68 The data of hepatitis B cases reported through the China National Notifiable Disease Reporting System were classified into acute and chronic cases. In the current study, we used the data of acute cases to document the effect of hepatitis B vaccination.…”

“…16 Routine hepatitis B vaccine (HepB) vaccination through the national immunization program plays a vital role in decreasing subsequent HBV infection in children. [17][18][19] In order to prevent this serious health problem, a safe and effective HepB has been available in the United States since 1981, and universal vaccination of infants has been recommended since 1991. 20 The first vaccines were plasma-derived, which contained purified HBsAg obtained from the plasma of people with chronic HBV infection.…”

Comparison of long-term immunogenicity (23 y) of 10 μg and 20 μg doses of hepatitis B vaccine in healthy children

“…1 Immunization with hepatitis B vaccine is the best way to prevent HBV infection. 2,3 The immunogenicity of hepatitis B vaccine has been a subject of intense research ever since HBV vaccine was adopted in most areas of the world. 4 Although high levels of seroprotection rates provided by HBV vaccine (both early plasma-derived and current recombinant) have been adequately confirmed, the duration of protection remains largely unknown.…”