Hepatitis A Vaccination Rates and Related Factors in a 2005 Population-based Study in Nonsan, Korea

Abstract

OBJECTIVESThe incidence of clinical hepatitis A has increased in young Korean adults since the mid-1990s. Although hepatitis A vaccinations have been administered in private clinics over the past 10 yr, no data exist on the vaccination rate and relating factors.METHODSIn 2005, a population-based survey of 12-35-month-old children was carried out in Nonsan, Korea. An interview survey was completed for 71.3% of the children. All data came from a vaccination card or confirmation from a provider.RESULTSThe hepatitis A vaccination rate was 42.3% for ≥1 dose and 24.7% for 2-dose. The results of the multivariate regression analysis for the hepatitis A vaccination showed that the second (OR=1.6) and third and successive children (OR=3.3) were less often immunized than the first child. Low economic status (OR=1.6), rural area (OR=1.5) and employed mother (OR=1.5) were also correlated with a lower vaccination rate. The hepatitis A vaccination rate was significantly lower in children who had no other vaccinations: measlesmumps-rubella (OR=2.8 for ≥1 dose and 7.3 for 2-dose), varicella (OR=20.2 and 22.0, respectively) and Haemophilus influenza type b (OR=14.3 and 13.3, respectively).CONCLUSIONTo prevent outbreaks of clinical hepatitis A by enough herd immunity, a vaccination should be included in the National Immunization Program and a vaccination policy developed and implemented that can overcome the barriers to immunization such as late birth order and a mother's employment.

Very low prevalence of anti-HAV in Japan: high potential for future outbreak

“…In Korea, high anti-HAV prevalence of approximately 96% was reported in 1980, and an outbreak affecting a million people has occurred twice in China, in 1983 and 1988. Therefore, Korea and China introduced the HAV vaccine for high risk populations in 1997 22 and 2007 23 , respectively, after which it was included in the national immunization program starting from 2007 for China and 2015 for Korea. As a result, the level of active immunity to HAV via the vaccine increased dramatically.…”

Factors Related to Completed Status and Seropositivity of Hepatitis A Immunization Among Children Aged 1–3 Years and 6–8 Years in South Korea

“…Therefore, there have been several arguments that HAV vaccination must be included in the NIP [19]. The number of people receiving two doses of the hepatitis A vaccine in Korea has been estimated at 41.6% based on the number of hepatitis A vaccines sold between 1998 and 2006 [20] and 24.7% based on a 2005 population-based survey [7]. Unfortunately, our study was not designed to provide hepatitis vaccination rates.…”

“…Results of two studies have confirmed that 50.6% of children have received the hepatitis A immunization [6], and 42.3% have received the first dose whereas only 24.7% have received both doses of the vaccination [7], indicating that there are significant barriers in accessing immunization services. Yun et al conducted a study to investigate the seroprevalence and vaccination rates in Korea [6].…”

Evaluation on the Accuracy of Vaccination Card for National Immunization Program in a 2005 Population-Based Survey in Nonsan, Korea

“…We conducted face-to-face interviews with subjects' guardians and check record of subject's vaccination card from February to April, 2005 [6,7]. We obtained informed consent to subject's guardians after full explanation about this study.…”