Ignite Creation Date:
2024-05-05 @ 11:54 AM
Last Modification Date:
2024-10-26 @ 9:16 AM
Study NCT ID:
NCT00172328
Status:
UNKNOWN
Last Update Posted:
2005-09-15
First Post:
2005-09-12
Brief Title:
Antibody Response and Immune Memory 15-18 Years After HBV Vaccination
Sponsor:
National Taiwan University Hospital
Organization:
National Taiwan University Hospital
Study Overview
Official Title:
None
Status:
UNKNOWN
Status Verified Date:
2004-09
Last Known Status:
RECRUITING
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
Taiwan is an endemic region for hepatitis B Before the implementation of a nationwide vaccination program in 1984 the hepatitis B virus HBV carrier rate in the general population was 15 to 201-2 The major impact of hepatitis B HB infection is its long-term sequelae which may include chronic hepatitis liver cirrhosis and hepatocellular carcinoma3 Perinatal infection accounts for 40-50 of all hepatitis B infections and is responsible for the generation-to-generation transmission of HB virus4 Hepatitis B vaccines both plasma derived and recombinant are highly immunogenic and efficacious5-10 It has been reported that HB vaccine given soon after birth is able to protect infants from perinatal infection and HB infection became the first disease model to show that mother-to-neonate transmission can be interrupted by an effective vaccine11 Taiwan started a national program of HB vaccination since 1984 This program resulted in a significant reduction of the HB carrier rate in children aged below 10 years from 98 before nationwide vaccination to 13 after the program12 It also decreased the incidence of hepatocellular carcinoma in children aged 6 to 9 years from 052 to 013 per 10000013 However the duration of protection provided by the HB vaccine and the proper timing of a booster dose remains unclear Because the HB vaccine is a subunit protein vaccine which contains only HBsAg a limited duration of protection is anticipated The results of several long-term follow-up studies of the protective efficacy of HB vaccination have been published Soon after vaccination protective levels of antibody anti-HBs 10 mIUmL can be detected in the great majority 83-99 of vaccinees5-7 The proportion of vaccinees with protective anti-HBs levels decreases to 75-87 5 years after vaccination and further drops to 50 to 70 10-12 years after1011141519-21 Because of the progressive decline of anti-HBs and the associated increased likelihood of development of new HBV infections some investigators advise the use of a booster vaccination2021 However a preponderance of data indicates that the protective efficacy of the HB vaccine can last for at least 5 to 10 years and a booster before 5 years is not necessary16-182223 By demonstrating significant augmentation of cellular immunity and adequate induction of a protective level of antiHBs 10 mIUml in HBsAg and HBeAg-positive subjects 10 years after HB vaccination we also proved that protection afforded by HB vaccination persisted for no less than 10 years in all vaccineesR Nevertheless the protective efficacy after the period of 10 years remains unknown Knowledge of the duration of protection of HB vaccine and the optimal timing of booster vaccination remains crucial In this study we are going to examine the humoral and cellular immunity and monitored the antibody response following a booster dose of HB vaccine in a group of children whom had been vaccinated 14 years prior to this study
Detailed Description:
None
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None