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Volume 37, Number 4, August 2004

An open study of inactivated hepatitis A vaccine (VAQTA) in Taiwanese healthy adult volunteers: safety, tolerability, and immunogenicity

Chin-Ying Yang, Chun-Yi Lu, Chin-Yun Lee, Pei-Lan Shao, Chung-Yi Wang, Tsung-Zu Wu, Li-Min Huang
Department of Pediatrics, National Taiwan University Hospital, Taipei, Taiwan, ROC

Received: July 23, 2003    Revised: August 14, 2003    Accepted: December 9, 2003   


Corresponding author:

Li-Min Huang, M.D., Ph.D., Department of Pediatrics, National Taiwan University Hospital, Fl. 7, No. 7, Chung-Shan S. Road, Taipei, Taiwan 100, ROC. E-mail: This e-mail address is being protected from spam bots, you need JavaScript enabled to view it




The safety, tolerability and immunogenicity of inactivated hepatitis A vaccine (VAQTA, Merck and Co. Inc., West Point, PA, USA) were investigated in 28 seronegative healthy adult volunteers. The age range was 25-35 years, and the mean age was 29 years. Two doses of the vaccine, each containing 50 U of hepatitis A virus antigen, were administered into the deltoid region 24 weeks apart. No serious vaccine-related adverse reactions were reported. Four weeks after the first dose, the geometric mean titer (GMT) was 150 mIU/mL, and the seroconversion rate was 100%. Twenty eight weeks after the first dose (4 weeks following the second dose), the GMT was 4576 mIU/mL. This study demonstrated that VAQTA is safe and highly immunogenic in healthy young adults in Taiwan.



Key words:

Hepatitis A, hepatitis A antibodies, inactivated vaccine, toxicity



J Microbiol Immunol Infect 2004;37:216-218.