Vaccine Failure Rate In Segment Of Chinese Population Elucidated.(Brief Article)

2002 JAN 30 - (NewsRx.com & NewsRx.net) -- by Sonia Nichols, senior medical writer - A Chinese investigation of vaccine escape mutants in adults indicates the vaccine failure rate following hepatitis B virus (HBV) immunization in adults is low but still important.

"The majority of such vaccine escape mutants so far reported have been found while studying vertical transmission of HBV; the vaccine failure rate in connection with vaccine escape mutants in adults is not clear at the moment," Chaun He and coauthors noted in the Journal of Gastroenterology and Hepatology.

He and colleagues at Tsukuba University, Ibaraki, Japan, joined investigators at Chiba University, also in Japan, to elucidate the efficacy of HBV immunization in a selected adult population in terms of vaccine failure and the generation of HBV mutants.

"A total of 176 adult restaurant employees in China, who had been vaccinated according to the food epidemic law, were enrolled in a standard vaccination program," He and team described study participants.

Tested for HBV DNA and HBV surface antigen (HBsAg) prior to vaccination, study volunteers received follow-up tests for the same serum markers one year later. "In those infected with HBV, despite having received the HBV vaccine, direct sequencing within the S gene of the amplified samples was conducted," the researchers said. Current HBV vaccines do not prevent infection with HBV carrying mutations in the S gene, ...