Scheifele D
Vaccine Evaluation Center, British Columbia's Children's Hospital, Vancouver, Canada.
Pediatr Infect Dis J. 1998 Jul;17(7 Suppl):S35-7. doi: 10.1097/00006454-199807001-00004.
In the 1980s, populations of the United States and Canada exhibited similar and increasing incidence of hepatitis B. Vaccination programs targeted at high risk populations did not impact on overall disease incidence.
Hepatitis B immunization strategies in the United States and Canada were reviewed to determine their impact on vaccination coverage. To reduce the transmission of hepatitis B, divergent vaccination plans emerged within North America. The United States added hepatitis B to its universal infant immunization schedule, and Canada implemented hepatitis B immunization programs for preadolescents (9 through 13 years of age).
To date, both strategies have markedly increased vaccination coverage among the targeted cohort. Hepatitis B vaccination coverage of infants rose from 8% in 1992 to 82% in 1996 in the United States. In Canada, hepatitis B vaccine uptake rates among preadolescents have been high, with all major provinces reporting near or greater than 90% coverage in 1996.
The incidence of acute and chronic hepatitis B in Canada should drop measurably within the decade as these protected preadolescents move into adulthood. In addition, the Canadian vaccine delivery infrastructure allows for the addition of new vaccines targeted for adolescents.
在20世纪80年代，美国和加拿大的乙肝发病率呈现出相似且上升的趋势。针对高危人群的疫苗接种计划并未对总体疾病发病率产生影响。
对美国和加拿大的乙肝免疫策略进行了审查，以确定其对疫苗接种覆盖率的影响。为减少乙肝传播，北美出现了不同的疫苗接种计划。美国将乙肝疫苗纳入其普遍的婴儿免疫接种计划，而加拿大则为青春期前儿童（9至13岁）实施了乙肝免疫接种计划。
迄今为止，这两种策略都显著提高了目标人群的疫苗接种覆盖率。在美国，婴儿的乙肝疫苗接种覆盖率从1992年的8%上升到了1996年的82%。在加拿大，青春期前儿童的乙肝疫苗接种率一直很高，所有主要省份在1996年报告的覆盖率接近或超过90%。
随着这些受到保护的青春期前儿童步入成年，加拿大急慢性乙肝的发病率在十年内应该会显著下降。此外，加拿大的疫苗接种基础设施允许增加针对青少年的新疫苗。
