The Management of Viral Hepatitis
Canadian Association for Study of the Liver
Proceedings of a consensus conference held in
Montreal, Quebec in March 1999
HEPATITIS B VACCINATION
At present hepatitis B vaccination policies vary by province across Canada. All provinces include some form of universal vaccination, offered either to all newborns, or to adolescents, as well as vaccination of individuals at high risk of acquiring hepatitis B. Since high risk situations are not always adequately identified, there is a risk that some susceptible individuals will not receive vaccination. Strategies aimed at pre-teens fail to protect against horizontal transmission in children who reside in communities where hepatitis B is endemic. Recent data indicate that in endemic countries horizontal transmission is more common than previously recognized. Horizontal transmission has also been shown to occur at a high rate in South East Asian and other immigrant communities in North America(110-112). The objectives of a universal hepatitis B vaccination policy should be to eliminate vertical (mother to child) transmission, as well as horizontal transmission in early childhood. The policies should also protect against hepatitis B risks imposed by environment, behaviours, or occupation.
The vaccination strategy for Canada should be universal vaccination of all neonates, combined with screening of all pregnant women. Newborns of infected mothers should be given hepatitis B immunoglobulin in addition to the vaccine. A catch up program should be instituted for all children and young adults who have not yet been vaccinated. There should be a standardized national policy, so that vaccination is assured for all children when their families move between provinces.
The seroconversion rate after hepatitis B vaccination in healthy young adults is >90% and children >98%. Therefore, serologic testing post-immunization is not recommended routinely. It is recommended, however, for those with continual or repeated exposures. This would apply to infants of infected mothers, sexual partners of chronic carriers and those with occupational exposure. For further details see the Canadian Immunization Guide, Fifth edition, 1998(113).
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