Introduction of a single dose of inactivated HAV vaccine at 12 months of age in Argentina markedly reduced the incidence of symptomatic hepatitis A, fulminant hepatitis, and liver transplantation.
Does a single-dose inactivated HAV vaccine at 12 months of age reduce the incidence of symptomatic and fulminant hepatitis A in countries undergoing epidemiologic transition?
A single-dose HAV vaccination strategy in countries undergoing epidemiologic transition is a cost-effective approach to markedly reduce symptomatic and fulminant hepatitis A.
PURPOSE OF REVIEW: Transmission of hepatitis A virus (HAV) infection is primarily fecal-oral. Symptomatic hepatitis, severe disease, and death are more likely to occur when infection occurs at an older age. Improvements in socioeconomic and hygienic conditions have led to a change in its epidemiology worldwide. RECENT FINDINGS: In the last two decades, improved hygiene in several resource-poor countries has led to reduced transmission of HAV, an increase in average age at infection, and, consequently, a paradoxical increase in morbidity and mortality because of hepatitis A. In Argentina, introduction of one dose (instead of the conventional two doses, to reduce costs) of inactivated HAV vaccine at 12-month age in a universal childhood immunization program during such 'epidemiologic transition' has markedly reduced the incidence of symptomatic hepatitis A, and of fulminant hepatitis and liver transplantation caused by HAV infection. The monetary value of medical and nonmedical benefits of this strategy outweighed the expenditure on vaccination. These excellent results were possibly contingent upon a high vaccination coverage. SUMMARY: Resource-poor countries should closely monitor the epidemiology of HAV infection and periodically undertake cost-effectiveness analyses of HAV immunization strategies. This should allow timely identification of epidemiologic transition and introduction of preventive strategies before HAV infection becomes a public health problem.
Aggarwal et al. (Thu,) conducted a review in Hepatitis A. Inactivated HAV vaccine vs. Conventional two doses was evaluated on Incidence of symptomatic hepatitis A, fulminant hepatitis, and liver transplantation. Introduction of a single dose of inactivated HAV vaccine at 12 months of age in Argentina markedly reduced the incidence of symptomatic hepatitis A, fulminant hepatitis, and liver transplantation.