Young Children In Argentina Demonstrate Immune Response To Inactivated HAV Vaccine.(hepatitis A virus)

2001 MAR 14 - (NewsRx.com & NewsRx.net) --

by Sonia Nichols, staff medical writer -- Researchers at a children's hospital in Argentina report children are appropriately protected by an inactivated hepatitis A vaccine.

To prevent hepatitis A virus (HAV) transmission in areas where the disease is highly endemic, public health officials often recommend vaccinating children, who frequently serve as reservoirs for the virus.

E.L. Lopez and others at the Ricardo Gutierrez Hospital for Children in Buenos Aires examined the effects of giving children, 12-months to 15-years-old, half-strength dosages of an adult inactivated hepatitis A vaccine. Five hundred and thirty children received two doses of the vaccine at six-month intervals. One hundred and twenty children were tested for immune response at designated time periods, and all children were assessed for signs of serious adverse effects.

"Two weeks after the first vaccine dose, >99% of initially seronegative children had seroconverted (titers greater than or equal to 20 mIU/ml), with a geometric mean titer of 98.5 mIU/ml," said Lopez et al.

By the time the children received their booster dose, all of them had seroconverted, researchers noted.

The second dose of vaccine raised the children's immune response significantly, with geometric mean titers increasing more than 35 times ("Safety and immunogenicity of a pediatric formulation of inactivated hepatitis A vaccine in Argentinean children," Pediatric ...