Expanding the scope of varicella vaccine debated

Researchers say findings support targeting of age groups other than children. But others aren't quite so sure this step is practical.

By Victoria Stagg Elliott, AMNews staff. Sept. 27, 2004.

The 1995 introduction of universal varicella vaccination for children saved millions of dollars by reducing hospitalizations related to chicken pox, even among age groups not targeted to receive the shots, according to a study published in the September issue of Pediatrics.

"With a focus on extensive vaccination of children, we benefit all ages," said Matthew Davis, MD, lead author and assistant professor of pediatrics, internal medicine and public policy at the University of Michigan Health System.

The vaccine is recommended for all children older than 1 year, and the reductions in rate of hospitalizations were most significant among those younger than 4, decreasing from 4.19 per 10,000 people in 1994 to 0.53 per 10,000 in 2001. Reductions were also seen for adults and adolescents who should received the vaccine. For those older than 20, the rate declined from 0.29 per 10,000 in 1994 to 0.08 per 10,000 in 2001. For those ages 10-19, the rate went from 0.37 to 0.09.

Experts did acknowledge, though, that adult and adolescent vaccination is not a focus, leading them to believe that much of the vaccine's benefit among these age groups may have been reaped by people who probably never received it.

"In households that have children, there would be some adults who would be susceptible to chicken pox, and [adults are] more likely to end up in the hospital with more serious disease than children," said Dennis Murray, MD, chief of pediatric infectious disease at the Medical College of Georgia. "We're actually providing herd immunity."