Two-dose vaccination program cuts varicella incidence

(HealthDay)—There have been declines in varicella incidence during the first five years of the two-dose vaccination program, according to a study published online Oct. 7 in Pediatrics.

Stephanie R. Bialek, M.D., M.P.H., from the U.S. Centers for Disease Control and Prevention in Atlanta, and colleagues examined varicella incidence rates and disease characteristics in two varicella active surveillance areas—Antelope Valley (AV), Calif., and West Philadelphia—from 1995 to 2010 to assess the impact of the two-dose vaccination program.

The researchers found that the varicella incidence was 0.3 cases per 1,000 population in AV and 0.1 cases per 1,000 population in West Philadelphia in 2010, a decline of 76 and 67 percent, respectively, since 2006 and a 98 percent decline at both sites since 1995. Incidence declined for all age groups from 2006 to 2010, during which time 61.7 percent of case patients in both surveillance areas had been vaccinated with one dose of varicella vaccine and 7.5 percent had been vaccinated with two doses. From 2006 to 2010, varicella-related hospitalizations declined compared with 2002 to 2005 (>40 percent) and 1995 to 1998 (>85 percent). The number of outbreaks in AV also declined: 12 during 2007 to 2010 compared with 47 during 2003 to 2006 and 236 during 1995 to 1998 (P < 0.01).

"Varicella incidence, hospitalizations, and outbreaks in two active surveillance areas declined substantially during the first five years of the two-dose varicella vaccination program," the authors write.