Chickenpox Vaccine Update

Recommended two doses of varicella vaccine appear to be highly effective at preventing infection.
The Boston Globe (1/5, Kotz) "Daily Dose" blog reported that when the chicken pox vaccine "was...in its infancy" some 15 years ago, "many parents" had various concerns that led them to "shun the vaccine in favor of getting their children infected 'naturally' with the varicella virus...going so far as to bring them to parties with other infected kids." Now, Yale researchers have released a paper that is said to detail the "first study to assess the effectiveness of the two-dose vaccine in the general population."
The group began their work by performing "a case-control study of children four years and older," MedPage Today (1/5, Neale) reported. "Each child with confirmed varicella infection was matched by age and pediatric practice with up to two healthy controls" and, according to the paper in the Journal of Infectious Diseases, "from July 2006 to January 2010, the researchers enrolled 71 cases and 140 controls."
Investigators eventually noted that "none of the youngsters who came down with the illness had received the two-dose course of the vaccine, while 93 percent had received one dose and seven percent had not been vaccinated," HealthDay (1/5, Holohan) reported. Next, the team "compared children who received two doses of the vaccine to those who received one dose and found that the effectiveness rates were 98.3 percent and 86 percent, respectively. In other words, 'the odds of developing varicella were 95 percent lower in children who had received two doses of the vaccine compared with those who had received only one,'" the study authors explained, adding that their "findings support the CDC's recommendation for the two-dose regimen."