Double doses of chicken pox vaccine most effective: Study

WASHINGTON - Researchers at Yale School of Medicine have found that two doses are better than one, when it comes to vaccinating children against varicella (chicken pox.

In fact, the odds of developing chicken pox were 95 percent lower in children who had received two doses of the vaccine compared with those who had received only one dose.

In the study, Eugene D. Shapiro and his team showed that the effectiveness of two doses is 98.3 percent.

Past studies have suggested that two doses of varicella vaccine are linked to higher antibody levels than one dose, but this is the first study to assess the clinical effectiveness of two doses of the vaccine in the general population.

In a survey Shapiro and his team discovered 71 cases of chicken pox in children ages four and older. None of these children had received two doses of vaccine; 66 (93 percent) had received one dose and five (7 percent) had received no vaccine.

“We weren’t surprised to find that two doses of varicella vaccine are highly effective and are more likely to prevent varicella than a singe dose.

“The findings confirm that, at least in the short term, the policy of routinely administering two rather than one dose of varicella vaccine is sensible. Other countries that are routinely immunizing children with varicella vaccine may consider changing to a two-dose regimen,” said Shapiro

The findings were published in the Journal of Infectious Diseases. (ANI)