Chickenpox, also known as varicella, is a highly contagious disease. A new study shows kids who have been vaccinated and contract chickenpox are half as contagious as those who are not vaccinated.
In a recent study researchers examined chickenpox transmission within households considering the chickenpox history, vaccination status of the primary case, and vaccine effectiveness in preventing secondary attacks. Nearly 320,000 people between 1997 and 2001 were observed .
During the study, 6,316 cases of chickenpox were reported. The study showed among children 1 to 14 years old who were exposed to chickenpox from unvaccinated children, the secondary disease rate was nearly 72 percent. Among the same age group exposed to vaccinated cases, the secondary attack rate was 15 percent. Overall, vaccinated patients were half as contagious as unvaccinated patients. However, vaccinated cases of chickenpox with 50 or more lesions were as contagious as unvaccinated cases.
"Further understanding of the severity and contagiousness of these cases in the community as well as in household settings will assist with further vaccine policy decisions," conclude researchers.