Varicella vaccine were vaccinated as children were still protected from varicella." However, since only one out of five Japanese children were vaccinated, the annual exposure of these vaccinees to children with natural chickenpox boosted the vaccinees' immune system. In the United States, where universal varicella vaccination has been practiced, the majority of children no longer receive exogenous (outside) boosting, thus, their cell-mediated immunity to VZV (varicella zoster virus) wanes—necessitating booster chickenpox vaccinations. As time goes on, boosters may be necessary. Persons exposed to the virus after vaccine tend to experience milder cases of chickenpox. Catching "wild" chickenpox as a child has been
National Centre for Disease Control centers in India, which started surveillance of HIV infection in the country. On 30 July 2009, it was named as National Centre for Disease Control. NCDc has eight divisions under it namely Doctors from NCDC had been previously summoned to investigate potential outbreaks of diseases including suspected cases of Pneumonic plague in Punjab in 2002, SARS outbreaks in 2004, meningitis outbreak in Delhi in 2005, and avian influenza in 2006. The NCDC in collaboration with the Centers for Disease Control and Prevention has set up the Global Disease Detection Regional Center in New Delhi, India. This will lead to long-term