Varicella vaccine, also known as chickenpox vaccine, is a vaccine that protects against chickenpox. Cangene also produces pharmaceuticals that treat Hepatitis B and varicella (chickenpox). Repeated exposure to chickenpox may protect against zoster. In 2013 there were 140 million cases of chickenpox and herpes zoster worldwide. It is primarily used for the treatment of herpes simplex virus infections, chickenpox, and shingles. Notable diseases like smallpox, herpes, and the chickenpox are caused by such DNA viruses. Serial intervals can vary widely, especially for some lifelong diseases (HIV infection, Chickenpox, Herpes). Rarer complications of disseminated chickenpox include myocarditis, hepatitis, and glomerulonephritis. Common human diseases caused by viruses include the common cold, influenza, chickenpox and cold sores. Persons exposed to the virus after vaccine tend to experience milder cases of chickenpox. It usually begins shortly after recovery from a viral infection, such as influenza or chickenpox. The disease chickenpox is caused by the initial infection with VZV. Chickenpox and smallpox could be distinguished by several methods. The MMRV vaccine which also covers chickenpox may be used instead. Most individuals are infected with this virus as children which causes an episode of chickenpox.