Chickenpox, also known as varicella, is a highly infectious disease that most commonly affects children. It is caused by the Varicella-zoster virus and is an airborne disease. It’s incubation period is 10 – 21 days. The disease results in a reddish, itchy rash of blisters. Typically, it first appears on the chest, back and face, and then spreads to the rest of the body. Other symptoms may include increased body temperature, fatigue and headache. It is considered that once you pull through, you will have a lifelong, permanent immunity to this disease. Most commonly, Chickenpox has an optimistic prognosis, however, its symptoms are not always mild and certain complications may occur (most often in newborn children, pregnant women and adults). Most severe complications are pneumonia and encephalitis. In children under the age of 1 year the mortality rate due to Chickenpox complications is 4 times higher compared to children of age 1 – 14 years, in which the mortality rate is 2%. Also, the virus remains in the organism even after the recovery and later in life, when the immune system is compromised, it may cause the development of herpes zoster. The prophylaxis is done through a vaccine, which is a safe and effective method for prevention of the disease and the possible complications. The vaccine contains a live, attenuated strain of the Varicella-zoster virus. Parents need to buy it, if they want their children vaccinated. Two doses of it are injected subcutaneously or intramuscularly in children above the age of 9 months. In babies who are 9 – 12 months old, the second dose is injected after a minimal interval of 3 months. In children of age 1 – 12 years, the second dose is injected after a minimal interval of 1 month. In children above the age of 12 years, the interval between the two doses is 4 – 8 weeks. The application of the vaccine can be combined with other vaccines, such as those against measles, mumps and rubella. If they are not applies together, there must be an interval of at least 1 month between the injection of the different vaccines. There might be short-term adverse reactions, such as irritability, drowsiness, high temperature, rash, redness and swelling around the injection site. Most commonly, they occur after the first dose. Vaccines are not applied in children with immune deficiencies (acute and chronic leukemia, lymphoma, etc.), undergoing immunosuppressive therapy and with acute and severe infectious diseases.