NOVEMBER 1996 MONTHLY NEWLETTER

Georgetown Health Care Center Georgetown Pharmacy

Chicken pox is an extremely contagious disease that is caused by the varicella zoster virus. Among children, chicken pox usually lasts about five days and is associated with fever, weakness, and the presence of skin lesions that cover the body. In healthy children, the disease is typically not severe and complications do not develop. A vaccine against chicken pox has recently been approved for use in the United States.

Most cases of chicken pox occur in healthy children less than nine years of age. However, the disease is usually more severe and the rate of complications much higher for persons more than 15 years of age and for infants less than one year old. Complications may include infection of the skin, sores, pneumonia, and dehydration.

Although only recently approved for use in the United States, the varicella virus vaccine has been used in European countries since 1984. More than 2 million doses of the vaccine have been administered in these countries with no concerns about vaccine safety identified. In clinical trials in the United States in children one to 12 years of age, more than 11,000 persons have been administered the vaccine with few adverse events reported. These have included pain, redness, soreness, and swelling at the injection site in approximately 20% of those studied, fever of more than 102 degrees F in about 15% of patients, and a rash at the injection site in less than 5% of patients. In persons older than 13 years, about 10% developed fever and more problems with the injection site were reported (24 to 33%).

Recommendations of the Advisory Committee on Immunization Practices

The vaccine has been approved for use among healthy children from 12 months to 12 years of age. All children should be routinely vaccinated against the disease at 12 to 18 months of age. Those children who are known to have had chicken pox are not considered to be susceptible to the disease and do not require vaccination. The vaccine may be administered to children at the same time (at different injection sites) as measles-mumps-rubella (MMR) vaccine. The vaccine is recommended for all children who have not had the disease by their 13th birthday, and is approved for use among older healthy adolescents and adults. Certain high risk groups, such as health care workers and those in contact with persons with compromised immune systems, should be vaccinated if they are susceptible.