What is the Cytomegalovirus (CMV)?

Cytomegalovirus (CMV) is a member of the herpes virus group, which includes herpes simplex virus and varicella-zoster virus. CMV is spread from person to person by direct contact with body fluids such as blood, urine, or saliva. Children in day care centers usually spread the virus among themselves and then spread it to their family members.

CMV infects between 50% and 85% of adults in the United States by 40 years of age and is the virus most frequently transmitted from a pregnant woman to her child before birth. In children who acquire the virus after birth and adults, CMV is usually a mild disease with a few symptoms and no long-term health consequences.

However, CMV infection poses a risk to the:

Unborn baby during pregnancy, who may have CMV complications, such as hearing loss, visual impairment, or diminished mental and motor capabilities. In fact, CMV is one of the leading causes of deafness in children. For instance, about 8,000 newborns have healthproblems each year asa result of congenital CMV infection.

Immunocompromised person-such as organ transplant recipients and persons infected with human immunodeficiency virus (HIV). In these persons, CMV can lead to pneumonia, retinitis (an infection of the eyes), blindness and gastrointestinal disease.

According to a report from the Institute of Medicine, the development of a vaccine toprevent CMV disease must be a high priority because ofthe economic costs thatwould be avoided and the years of life and disability that would be saved by a successful vaccine.

For example, in the 1990s, CMV infection of unborn babies was estimated to cost the US health care system at least $1.86 billion each year, with a cost per child of more than $300,000.

A potential CMV vaccine is important to prevent death, deafness, and mental retardation due to CMV infection of unborn babies. As to 2004, five CMV vaccine candidates had been or were being tested in humans including alive attenuated vaccine, a DNA vaccine and a recombinant vaccine.

A 2004 study, Congenital Cytomegalovirus Infection and Its Prevention, suggests that CMV infection before pregnancy also puts the fetus at risk-even two years before conception. This risk would make a potential CMV vaccine not only targeted for pregnant women and immunocompromised persons, but also adolescent women, and young married women years before they become pregnant.