Fewer people in the U.S. than ever before die of chickenpox, now that the chickenpox vaccine (search) is part of a child's routine immunization schedule.

Chickenpox, also called varicella (search), is a highly contagious disease that typically strikes in childhood (but can occur at any age).

The most common symptoms are red bumps or a rash that turns into blisters. Chickenpox spreads like a cold and is most contagious from two to three days before the rash develops. Though the disease is usually mild, it can lead to serious and sometimes fatal complications such as severe pneumonia, skin infections, and brain infections. Infection during pregnancy can lead to birth defects.

In 1995, the U.S. launched the world’s first universal childhood varicella vaccination program. Nearly a decade later, experts say the program has sharply cut chickenpox deaths.

Fewer Chickenpox Deaths

The report, published in The New England Journal of Medicine’s Feb. 3 edition, comes from the CDC’s National Immunization Program. Huong Nguyen, MPH, and colleagues analyzed years of death records citing chickenpox as the underlying or contributing cause of death.

Chickenpox killed an average of 145 people per year from 1990 to 1994, says the CDC. That number declined to an annual average of 66 deaths from 1999 through 2001.

That includes deaths for which chickenpox was listed as the underlying or contributing cause. Just looking at deaths listing chickenpox as the underlying cause, overall death rates dropped 66 percent over the same period.

Biggest Improvement for Kids Aged 1-4 Years

Children aged 1 to 4 years had the biggest drop -- 92 percent -- in chickenpox deaths. Declines were also seen in all age groups under 50. Death rates were similar for different racial and ethnic groups.

“Since the implementation of the varicella vaccination program, varicella-related deaths have declined dramatically to the lowest level ever reported,” write the researchers. “Rates of mortality due to varicella in the United States are now considerably lower than the reported rates in countries that do not have a universal vaccination program.”

Chickenpox can strike anytime, but it tends to be most common in the winter and spring. The CDC found that 42 percent of chickenpox deaths from 1990 to 2001 occurred from March through May for people younger than 50. Only 7 percent of deaths in that age group occurred from August through October. The seasonal trend was weaker in older age groups.

Chickenpox Vaccination Guidelines

The chickenpox vaccine is recommended for all healthy children, teens, and adults who have not had chickenpox. Here’s a look at chickenpox vaccine recommendations:

--Babies can receive the vaccine along with some of the other routine immunizations that are given between 12 months and 18 months.

--Children aged 19 months through 12 years can receive the vaccine at any time.

--Healthy adolescents and young adults aged 13 and older who are susceptible to the infection should receive two doses of the vaccine four to eight weeks apart.

--Adults who have not had chickenpox should also receive two doses of vaccine.

The vaccine is especially recommended for the following adults:

--People who work in settings where they are likely to come in contact with people with chickenpox (for example, health care workers, child care workers, students in group living situations). Sometimes employers require proof of chickenpox immunity or vaccination.

--Nonpregnant women who can have children. Women who have not had chickenpox or the vaccine are at risk for complications of chickenpox during pregnancy.

--Family members of people with impaired immune systems. This protects them from having chickenpox and thus protects the family member with the impaired immune system.

--People who travel outside the United States. In some countries (especially tropical countries), chickenpox is a disease of adults.

Who Should Avoid the Vaccine?

Older children, teens, and adults can receive the vaccine at any time. Many states now require proof that children entering day care and school have either had chickenpox or have been vaccinated to prevent the virus.

A person who has been exposed to someone with chickenpox also can have the vaccine to prevent or decrease the severity of chickenpox. It is recommended that the vaccine be given within three days after exposure.

Chickenpox vaccine is not recommended for:

--Women who are pregnant or breastfeeding. Women need to wait three months after receiving the chickenpox vaccine before they become pregnant.

--Some people with impaired immune systems.

--People who are taking high doses of corticosteroids (search) by mouth. These medications weaken the immune system and may cause problems with this type of vaccination.

--People who are taking low doses of steroids or taking the medications by inhalation (such as people with asthma) may be able to take the chickenpox vaccine.

--People with serious long-term illnesses, such as children with leukemia.

--People who are allergic to the antibiotic neomycin (search). The chickenpox vaccine contains a small amount of neomycin.

--People who have recently received an injection of immune globulin (search). This medication increases the body's ability to fight infection. People need to wait for three to six months after receiving immune globulin before receiving the chickenpox vaccine.

By Miranda Hitti, reviewed by Brunilda Nazario, MD

SOURCES: Nguyen, H. The New England Journal of Medicine, Feb. 3, 2005; vol 352: pp 450-458. WebMD Medical Reference from Healthwise: “Chickenpox (Varicella) Overview.” WebMD Medical Reference from Healthwise: “Varicella-Zoster Vaccine for Chickenpox.”