Two months after the long-awaited chickenpox vaccine began arriving in doctors' offices, many parents and pediatricians are weighing it against a time-tested alternative -- letting children get sick.
The vaccine appears likely to win general acceptance. After all, tests show that it should spare most families the ordeal of spending miserable days at home nursing itchy, irritating blisters.
But at the same time, some pediatricians are soft-peddling the vaccine -- suggesting that the only sure way to give children lifelong protection against the viral disease is to let them get the illness, preferably before adolescence.
"The majority of highly knowledgeable pediatricians have not been actively pushing the vaccine," said Dr. Daniel Levy, an Owings Mills pediatrician who is regional spokesman for the American Academy of Pediatrics.
"Right now, parents are being given the option, and I would say that 50 percent of the parents opt for the vaccine and 50 percent don't."
In March, Merck & Co. won federal approval to market the vaccine to the general public. It began delivering the product, called Varivax, two months later.
The American Academy of Pediatrics endorsed it, recommending universal use in early childhood and the immunization of older children who have yet to get the disease.
Some physicians say they are concerned by results of a 10-year study that showed the vaccine prevented the disease in only 70 percent of vaccinated children.
They worry that the vaccine's potency will wane over a person's life, leaving the patient unprotected in adolescence or adulthood when the disease is most serious.
In contrast, one bout with the natural illness protects a person for life. Children usually recover within a week to 10 days.
But Dr. Neal Halsey, chairman of the Academy's committee on infectious disease, said the study has been widely misinterpreted. He said the vaccine prevented serious disease in 95 percent of the vaccinated individuals.
Among the 30 percent who developed chickenpox, most got an extremely mild illness characterized by an average of 10 sores resembling small mosquito bites.
"As with all other vaccines, it's not perfect, but the vaccine clearly provides a number of benefits to children and their families," said Dr. Halsey, a pediatrician who runs the division of disease control at the Johns Hopkins School of Hygiene and Public Health. "It's far safer and better to be immunized than to allow children to have the natural disease."
While conceding that the natural disease is usually mild, he said it sometimes spurs more serious illnesses such as pneumonia and encephalitis.
The open pox also can serve as conduits for dangerous bacterial infections that can invade skin and muscle -- and prove fatal if not caught early.
"The skin infections are not uncommon," Dr. Halsey said. "We have several hospitalizations every year here at Hopkins."
For most families, he said, the chief benefit is economic.
"There should be $5 saved for every dollar spent, largely in the realm of parents not having workdays lost, staying home with kids," he said. The vaccine costs patients $50 to $60 and is covered by most insurance plans.
Government clinics that supply free immunizations to uninsured families are not offering the new vaccine but are expected to do so by January.
They are awaiting a recommendation from the Advisory Committee on Immunization Practices, which is expected to endorse the vaccine in several weeks.
Dr. Virginia Keane, who runs the University of Maryland's pediatric clinic, said the economic factor is a significant one for low-income families. She said mothers can ill-afford to miss work chickenpox races through their households.
She said she has seen children miss days and even weeks of school after they were ready to return. Schools often require a doctor's note certifying that a child is no longer contagious. Some mothers, she said, have trouble getting the notes because they are home caring for their other sick youngsters.
"You've got to wonder why a kid should be put through being sick if they don't have to," she said. If future tests show waning effectiveness, she said, children will begin to receive a booster shot several years after their initial immunization.
Nonetheless, many doctors feel that too little is known about the vaccine's long-term effectiveness.
"In the younger children, we're not recommending it," said Dr. Frances Gmur, a pediatrician in a group practice in Lutherville. "We really prefer that they get the disease. Our feeling is that they are going to get better immunity, and it's not such a terrible disease for children to get as compared to an adult."
Dr. Gmur said she is recommending the vaccine for children over 13 who have not had the disease.
Deborah Skupien, the mother of a 3-year-old girl, said she felt comfortable passing up the vaccine on the advice of Dr. Alan M. Davick, one of Dr. Gmur's colleagues.
"You're not sure what insurance you are buying," Ms. Skupien said. "I was concerned about the lack of immunity over time and that I'd have a false sense of security."
The American Academy of Pediatrics recommended that the chickenpox vaccine be given to these groups:
* Children 12 months to 18 months of age, a single dose. It can be given at the same time as the child's first measles-mumps-rubella shot.
* Children under 13 who have not been immunized, also a single dose. It can be given at their earlier convenience.
* Healthy adolescents past their 13th birthday who have not been immunized and have never had chickenpox. Two doses four weeks to eight weeks apart.
* The vaccine should not be given to people with immune disorders such as AIDS and to cancer patients receiving immunosuppressant therapy. Some cancer patients are getting the vaccine in a clinical trial.