What are the benefits of the chicken pox vaccine?

It may seem unnecessary, because childhood chicken pox (also known as varicella) is usually a relatively mild illness. And some parents think it's better to let their kids be exposed to chicken pox so they'll have the illness (and the resulting immunity) naturally.

But most experts now recommend the chicken pox vaccine, and many schools and daycare centers require it. Here's why:

1) Chicken pox is no party. If your child gets it, he's likely to develop a rash of itchy, painful blisters accompanied by fever and fatigue. If the blisters get infected, he may need antibiotics. They may also leave permanent scars, possibly on his face. If he's going to daycare or school when he gets chicken pox, he'll have to stay home for eight or nine days.

2) Chicken pox can be serious and even deadly. Before the vaccine came along, an average of 10,600 hospitalizations and 100 to 150 deaths caused by chicken pox occurred annually in the United States. Most of the severe complications and deaths occurred in previously healthy people.

3) The vaccine will protect your child from the worst of this illness. While the vaccine isn't 100 percent effective (about 15 percent of vaccinated children still get chicken pox), vaccinated children who come down with it will have only very mild symptoms. That usually means fewer than 50 blisters, no fever, and less sick time.

4) The vaccine can help protect your child against a related disease called shingles. About 10 percent of adults who have chicken pox earlier in life get this rash of extremely painful and disfiguring blisters that can be inches across.

Shingles appears when the chicken pox virus, which lives forever in the central nervous system, "reawakens" and becomes active again. People who have been vaccinated against chicken pox may still get shingles but will have a much less severe case than those who had the disease itself.

For all these reasons, both the American Academy of Pediatrics (AAP) and the Centers for Disease Control and Prevention (CDC) have put the chicken pox vaccine on the schedule of recommended immunizations.