Health 101: The Chickenpox Vaccine

The chickenpox vaccine protects against chickenpox, a virus that causes a rash of those telltale itchy spots. Highly contagious, chickenpox can spread through the air (from coughing, sneezing, and breathing) or from skin-to-skin contact with the rash. Before the vaccine was introduced in the U.S. in 1995, chickenpox was one of the most common childhood diseases -- there were about 4 million cases annually. Since the vaccine has become widely used in the U.S., chickenpox cases have decreased by up to 90 percent.

Though chickenpox is usually not dangerous, sometimes it can be. And even mild cases are pretty uncomfortable, if not outright painful, for your kid. (The virus causes kids to miss five to six days of school on average.) In serious instances, chickenpox spots can become infected, leading to scars, pneumonia, brain damage, and even death. About one in 500 kids who gets chickenpox is hospitalized.

The chickenpox vaccine isn't 100 percent effective (about 10 to 30 percent of people vaccinated may still come down with it), but it does make future cases significantly less serious. People who get chickenpox after being vaccinated typically have fewer spots and blisters, lower fever, and a faster recovery than those who are not vaccinated.

The vaccine also helps to protect your child from a similar disease called shingles. This virus strikes when the chickenpox virus, which typically remains dormant in the body forever after you've contracted it, reactivates -- causing another painful, blistery rash that can be especially serious in older adults. Research has shown that people who develop immunity to chickenpox naturally are much more likely to come down with shingles later in life than those who were vaccinated.