A: Jill, recommendations for vaccines change as new ones are developed to protect children against more of the serious diseases.

The hepatitis A vaccine was licensed in 1995. In 1999, the U.S. Centers for Disease Control recommended hepatitis A vaccine for children in 17 states with high rates of hepatitis A: California, Alaska, Arizona, Idaho, Nevada, New Mexico, Oklahoma, Oregon, South Dakota, Utah, Washington, Arkansas, Colorado, Missouri, Montana, Texas and Wyoming. It was also recommended for Alaskan Natives and Native Americans.

Hepatitis A is a viral infection of the liver that can cause fever, fatigue, loss of appetite, nausea, vomiting, abdominal pain and jaundice or yellowing of the eyes and skin. Children may have mild symptoms, but they often spread the infection to adult family members and childcare providers, who can get very sick for weeks. Hepatitis A is spread by contact with feces, when changing children's diapers or helping them with toileting, and when children and adults don't wash their hands well after going to the bathroom and before handling food. It is also commonly spread through food and water in developing countries that have poor sanitation.

Thankfully, the hepatitis A vaccine has been a tremendous success. A recent report showed that hepatitis A rates have dropped 76 percent since 1999, with an 89 percent drop in children ages 2 to 9.

The vaccine is recommended for children 2 and over and is given in two doses six to 18 months apart. Reactions are usually mild, e.g., swelling and soreness at the site of the shot. Severe reactions such as allergy are extremely rare.

All in all, it's a very good idea to get your baby immunized against hepatitis A. Also ask your doctor about immunizing your older children. For more information, visit the Centers for Disease Control website, www.cdc.gov.