All children between ages 1 and 2 should be vaccinated against the hepatitis A virus, a national vaccine panel recommended Wednesday.

About 25 percent of hepatitis A cases occur in children, but many adults get the disease from infected youngsters, health officials said. The virus, which attacks the liver and can cause fever, diarrhea and jaundice, is sometimes caused by eating food contaminated with feces.

It is rarely fatal. But in 2003, nearly 600 people were sickened by hepatitis and three died in the nation's largest outbreak. The cause was blamed on contaminated onions served at a Pennsylvania restaurant.

The Advisory Committee on Immunization Practices, which helps set federal vaccination guidelines, voted unanimously to recommend that a two-dose vaccination be given young children. The panel's recommendations are routinely adopted by federal health officials and are influential to doctors.

Since 1999, the government has recommended Hepatitis A vaccinations for children in 17 states where rates of the disease were highest. But the success of those campaigns seems to have leveled off, and health officials fear rates may rebound.

Expanding the vaccination recommendation to all the states could prevent 100,000 cases and 20 deaths in the lifetimes of children vaccinated in one year. The direct costs of the vaccine program, currently at $22 million, would increase to $134 million.

Hepatitis A vaccines were first licensed in 1995, but it was only recently that the government approved their use in children as young as age 1.

Also on Wednesday, the panel unanimously recommended that pertussis vaccine be added to the tetanus-diphtheria booster shot for adults.

The action was an attempt to help prevent whooping cough deaths of infants who can catch it from adults who may not know they are infected.

Pertussis, or whooping cough, is a potentially fatal bacterial respiratory infection. Children are routinely vaccinated against it, starting at 2 months, although the protectiveness of the vaccine wanes after five years.

Pertussis is now considered rare. Reports have declined dramatically since the 1930s, and had leveled off before a rebound in this decade. About 26,000 cases were reported in 2004, up from fewer than 10,000 in 2000.

The number of asymptomatic adults carrying the infection is believed to be far greater than that. Most teens and adults sick with whooping cough suffer no more than a severe, multi-week cough. But they are an infection risk to infants who have not been fully vaccinated.

Each year, between 20 and 40 infants die from pertussis infection. Infant pertussis deaths are probably under-diagnosed, said officials with the federal Centers for Disease Control and Prevention.

In June, the government licensed a combined pertussis-tetanus-diphtheria shot for adults. The new vaccine costs about $33 per dose, or about twice the price of the current tetanus-diphtheria booster.

Also in June, the panel recommended pertussis-tetanus-diphtheria boosters for children ages 10-18. Wednesday's vote was the next step in expanding vaccination coverage.

Attending Wednesday's committee meeting was Pam Durkin, whose 5-week-old son, Colin, died from whooping cough in 2002. She doesn't know how he caught it. "It could have been anyone," she said, even her or her husband. They had not been vaccinated.

The vaccine panel encourages women of childbearing age, in particular, and people who expect to spend time around infants to get vaccinated.