TRENTON - New Jersey moved toward becoming the first state to require flu shots for preschoolers yesterday after a health advisory board backed new vaccine mandates over the opposition of worried parents.

The Public Health Council voted to require New Jersey children attending preschool or licensed day care to get annual flu shots, and to get three additional vaccines for youngsters starting Sept. 1, 2008.

No other state requires preschool, day-care or older students to get flu shots, according to the American Academy of Pediatrics.

State health officials want preschoolers to get the flu shots because their immune systems are not as developed as those of older children and because they are more likely to transmit the flu virus.

The state's health commissioner, Fred M. Jacobs, has until next Tuesday to sign off on the mandates, although they have already been approved by Gov. Corzine. Health Department spokesman Tom Slater said Jacobs was expected to approve them.

Besides the flu shots, New Jersey also will require preschoolers to get a pneumococcal vaccine, and sixth-graders to get a whooping cough booster shot and a meningitis shot.

"Implementation of these rules will save lives and prevent disease and suffering in children, their families and the community," deputy health commissioner. Eddy Bresnitz told the council yesterday.

The council voted in favor of the requirements 5-2 with 1 abstention, with member Dennis San Filippo saying he would like to see studies done on whether it's safe for young children to get so many different vaccines.

All four vaccines are recommended by the federal Centers for Disease Control and Prevention, the American Academy of Pediatrics and other medical groups.

Parents concerned about possible dangers of the new vaccines and government intrusion into family medical decisions have been trying to block the mandates.

They note that flu vaccines contain trace amounts of mercury, a toxic heavy metal, and that mercury-free shots can be difficult to obtain.

According to the Centers for Disease Control and Prevention and other scientific groups, there's no convincing evidence the trace amounts of mercury in flu shots cause harm.

Following the vote, concerned parents said they will keep urging support for a bill that would give parents the right to invoke a "philosophical objection" to vaccine mandates.