The Salt Lake Valley Health Department is starting to call parents to remind them to get their young children a second dose of the H1N1 vaccine.

Children under age 10 need two doses to become fully protected against the virus.

But of the 23,400 doses given to children at the Health Department's public clinics, just 29 percent have received a second dose. That leaves about 16,600 children needing a booster. The doses must be given at least a month apart. Even if parents have waited longer, the second dose will still provide protection.

Health officials say parents have become complacent, since the flu season appears to be over. Officials don't know, however, if a third wave of H1N1 cases will hit in the spring.

While there have been no new local hospitalizations or deaths attributed to H1N1, Utah is one of the few states where the flu continues to spread.

The Health Department's four clinics are accepting walk-in appointments for the free vaccine Monday through Friday from 8:30 a.m. to 4:30 p.m. For clinic locations, go to slvhealth.org.