HARRISBURG, Pa. (AP) – Children in some parts of Pennsylvania should receive the first doses of free, voluntary swine flu vaccines as early as next week, officials said this week, as the federal government undertakes a massive immunization effort.

With a limited supply of the FluMist nasal-spray flu vaccine available first, Pennsylvania state Health Department officials decided that healthy children aged 5 to 9 in portions of the state where swine flu is most active should receive it.

That group made sense to focus on first because 5-year-olds to 24-year-olds are contracting the bulk of recent swine flu cases in Pennsylvania and they will need a follow-up dose three to four weeks later, officials said.

"Our figuring is let's get started in the group that's going to take longest to get protected," said Dr. Stephen Ostroff, Pennsylvania's acting physician general.

Swine flu cases are most prevalent in Pennsylvania's southeast, northcentral and southwest regions. Fourteen people in Pennsylvania have died as a result of swine flu, including a 45-year-old Butler County woman who died Sept. 10 and, authorities say, was otherwise healthy.

The nasal-spray vaccine is approved for use in healthy people ages 2 to 49. However, children under 5 in Pennsylvania seem to be less likely than older children to contract the virus, and children 10 and older need only one dose, not two, to be protected.

In the ensuing weeks, more vaccines approved for use in different types of people should become available, and the Health Department expects to post a list on its Web site of vaccine providers statewide.

By mid-January, Pennsylvania should receive enough doses to cover children and young adults from 6 months old to 24 years old; care workers who handle children younger than 6 months; pregnant women; health care workers; and people who are 64 and younger and have underlying medical conditions.

Once it arrives, the nasal-spray vaccine will be available through schools, doctors' offices and health clinics that preregistered with the state to administer it. Parents should call their child's school and doctor's office to find out if they are a provider of the vaccine, state Health Department officials said.

Wednesday was the first day that states could order the first doses of the nasal-spray vaccine through the federal government. Pennsylvania should get about 58,000 doses of the vaccine as part of the initial push to make doses available nationally, state Health Department press secretary Stacy Kriedeman said.

In the coming weeks, many more doses of the nasal-spray vaccine, as well as other types of vaccine, are expected to arrive in Pennsylvania.

"We anticipate that we could have about 2.5 million doses by the end of October," Kriedeman said.

In about a week, distributors that deliver the vaccines are expected to begin contacting doctors, schools and other providers in Pennsylvania shortly before the vaccines become available, they said.

The northcentral region includes: Bradford, Centre, Clinton, Columbia, Lycoming, Montour, Northumberland, Potter, Snyder, Sullivan, Tioga and Union counties.

The southwest region includes: Allegheny, Armstrong, Beaver, Butler, Cambria, Fayette, Greene, Indiana, Somerset, Washington and Westmoreland counties.

The southeast region includes: Berks, Bucks, Chester, Delaware, Lancaster, Montgomery, Philadelphia and Schuylkill.