Napa County’s first shipment of swine flu vaccine arrived Tuesday, triggering local public health officials’ plans to distribute the initial batch to people deemed most vulnerable to the virus.

Although enough swine flu, or H1N1, vaccine will eventually become available in Napa County to inoculate everyone seeking protection from the virus, the initial shipment is reserved for people the Centers for Disease Control and Prevention deems high-risk, according to the Napa County Public Health Department.

That group includes pregnant women, generally everyone between six months and 24 years old, caregivers for infants, health care workers and people with specified health conditions.

“Like communities all over the country, our initial shipment of the H1N1 vaccine is small and comes to us in the form of the nasal spray,” Napa County Public Health Officer Dr. Karen Smith said. “In accordance with CDC and state recommendations, we’ll ensure that those first doses are administered to otherwise healthy children with no underlying medical conditions. We’ve been told to expect that by November, we’ll have enough vaccine for anyone who would like it.”

For now, Smith said, people in priority groups should talk with their doctors about which form of the vaccine would be best for them. The lion’s share of vaccine received in Napa County will become available through pediatricians, other private practice doctors and Kaiser physicians, according to the county.

Public Health officials expect to offer the vaccination to high-risk people in October at select clinics. Larger-scale public vaccination opportunities will follow the expected arrival of more shipments in late October and early November, according to the county.

In accordance with CDC recommendations, children younger than 10 years old will need two doses of the nasal spray, but other people will require just one, Napa County spokeswoman Elizabeth Emmett said.

Emmett said she is unaware of any side effects caused by the nasal spray, but said the injected form of the vaccine can cause soreness or swelling at the injection site.

Although Guillain-Barré syndrome — a paralyzing neurological illness — was suspected in the 1970s to have a connection with swine flu vaccine, all but one of several studies over almost four decades revealed no connection, according to the CDC.

Conclusions from one study showing a link that one out of every million vaccinated people “may be at risk of GBS associated with the vaccine,” according to the organization’s Web site. The CDC also indicates that the illness’ trigger in the vast majority of cases is instead a bacterial infection unrelated to vaccinations.

“They don’t expect it to be a risk at all, but just like they do with any vaccine, they’ll be keeping track of any adverse reactions anyone has and they’ll be reporting it nationwide,” Emmett said.

More information about the H1N1 vaccine is available at www.co.napa.ca.us or by calling 253-4270.