Missouri is set to receive an additional 365,000 H1N1 flu vaccine doses over the next two weeks.

On Tuesday, approximately 17,000 doses of aerosol mist vaccine arrived in Missouri and were distributed to doctors' offices, clinics and local health departments.

The next shipments will include up to 250,000 doses of the injectable form of the vaccine, which will be safe for pregnant women and children younger than 2 years old. Both groups are considered high risk.

Margaret Donnelly, director of the Missouri Department of Health and Senior Services, said the first week's shipment is relatively small because health officials were trying to make the vaccine available quickly.

Officials had to choose between waiting until large quantities were ready to ship or distributing smaller quantities of the vaccine as soon as they came off the production line.

"The decision was made to ship vaccine immediately so we could start protecting people against this disease as soon as possible," Donnelly said. "With the shipments expected in the next two weeks, we believe we will meet our goal of having significant amounts of vaccine available throughout the state by mid-October."

This season there is a seasonal flu vaccine to protect against seasonal flu viruses and a 2009 H1N1 vaccine to protect against the 2009 H1N1 influenza virus, according to the Centers for Disease Control and Prevention (CDC).

The CDC added that a 2009 H1N1 "flu shot" is an inactivated vaccine (containing the killed virus) that is given with a needle, usually in the arm. The indications for who can get the 2009 H1N1 flu shot are the same as for seasonal flu shots. The flu shot is approved for use in people 6 months of age and older, including health people, people with chronic medical conditions and pregnant women. The same manufacturers who produce seasonal flu shots are producing the 2009 H1N1 flu shots for use in the United States this season.

Also, the 2009 H1N1 vaccine can be in the form of nasal spray which is a vaccine made with live, weakened viruses that do not cause the flu. The indications for those who can get the 2009 H1N1 nasal spray vaccine are the same as for seasonal nasal spray vaccine. This is approved for use in healthy people 2 years to 49 years of age who are not pregnant. The nasal spray vaccine for use in the United States is being made by MedImmune, the same company that makes the seasonal nasal spray vaccine called "FluMist."