The first 71,000 doses of H1N1 flu vaccine will be delivered to Chicago and the rest of Illinois state as early as Tuesday in the form of a nasal spray, Illinois State officials said Thursday.

Most of the initial doses, 16,000 for Chicago, 57,000 for the rest of the state, will go to health care workers and emergency personnel such as firefighters. They are among the groups on the federal government's high-priority recipient list because of their crucial occupations, particularly if the H1N1 flu becomes a widespread public threat.

The nasal vaccine has been deemed effective for the age group encompassing most of the health care and emergency workers, but is unsuitable for most people in other at-risk groups.

In all, the US federal government is sending out 600,000 doses of the nasal vaccine, the opening salvo in the nation's battle against the pandemic flu that first appeared in April and could strike as many as a third to half of the US population, according to government estimates.

The nasal mist vaccine would arrive first because it can be manufactured slightly more quickly than flu shots. The spray is made from a live but weakened version of the virus -- too weak to cause the flu itself, according to health experts.

The Illinois Department of Public Health oversees the orders and deliveries of all vaccines being distributed to 2,783 provider sites in the state outside of Chicago. The Chicago Department of Public Health oversees the vaccines delivered to 1,045 provider sites in Chicago.

(Xinhua News Agency October 2, 2009)