DEERFIELD, Ill. — Walgreen Co. and the Health and Human Services Department (HHS) have joined forces to provide flu vaccinations to hundreds of thousands of people who may not otherwise be able to afford them.

In a joint press conference last month officials from the drug chain, HHS and the Centers for Disease Control and Prevention (CDC) unveiled a program that has seen Walgreens start to provide more than $10 million worth of vouchers for free flu shots in 15 markets with high concentrations of uninsured and underserved people.

“This is an important time for flu prevention,” Walgreens president of pharmacy services Kermit Crawford said during the briefing on the program. “While the flu season is always unpredictable, it traditionally peaks in January and February.”

In mid-December Walgreens began offering the flu shot vouchers in eight markets — Atlanta; Chicago; Houston; Kansas City; Newark, N.J.; Oakland, Calif.; Philadelphia; and the borough of the Bronx in New York City.

Crawford said that at some point the company would also begin providing vouchers in Fort Lauderdale, Miami and Palm Beach, Fla., as well as in Seattle; Waco, Texas; Washington, D.C.; and parts of New Hampshire. The $10 million is expected to cover 350,000 vaccinations.

HHS and CDC officials say targeting residents of these areas, many of whom are Hispanic or African-Americans who are more likely to get flu-related complications, is particularly important in the effort to minimize the impact of a flu outbreak.

“Over the years too many Americans have gone without a flu shot because they can’t afford it,” HHS Secretary Kathleen Sebelius said. “That should not be the case.”

Health officials say that by the end of November about one-third of Americans had gotten a flu shot. Of the remaining two-thirds, a high percentage fall into these high-risk groups.

“We need to reach more patients in minority communities where vaccination rates have traditionally been much lower,” assistant HHS secretary Dr. Howard Koh said. “Walgreens’ program is a commitment to public health that will go a long way toward supporting the efforts of public health officials.”