NEW YORK — With the end of summer in sight, the onset of flu season is just around the corner. Flu season can begin as early as October and continue through mid-May, but several drug chains have already unveiled flu vaccination programs to help consumers fend off the disease.

The three largest chains, Walgreen Co., CVS/pharmacy and Rite Aid Corp., have all launched programs that offer maximum convenience.

CVS/pharmacy and MinuteClinic are offering flu shots on a walk-in basis everyday at all of their locations nationwide. The company noted that its drug stores and clinics are among the most convenient places to get a flu shot. There are 7,300-plus CVS/pharmacy locations and nearly 600 MinuteClinics, which provide flu shots without an appointment daily, including evenings and weekends.

In addition, CVS has more than 20,000 immunizing health care professionals available at CVS/pharmacy and MinuteClinic to provide flu vaccines.

"Influenza causes between 3,600 to 49,000 deaths and 200,000 hospitalizations in the U.S. annually. Receiving a flu shot can reduce the chance of becoming infected by up to 70%," stated Papatya Tankut, vice president of pharmacy professional services for CVS/pharmacy.

People receiving a flu vaccination at CVS/pharmacy or MinuteClinic will get value as well, according to CVS. This flu season, customers will receive a 20%-off CVS/pharmacy shopping pass when they get a flu shot at CVS or MinuteClinic. The shopping pass can be used with CVS/pharmacy’s ExtraCare card to save 20% on nonpharmacy purchases up to $100. A seasonal flu shot at CVS/pharmacy or MinuteClinic costs $31.99.

CVS also is offering a flu shot voucher program this month as part of CVS/pharmacy’s Project Health free screening events in major markets across the country.

Rite Aid, meanwhile, is offering shots by a certified immunizing pharmacist at any of its 4,600-plus pharmacies. The shots cost $29.99 each and are covered by many insurance plans, including Medicare Part B.

Rite Aid customers who get flu shots also receive a free coupon booklet that offers more than $100 in savings. Members of Rite Aid’s customer loyalty program, wellness+, earn 25 points when they receive a flu shot, with some restrictions in the states of New York and New Jersey.

For its part, Walgreens is making flu shots available without appointment daily at all of its nearly 8,000 stores, including Duane Reade pharmacies in New York and the 360-plus Take Care Clinics in select Walgreens locations. The shots are available during all pharmacy and clinic hours, including nights at 24-hour locations.

According to the company, the off-hours availability has proven to be a valued convenience, as 32% of the more than 6.3 million vaccinations administered during the 2010-2011 flu season were done outside of normal business hours. However, for those customers who prefer them, appointments are available and can be scheduled online.

New for this season, Walgreens is also offering a free, comprehensive immunization assessment with every flu shot, which can help patients determine whether they need other immunizations.

Boulder, Colo.-based Pharmaca Integrative Pharmacy, meanwhile, announced that it’s offering an expanded selection of immunizations on a walk-in basis at all locations.