When it comes to getting a flu shot, Louise Lorenzo likes the convenience of going to her neighborhood drugstore. She doesn't need to make an appointment or have to pay for a visit to the doctor.So when the 86-year-old saw a sign advertising flu shots at her Walgreens in Tampa, she didn't hesitate to roll up her sleeve."I came here to pick up my husband's prescription, and I want to get my flu shot," she said while waiting for a pharmacist on Wednesday. "Let me get it out of the way."Lorenzo joined a growing number of adults getting their flu shot at drugstores and other retail outlets. While the majority still get vaccinated at their doctor's office, about 20 percent of adults received shots at a retail pharmacy last year, up from 12 percent the previous year, according to the Centers for Disease Control and Prevention. That's more than workplaces or health clinics.And now, for the first time, older Floridians can get pneumonia and shingles vaccinations at their local pharmacy under the Vaccine Access Act passed this year by the state Legislature.The CDC recommends people ages 6 months and older get influenza shots as soon as the vaccines become available in their community, usually in August. The vaccines change from year to year to protect against different flu strains and take about two weeks to become effective.Flu season runs from October through May, with October and November being the busiest months for vaccinations. The CDC doesn't know exactly how many Americans die from seasonal flu each year. It estimates that the annual toll between 1976 and 2006 was anywhere from 3,000 to 49,000. Those numbers would include cases in which the flu was likely a contributor to the death, but not necessarily the primary cause.Influenza hits the elderly the hardest with about 90 percent of deaths occurring in people ages 65 and older. Last year's flu season was mild, but health officials say that's no guarantee this year will be the same.Drugstores and supermarkets stepped up their marketing efforts of flu shots in 2009 during the outbreak of H1N1, also known as swine flu. Facing a shortage of the vaccine, many patients went to retail stores when their doctor's office ran out."We recognized a need for greater immunization resources in this country and the role of the health care pharmacist," said Jim Cohn, a spokesman for Walgreens, based in Deerfield, Ill.Stores such as Walgreens and CVS offer round-the-clock flu vaccinations every day at every store as soon as the serum becomes available. The shots are covered by many insurance plans and Medicare Part B and usually require no co-pay. Otherwise, the price is $31.99 at Walgreens and CVS, $30 at Publix and $28 at Target, to name a few stores.Last year, Walgreens administered 5.5 million flu shots, making it the largest provider of the shots outside the federal government. CVS did 3.5 million — a large number considering it has only offered flu vaccinations at every store since 2010, said chain spokesman Mike DeAngelis. Before that, CVS hosted shot clinics at select locations.David Holland, the pharmacy manager at the Walgreens at Swann Avenue and Henderson Boulevard in Tampa, expects his store to administer 1,500 flu shots this season. So far, he's averaging about 60 people a week and just recently started seeing a rise in demand. On Monday, the store vaccinated 16 customers before noon."They come here for our service and their confidence in our pharmacy," he said. "For the most part, there's never a long wait."The pharmacy accounts for about 65 percent of the store's sales, about standard for the industry, he said.Vaccinations have become big business for retail outlets, which compete vigorously for a larger share of the market but don't divulge revenue generated by shots. CVS is offering a 20 percent shopping pass for anyone who gets a flu shot. Walgreens is giving 1,500 points toward its Balance Rewards program for money off future purchases.Shots help stores build customer loyalty and promote their other wellness programs, such as cholesterol and blood pressure screenings. They also get shoppers through the door to buy milk, birthday cards and other front-of-the-store merchandise."People who come in for a flu shot or to pick up a prescription, the expectation is that they would do some shopping as well," Cohn said.Walgreens has not detailed how much additional business is generated from shots but considers vaccinations a key part of the company's strategy to "help people live well" and become an integral part of their health care team, he said.Last year, about 128 million Americans, or 42 percent of the population, received a flu shot. That was about the same as the previous year but well below the target rates of 80 percent for people ages 6 months to 65 years and 90 percent for those over 65.Retail pharmacies typically have age requirements for administering shots: 18 years old for influenza, 60 for shingles and 65 for pneumonia. Depending on the store, customers who want shingles or pneumonia shots may need prescriptions.Many drugstores offer the high-dose vaccine for people over 65, provided they haven't had a strong reaction to a vaccine in the past. Only stores that have medical clinics on site, such as CVS's Minute Clinics and Walgreens' Take Care Clinics, offer flu shots for children, often starting at 18 months old. Depending on availability, some stores have intradermal thin needles or nasal spray flu vaccines.The CDC recommends one-time shingles shots for seniors ages 60 and up, even if they already had an outbreak of the painful skin rash. The vaccine became available in 2006 and must be stored frozen to maintain its potency. Those factors make it expensive — about $220 per shot — although many insurance plans cover some or all of the cost.Retail outlets have been advertising the shingles shots to seniors as part of their overall vaccination schedule. Although demand is far less than for flu shots, response has been strong as the baby boomer population explodes and more seniors become aware of it, said Cohn of Walgreens.While retail vaccination programs have mostly been well-received, some health officials caution that they shouldn't replace regular visits to primary-care physicians. To ensure proper vaccinations, customers can ask their pharmacy to check with their doctor about getting a shot or forward the shot record to their physician's office.The CDC has taken no position on retail outlets administering flu shots but highly encourages people to get vaccinated."It's the single most important thing people can do to protect against the flu," said CDC spokesman Tom Skinner. "If it's convenient for them to get their vaccine while they are out shopping, then that's good."