Some 18 percent of American adults smoke, down from 42 percent in 1965. In places like New York City, which has used a combination of steep taxes on cigarettes and bans on smoking in most places to discourage smokers, the decline is even greater, down to 14 percent.

But health experts remain concerned because the rate of decline has stagnated over the last decade, and some 480,000 deaths each year are linked to smoking. From 1999 to 2003, for example, the smoking prevalence among high school girls dropped 37 percent, according to the Centers for Disease Control, but from 2003 to 2007, the decline was only 2.3 percent.

This month, a group of seven advocacy organizations including the American Heart Association and the Campaign for Tobacco-Free Kids called on governments to take steps to reduce smoking rates to less than 10 percent over the next decade and ensure no American is exposed to secondhand smoke within five years.

“We have seen the decrease in initiation of smoking plateau, particularly among some populations of young people, and we’ve been working very hard on those populations that have been stubbornly hard to reduce but we need to redouble our efforts,” said Risa Lavizzo-Mourey, the chief executive of the Robert Wood Johnson Foundation. “Decreasing the availability of tobacco products as CVS is doing is an important and bold step toward making it harder for people to get access to these harmful products.”

Coincidentally, the F.D.A. announced on Tuesday the start of a national education program aimed at preventing smoking among youth. The ads, which will be distributed across social media platforms, try to show teenagers the toll that smoking takes on the body in memorable ways, such as a young man who uses a pair of pliers to pull a stained tooth from his mouth to buy a pack of cigarettes.

A shortage of primary care doctors and expanding access to health care coverage under the Affordable Care Act is turning drugstore chains into big players in the nation’s health care system. Consumers routinely get flu shots in drugstores, for instance, and clinics staffed by nurse practitioners or physician assistants and offering basic care for common ailments like strep throat or pink eye are popping up everywhere from Walgreens to Walmart.

A report last year by Accenture predicted such so-called retail clinics were poised to grow at a rate of 25 to 30 percent over the next few years, which would swell the number to 2,800 in 2015, from 1,400 in 2012.