In its new advertising campaign, Subway is looking back to the sandwich chain's founding in 1965, according to a report by Ad Age. The first round of ads, which use the tagline "Founded on Fresh," will run for about two months.

The campaign by new agency BBDO tells the story of how Subway founders Fred DeLuca and Peter Buck started the chain with a simple idea of creating fresh sandwiches at a "time when artificial foods and gimmicks were all the rage." The campaign, which launched Dec. 27, marks the beginning of a significant strategy shift for Subway, which is seeking to recover from sluggish sales trends and PR woes related to the downfall of former pitchman Jared Fogle.

The new approach will include fewer celebrities and less talk about discounts. For instance, the oft-used "Five Dollar Footlong" jingle will be eliminated. Also, the chain's "Famous Fans" line-up of star endorsers, which in recent years has included celebs like Olympian Michael Phelps, has been retired.

"Fresh as a subject has really changed from when we introduced it 15 years ago when it was about making the sandwiches fresh and having fresh produce," said Chief Advertising Officer Chris Carroll. Now, he said, fresh is more about what goes into the ingredients, including concerns about antibiotic use. "It's not just an advertising change to the brand. This is an entire company effort, from products to the way we operate the restaurants."

As part of that effort, Subway this spring is planning to introduce a rotisserie chicken sandwich that is "completely antibiotic-free," Carroll said.