After nearly a year of intense pressure from advocacy groups, Kentucky Fried Chicken has announced that it will phase out serving chicken raised on medically important antibiotics by the end 2018. These drugs are those in classes of antibiotics that are not typically used in humans, such as ionophores.

The goal of such a pledge is to lower the chances of creating antibiotic-resistant microbes on farms that could spill over to people and cause difficult-to-treat infections. In making the announcement, KFC joins many of its peers and fierce competitors. With KFC, 11 of the 15 top restaurant chains in the country have now made some form of commitment to be better stewards of antibiotics. Those other top, drug-conscious brands include McDonald's, Subway, Chick-Fil-A, Chipotle, Wendy’s, Panera Bread, and Taco Bell.

In a press statement, Kevin Hochman, president and chief concept officer for KFC US said:

We're constantly working to meet the changing preferences of our customers, while ensuring we deliver on the value they expect from KFC. Offering chicken raised without medically important antibiotics is the next step in that journey. Making this change was complex and took a lot of planning. It required close collaboration with more than 2,000 farms, most of them family-owned and managed, in more than a dozen U.S. states where they raise our chickens.

KFC’s decision comes after nearly a year of intense pressure from the Natural Resources Defense Council (NRDC) and partnering advocacy groups, including the Center for Science in the Public Interest, Consumers International, Food Animals Concern Trust, and US Public Interest Research Group.

In May of last year, the groups rolled out a full-blown campaign to sway KFC, involving thousands of petitions, mobile billboards, and collecting data on the restaurant chain's practices. The NRDC also unveiled a mascot for the campaign: a chicken covered with pills, called Auntie Biotic. The NRDC had a series of online videos showing Auntie Biotic outside of KFC restaurants, interacting with customers.

In a statement, the NRDC applauded the restaurant's announcement. The group’s food policy advocate, Lena Brook, said:

KFC’s new policy will be a game-changer for the fast food industry and public health. While federal antibiotics policy stagnates, the market is responding to consumer demand for better meat. This commitment from the nation’s most iconic fast food chicken chain will have a major impact on the way the birds are raised in the U.S. and in the fight against the growing epidemic of drug-resistant infections.

The NRDC is hopeful that the move will come with side benefits. Because KFC often only buys portions of chicken from a flock—due to internal standards—the advocacy group speculates that KFC’s new standards will be applied to chicken going to other buyers.

Currently, more than 70 percent of medically important antibiotics are sold for use on farms. Every year in the US, at least two million people are infected with antibiotic-resistant bacteria, resulting in at least 23,000 deaths.

Last September, the NRDC and partners released a report that graded various restaurants on their policies and practices relating to antibiotic use. The groups gave KFC an F.

Editor's Note: This post has been updated for clarity.