$hot in the arm; Drugstores dive deeper into flu vaccines.

• Jurisdiction: United States
• Author: Murphy, Tom
• Date: 19 September 2014

Byline: Tom Murphy

Walgreen provided enough flu shots last season to protect a population roughly twice the size of Los Angeles.

CVS doled out more than 5 million, or double its total from a few years ago. And Wal-Mart, the world's largest retailer, offers flu shots at more than 4,200 of its U.S. stores that have pharmacies.

The nation's biggest drugstores and other retailers are grabbing larger chunks of the immunization market, giving customers more convenient options outside the doctor's office to protect themselves against the flu, pneumonia and other illnesses. In fact, nearly half of all flu vaccines provided to adults are now administered in nonmedical settings like drugstores or worksite clinics.

But this push by retailers muscles into an area of health care that was once largely the domain of the family doctor. And that stirs some concern from doctors who want to stay tuned into the health of their patients and keep...