A Darien physician says he hasn't been able to purchase any seasonal flu vaccines for his patients because pharmacy chains are buying up all the available doses.

According to Dr. Michael Schwartz, distributors of the flu vaccine prefer to sell millions of doses to pharmacies like Walgreens and CVS that buy wholesale, instead of a few hundred to doctors with private practices.

"Without adequate supply, we're putting some of our patients at risk," Schwartz says.

Schwartz says he has to wait until mid-October to find out if he can purchase any doses of the vaccine.