Medical experts advise that people should get a vaccine for the bird flu when it becomes commercially available. One doctor said the most at-risk patients should be first.

An infectious disease expert says the relatively mild cases of avian influenza detected so far among dairy workers don’t warrant making a vaccine available to them, even as they work to contain and prevent spread of the contagious virus among herds.

Experts say no bird flu vaccine is needed for humans yet, as mild cases among dairy workers don't warrant it. The current H5N1 strain shows low human transmission risk and responds well to antivirals.

We last spoke in April, after a dairy worker became infected with bird flu. At the time, you described your level of concern about bird flu as “medium.” How would you describe your level of worry now?

As bird flu continues to ravage farms across the nation, fears have grown of bird flu starting a massive epidemic in humans.