JUDY WOODRUFF:

Now to our series on the hunt for new antibiotics, as superbugs and bacteria are building more resistance to the current line of drugs.

It is a joint project from our correspondents Paul Solman and Miles O'Brien.

Last night, Paul looked at why the market for developing new drugs is simply no longer working. But, as one expert warned, antibiotics are a class of drugs that could be lost for treatment if there's no new investment.

As part of his series Making Sense, Paul looks at some new options for solving that problem.