JUDY WOODRUFF:

Now: Who should pay when drugs are very effective, but extremely expensive?

That's an important question for the U.S. health care system as new treatments come along, and it's a matter of real concern over a new drug that has a 90 percent to 100 percent chance of curing the hepatitis C virus. Its manufacturer announced record sales yesterday of more than $2 billion in just the first quarter of the year.

Profits, coverage and costs are all at issue, as Hari Sreenivasan reports.