So far, the news about swine flu is better than expected. The pandemic may have reached its peak and is heading downward in all regions of the country; weekly deaths from swine flu have started to decline; the virus remains relatively mild; there seem to be few claims of serious side effects from the vaccine; and despite widespread complaints about shortages, vaccine supplies are steadily building up.

By mid-October, the latest estimates available, the swine flu had infected some 22 million Americans, sent roughly 98,000 to the hospital and killed roughly 3,900. Those numbers may sound high, but they are not apt to reach the levels of harm caused by a normal flu season. One big unknown is whether we will see a normal flu epidemic on top of the swine flu outbreaks or whether the swine flu will crowd out the seasonal flu, which has barely been detected here.

Supplies of seasonal flu vaccine have also been running short. The five companies licensed to make flu shots for this country had expected to make more than 118 million doses, but manufacturing glitches and the need to convert production to swine flu vaccine cut the supply of seasonal flu vaccine to 114 million doses. Even 118 million would not have been enough to meet demand that was revved up this year by all the publicity surrounding the new swine flu. (The vaccines are not interchangeable.)

Even as the swine flu seemed to be waning last week, health officials voiced concerns that Thanksgiving travels and get-togethers could lead to new outbreaks. And there were a few hints of troubling developments.