How Come We Can't Cure The Cold?

By this point, nobody needs a refresher course on the symptoms of the common cold. With just one more month left in peak cold season, most folks have already suffered their share of scratchy throats, runny noses, raucous sneezes and nagging headaches. If only the changing weather meant you were out of harm's way. Alas, colds are caused by hundreds of different viruses from several major viral families. Spring turns out to be prime time--along with summer and fall--for the so-called rhinoviruses, culprits in as many as 35% of all colds. There's just no time of year when some type of cold virus can't get you.

Besides making sufferers miserable, colds are also more of a drain on the economy than most of us realize. A study from the University of Michigan, published in last week's Archives of Internal Medicine, estimates that colds cost the U.S. $40 billion a year--more than the tally for osteoporosis or congestive heart failure. "If anything, that number is probably on the low side," says Dr. Mark Fendrick, who led the study. He notes that earlier estimates, which had put the cold burden at $5 billion to $10 billion, did not account for, among other things, the fact that parents often stay home from work to care for their ailing children.

It wasn't supposed to be this way. When researchers published their first highly detailed analysis of the structure of a human rhinovirus back in 1985, it was easy to imagine that a cure for the common cold might soon be available. After all, once scientists discovered which molecular footholds rhinoviruses use to latch onto and infect human cells, it should not have been that hard to develop a drug that would block the linkage and cure a cold before it got started. Or so the thinking went. Unfortunately, the logistics, from both a biological and a business point of view, turned out to be a lot more complicated than anyone expected. The crash of the biotech sector, in which some of the more interesting anticold research has taken place, certainly didn't help.

First, the biology. Doctors pretty quickly gave up on the idea of developing one vaccine to prevent all common colds. There are just too many kinds of cold viruses to make that a practical approach, which leaves us treating our colds after they have already started. But here's the rub. Researchers know that most of the symptoms we associate with getting a cold--the runny nose, the congested sinuses--are caused not by the cold virus but by the body's attempts to clear the virus. It turns out that our body's immune system automatically tries several strategies to counter the virus--some more effective than others. Most of the suffering can be traced back to the so-called inflammatory response, which actually does nothing to beat the cold virus.