This article — originally published on November 5, 2010 — was last updated on December 21, 2011. Scroll down for the latest updates.

In recent years, scientists and doctors have made huge strides in treating killer diseases, but the cure for the common cold has remained out of reach. Researchers occasionally report a "major breakthrough," but cold cures that appear promising "in a petri dish," says Liz Szabo in USA Today, "tend to fizzle out" when tested on humans. Now, a new study suggests that the best way to beat a cold has been staring at us for decades: Zinc. Should we get our hopes up this time? The truth is, says Tom Scocca at Slate, "medical science is still figuring out the basic facts about how and why people catch colds." Here's a look back at some so-called "cures" that didn't turn out so well:

An Austin osteopath and a researcher announce that they have found the cure. The secret, naturally, is "zinc," which "no one had ever tested clinically" as a cold cure before, says The Dallas Morning News. "Many patients who were treated early enough were free of symptoms within hours and on the road to recovery." One early sign this treatment was too good to be true? One of its founders called the discovery "serendipitous," saying, "I haven't done any original research."

"Despite pooh-poohs from some medical experts," says The Ottawa Citizen, a new invention called the Viralizer is "the closest thing to a cure for the common cold," according to its creator. The Viralizer, which "looks like a hair dryer," works by "directing a stream of warm air into the nostrils," thus killing cold-air-loving cold germs. Unsurprisingly, an area immunologist takes issue with the Viralizer's effectiveness, arguing that "if it really worked, we could all go into the steam room" to get rid of colds.

Two groups of researchers announced "a major step toward a way to prevent and possibly treat the common cold," says the Los Angeles Times. By identifying the "mechanism by which some cold viruses enter cells," scientists were able to "clone a 'receptor' molecule in nasal cells." This is, in the words of one leading scientist, "an absolute breakthrough" in the field of cold prevention.

"There is still no cure for the common cold," concedes The New York Times, but scientists are "closing in on the next best thing: Treatments that stop the sniffles, the cough, and the sore throat." By identifying "one of the first steps in the body's response to a cold infection," which is to release an "arcane substance" called interleukin-8, scientists hope to find a medicine that blocks the process — and they believe it might be a "prescription drug called Trental."

"Using an electronic device instead of medication," says the Warsaw, Ind., Times-Union, "Chinese doctors believe they have come up with a cure for the common cold." According to Xinhua, the Chinese news agency, "the heads of patients are placed into a 'thermoelectric field' that warms them slightly higher than normal body temperature." Such treatment conforms to Chinese medical tradition, which "holds that a cold always starts in the head."

"Next year," says CBS News, "a new wonder drug could take a bite out of the common cold." Pleconaril, which was "not so much discovered as designed" in a lab, "fits neatly into a groove on the surface" of a virus, "gumming up the machinery it needs to infect the body's cells." Could this be the sniffle solution we've all been waiting for? One doctor is unequivocal in his praise: "This IS the cure for the common cold."

"British volunteers are currently testing [a] drug which could clear up the sniffles within hours," says the London Daily Telegraph. The drug, which goes by the catchy moniker BTA798, "works by latching onto the cold-causing rhinovirus to prevent it breaking into the body's cells." Scientists have struggled with fighting numerous viruses at once, but BTA798 "has been built to defeat numerous strains of the virus." If trial results are successful, "the medication could be on the market within five years."

English researchers have made "a dramatic breakthrough that rewrites the medical textbooks," says Fox News, and "it could lead to a cure for the common cold." The key discovery is that "viruses can be destroyed by the immune system even after they have invaded human cells", whereas before, it had been though that "antibodies could only kill viruses outside the cell." But could this advancement finally lead to a cure? Many experts aren't buying it. "A cure for the common cold, this paper is not," says Ewen Callaway at Nature. "Not even close."

What's old is apparently new again in cold research, as the global Cochrane Collaboration finds promise in... zinc. An analysis of 15 previous clinical trials suggests that taking zinc lozenges or syrup within 24 hours of a cold's onset cuts the infection's life by at least a day and lessens symptoms, while taking zinc regularly may even prevent colds. The downside? "Toxicity concerns," says BBC News. Too much zinc might be dangerous, and "excessive amounts can cause nausea, vomiting, abdominal pain, and diarrhea." Zinc supplements help, if you "can stand them," says USA Today. In the end we're still stuck with the "dirty little secrets about the common cold: Nothing cures it." But can new advances challenge conventional wisdom? "Just as antibiotics kill many different types of bacteria," a new broad-based "wonder drug" developed by MIT scientists, called Draco, has been tested successfully against 15 different viruses, including H1N1, swine flu, polio, and the common cold — at least in mice and human tissue samples, says BBC News. Critics are naturally skeptical, and it could take "several years" before Draco can be tested on humans. An "intriguing result," says io9, but "there's a long road ahead."

Editor's note: This article originally mischaracterized the Draco research, which has indeed been peer-reviewed. We regret the error.