If ever there was a Holy Grail, it’s finding a cure for the common cold. Few maladies have been studied more but have revealed less. Colds are seasonal: in most parts of the world, the season begins in the fall, trudges through winter and ends by mid-spring. Oddly, colds almost disappear in summer, whether it’s summer in Alert, Nunavut or in Adelaide, Australia, one of the world’s hottest cities. Canadian adults endure an average of two to four colds a year, while children get six to eight. Neither the shelves of medicines in pharmacies nor the many herbal cures (echinacea, zinc, goldenseal) nor the dozens of home remedies (chicken soup, garlic cloves, honey-and-vinegar syrup) do much more than provide a little relief to the sufferer.
So it’s hard to imagine voluntarily catching a cold. Yet that’s what Jennifer Kim, a stay-at-home mom in Calgary, did last spring at the “Cold Lab” – correctly called the Respiratory Clinical Trials Centre – located in the Tamaratt Experimental Respiratory Suite at the University of Calgary’s Snyder Institute for Chronic Diseases. It’s the only Canadian facility approved by Health Canada to infect people with a cold virus; specifically, human rhinovirus 39, one of more than 200 or more viruses causing the common cold.
At U of Calgary’s clinical trials centre, a team of respirologists and clinical coordinators oversee two studies: one involves asthmatics and those without asthma, the other, smokers and non-smokers. “I have friends, and kids of friends, who suffer from respiratory illnesses,” says Ms. Kim, who was in the latter study as a non-smoker. “A common cold hits them twice as hard.”
The research, led by David Proud, has a medically vital purpose. “No healthy person dies of a cold,” says Dr. Proud, a professor in the department of physiology and pharmacology and holder of the Canada Research Chair in Inflammatory Airway Diseases. “But the rhinovirus is a pathogen exacerbating more serious health issues, like asthma, cystic fibrosis, emphysema and chronic obstructive pulmonary disease.”
The Cold Lab studies how the human rhinovirus manipulates the body’s genes. The virus itself doesn’t cause a cold. Rather, cells being attacked by rhinoviruses release proteins called cytokines to trigger an immune system response which stimulates a cascade of cytokines, further activating the immune response. Symptoms include nasal congestion and sore throat as well as sneezing and coughing.
“Our goal was to see how the virus changes the biology of the infected cells,” says Dr. Proud. “The worse the inflammation and swelling, the more potentially devastating the effect for people whose respiratory illnesses mean their lower airway is already swollen.”
Modern gene chip technology shows that about 48 hours after being infected by a rhinovirus, more than 6,500 genes are affected. Dr. Proud’s research has revealed that many genes are changed by exposure to the virus, with some of these effects causing inflammation, while others are part of the body’s antiviral defences.
Dr. Proud’s lab was the first to disclose that an antiviral protein called viperin was very strongly induced when patients were infected and that this protein limits the ability of the virus to replicate and spread.
Ultimately, if the body’s best “virus fighters” can be identified, scientists might be able to boost the body’s ability to produce them or supplement them with a pill or a nasal spray. Humans will still catch colds – and that’s a good thing, because it means we will also develop antibodies to protect us the next time we encounter that particular strain of rhinovirus – but eventually, researchers may find ways to dramatically reduce, or eliminate, the symptoms.
Finding a cure for the common cold would have economic as well as health benefits. Dr. Proud says that as much as 50 percent of total healthcare costs in Canada are associated with treating asthma. More than three-quarters of acute asthma attacks in children are triggered by common respiratory infections, with colds accounting for two-thirds of these. And 70 percent of the costs of treating chronic obstructive pulmonary disease are spent on serious attacks, mostly caused by colds that also tend to produce the most severe and longest-lasting illnesses. A 2010 Conference Board of Canada study estimated that chronic lung diseases cost the country $12 billion in direct and indirect health costs. “If we could boost the body’s ability to fight rhinoviruses,” says Dr. Proud, “it could significantly reduce healthcare costs.”
Volunteers like Ms. Kim are tested to ensure they don’t carry the antibody against rhinovirus 39 and then are infected. After that, they are given a variety of tests over several weeks, including nasal scrapes and washings, breathing tests and two bronchoscopies (inserting a scope into the lungs, administered under sedation).
No wonder it’s not that easy to attract subjects, especially since the university’s Conjoint Health Research Ethics Board doesn’t allow the lab to pay volunteers. (They may be reimbursed for expenses and sometimes a little for lost time at a job, but nothing that would make a raging head cold seem worthwhile if you were in it just for the money.)
“Understandably, people say, ‘You’re going to give me a cold? Why would I want that?’ says Curtis Dumonceaux, a respiratory therapist and clinical research coordinator at the lab. “It can be hard to find people. Most of our volunteers have a sense of altruism. They want to help others in the future, and many of them know someone with a respiratory illness.”
That was the case with Ms. Kim, who admits the whole process wasn’t much fun. “Oh yeah, I had a really good head cold, all mucussy and headachy.” But she adds, “I live with a chronic health issue myself: fibromyalgia. Since I hope there will one day be new treatments for that, I’m willing to help others who suffer from health conditions.”