A cure for the common cold could be on the horizon, according to new research.
Experiments on mice and monkeys have found dozens of different viruses can be mixed together to create a ‘one size fits all’ style jab.
Scientists now hope to try their ‘cocktails’ on human volunteers, which should be possible because they are not dangerous.
The main cause of colds are rhinoviruses, but the problem is there are more than 100 different types, suggesting the quest for an immunisation programme was unrealistic.
It was always felt the human body cannot build up resistance to so many, so they can cause illness again and again.
It is much more difficult than, for example, curing smallpox, a single stable virus where one could develop a vaccine to overcome the disease.
But now scientists say the immune system can, by using vaccines that combine dozens of varieties of rhinovirus at once.
Professor Martin Moore, of Emory University in the US, said: “We think creating a vaccine for the common cold can be reduced to technical challenges related to manufacturing.”
Writing in the journal Nature Communications, he said vaccines that combine dozens of varieties of rhinovirus are effective in stimulating antiviral antibodies in animals.
Prof Moore and colleagues are making the case that a vaccine against the common cold is achievable.
He said there are other viruses that also cause colds, but the rhinovirus varieties exacerbate asthma attacks too.
And Prof Moore said that although they come in many forms, they do not change to the same extent that flu does.
The viruses attach themselves to the cells lining the nose, causing minute areas of damage.
It is the body’s own white blood cells that cause the symptoms of a cold. They are attracted to the nose when it is infected and release powerful natural disinfectant chemicals to kill the invading viruses.
In the study the cocktail of inactivated rhinoviruses stimulated neutralising antibodies against all 25.
And a bigger mixture of 50 types did exactly the same thing in tests on rhesus macaques.
Researchers showed in the 1960s it was possible to vaccinate people against one variety of rhinovirus and prevent them from getting sick when exposed to samples of the same virus.
The trouble was the sheer diversity of rhinoviruses - or that is how it appeared at the time.
Prof Moore said: “It is surprising nobody tried such a simple solution over the last 50 years.
“We just took 50 types of rhinovirus and mixed them together into our vaccine, and made sure we had enough of each one.
“If we make a vaccine with 50 or 100 variants, it is the same amount of total protein in a single dose of vaccine. The variants are like a bunch of slightly different Christmas ornaments, not really like 50 totally different vaccines mixed.”
Antibodies generated in response to the vaccine were tested for their ability to prevent the virus from infecting human cells in culture. But the vaccines could not be tested for their ability to stop animals from getting sick.
Prof Moore added: “There are no good animal models of rhinovirus replication.
“The next step would be human challenge models with volunteers, which are feasible because the virus is not very pathogenic.”
On any day from September to March at least 50 million people worldwide are suffering from cold symptoms. In a lifetime we suffer from more than 200 bouts of common cold, each lasting five to six days.
Although the majority of cold sufferers can easily shake off their symptoms, approximately four million children worldwide die of acute respiratory infections, mainly in the third world.