How scientists cracked a cure for the common cold
Nasal spray being trialled on humans in cutting edge tests
DRESSED in a pristine lab coat, the scientist snaps on a pair of surgical gloves and purposefully approaches the young man sitting in front of him. He puts a quick squirt of spray up the volunteer’s nostril and his work is done.
Now all there is to do is watch and wait.
It might not sound cutting edge, but it is.
The innocuous looking liquid being sprayed up the young man’s nose is a potential vaccine to prevent the common cold. It has been shown to work in mice and rats, stopping them becoming infected with the common cold – and it’s being tested in humans.
A cure for the common cold is one of medicine’s holy grails. It’s something that has eluded scientists for decades, partly because there isn’t just one virus that can cause colds.
In fact, there are around 200, though most colds are caused by three: the rhinovirus, coronavirus and respiratory syncytial virus (RSV), responsible for 80 percent of colds.
“That makes it very hard to find a vaccine that would work against them all or a treatment that could work for them all,” says Peter Openshaw, a professor of experimental medicine at Imperial College London, who has spent the past 30 years researching colds and flu.
“But I think we are on the verge of it, I really do.”
Openshaw heads a team that is testing the new nasal spray vaccine SynGEM, produced by a Dutch biotechnology company.
They are waiting to see if the 36 volunteers produce antibodies – immune cells that kill the cold virus when it enters the body. This will be the sign that the vaccine works.
“Colds can and do kill,” says Openshaw. “Every year, there are many winter deaths, some of which are due to flu, but others are due to common cold viruses that can be fatal to the weak and the vulnerable.”
Normally this is through complications such as pneumonia (inflammation of the lung), but some forms of cold can prove particularly dangerous to babies. More infants are hospitalised by a cold than by any other illness.
And even if a cold is not life-threatening, it can be lifechanging, says Dr Christopher Chiu, a senior lecturer and honorary consultant in infectious diseases at Imperial.
“If an elderly person with pre-existing lung disease who is frail and only just coping at home gets a cold, this might be the thing that leads to a deterioration of their condition. It not only leads to them being hospitalised, but also to their not being able to return home to their independent life.”
So the hunt for a cure is no idle one, and in their cold labs, the scientists at Imperial – one of the leading cold research centres in the UK – have investigated everything from the number of anti-bodies we produce when we catch a sniffle to the amount of nasal mucus we release at the peak of infection.
Each cold virus has a preferred environment in the body.
“Some have more of a focus on the nose and throat, partly because they prefer the lower temperature there” says Openshaw. “That’s why some tend to cause more nasal-type symptoms, such as a runny nose and pain behind the sinuses.
“Others prefer a warmer temperature found in the lungs. Influenza, for example, which is a form of common cold virus, prefers this kind of environment and tends to cause fewer nasal symptoms and more shivers and aches.’
But the Imperial team hope the new vaccine could halt the cold before it’s begun.
“Previous studies for a new vaccine looked at immune cells, or antibodies, in the blood to see how people reacted to cold infections,” says Chiu.
“However, we have found that when antibodies get to the lung or nose, they look totally different and not like their counterparts in the blood.”
Most vaccines are given by injection into the muscle, so the cells that are activated are mainly in the blood. The new understanding about these antibodies in the lungs and nose means scientists have to re-think where the vaccine is given.
“Now it is clear that if you want to fight (respiratory) infections, the vaccine needs to be nearer to the site of the infection,” says Chui. And that, he says, means giving it as a nasal spray. “This will make antibodies in the nose, so they can kill the virus before it starts to replicate.”
Remarkably, there is already a treatment. It is given to atrisk babies to help prevent RSV. It’s been around for a few years, though you are unlikely to have heard of it.
Palivizumab is given as monthly injections from October to March in the UK to protect at-risk infants, such as premature babies, with under-developed lungs against RSV. It is a form of antibody that stops the virus from entering the child’s cells and it can reduce the risk of hospitalisation by as much as 45 percent, according to UK studies.
“It is very expensive so it is only given to high-risk children,” says Dr Fiona Culley, a lecturer in respiratory infections. – Daily Mail