Is a cure for the common cold on the way?
Published: 20th Dec 2011 12:25:49
In the northern hemisphere, cold and flu season is upon us. But the coughing, wheezing and spluttering masses that hit the streets each winter could, some scientists hope, soon be a thing of the past.
The reason for this optimistic thought is the progress being made towards the creation of a drug known as an "antiviral".
Just as antibiotics kill many different types of bacteria, antivirals could kill multiple viruses, from the ubiquitous cold and flu to the life-threatening hepatitis virus and HIV. It could even prove crucial in the case of viral epidemics like Sars and bird flu.
Existing antiviral drugs are tailored to specific diseases - HIV, hepatitis and certain types of flu for example. Vaccinations are also very virus-specific and have to be redeveloped at great cost as a virus evolves.
But Todd Rider, a research scientist at the Massachusetts Institute of Technology, is developing an antiviral drug called Draco, which has proven successful against all 15 viruses to which it has been applied in lab trials with human tissue and mice.
These include the common cold, H1N1 or swine flu, a polio virus, dengue fever and the notorious and fatal Ebola virus.
To produce it, Rider took an unusual approach, "wiring together" two natural proteins - one that detects virus entry, and another that acts as an in-built suicide switch to kill the infected cell.
"I studied both biology and engineering back in the dark ages and really wanted to combine those studies," he says.
Natural proteins in an infected cell detect the presence of a virus. These proteins are sensitive to double stranded RNA, a genetic molecule unique to and present in nearly all viruses.
Todd Rider has taken one of these natural proteins and bound it to another natural protein - also present in all cells - that triggers cell suicide.
To help the new protein penetrate a cell, he added a feature that imitates part of the HIV virus, borrowing that virus' ability to break into cells.
Once administered, the drug travels to every cell in the body but it will only activate in infected cells.
In a matter of hours, the RNA-sensing part of the drug detects the virus and activates the cell suicide part. When the host cell dies, so does the virus.
"Everyone in both departments thought I was crazy."
The dream of a broad-based antiviral drug has for years been a holy grail for microbiologists.
Recent developments in biotechnology - especially the ability of computers to analyse reams of information on DNA and the genetic make-up of viruses - has allowed for great leaps in scientific understanding of how these micro-organisms work.
This has brought a few researchers closer to the goal of a broad-based antiviral, targeting the problem in several different ways.
Last year, a break-through study at Cambridge University showed that cells have an internal system which fights and kills viruses. It was previously thought that once a virus succeeded in entering a cell, infection was inevitable.
The author of this study, Dr Leo James is now working on creating antiviral drugs that can latch on to a virus and destroy it inside the cell.
At Mount Sinai Medical School in New York, Professor Peter Palese has developed an antiviral drug that has so far proven very successful against influenza, though less so against other viruses.
And in a laboratory at the other side of the US, Dr Benhur Lee stumbled across a drug that seemed to be effective against several viruses including various pox viruses and Ebola. He soon realised it only worked against viruses that shared a distinct characteristic, a greasy outer membrane or lipid envelope.
Dr James maintains some scepticism about Rider's study.
"It is potentially very exciting but because the results are so unusual and because it was published in an unusual journal it needs to be proven by others," he says.
PLoS One, the online journal which published the paper doesn't have the peer review system used by other journals and encourages ideas that challenge established thinking.
Draco appears to have a greater range than its rivals, but it will be several years before Draco can be tested on humans. First the drug will have to go through several rounds of testing on larger mammals.
"Translating from the lab to people is really quite hard," says immunologist Hugh Pennington, Professor Emeritus at Aberdeen University.
Viruses and human cells become closely linked on infection, as a result there are many possible side-effects of a drug like this.
In the 1950s scientists thought they had come up with a similar broad-spectrum antiviral wonder drug, interferon.
In 2007 the results of a 20-year study showed that people who took vitamin C every day were no less likely to get a cold than those who didn't. Vitamin C also had no effect on the length of the illness.
Eating chicken soup to combat a cold is an age-old remedy, dating back to 12th Century physician Maimonides - and it may work. Drinking warm liquid soothes the nasal passages while the soup seems to act as an anti-inflammatory. Protein from chicken and antioxidants from vegetables also help the body make virus-killing antibodies.
An extensive study into the herb echinacea showed that people who took the supplement regularly were 65% less likely to get a cold. But later studies have discredited the herb, some claiming it increases mucus production and enhances cold symptoms.
In 2005 a study in the US showed that gargling salt and water three times a day reduced infection of the upper respiratory tract by 40% - but once someone got sick it accentuated symptoms.
The flu vaccine is the only proven medical protection against flu, though it has no effect on the common cold. Contrary to popular myth, the vaccine cannot actually give you the flu. It injects a dead form of the virus into the body.
The drug causes an infected cell to secrete a warning signal to other cells, allowing them to build up their natural defences. However it also triggers the immune system to send white blood cells to the infection, which can cause inflammation of the area, fever, aches and pains.
"Interferons are fantastic drugs," says Wendy Barclay, chair of influenza virology at Imperial College London.
"They are still used to today, to treat hepatitis C virus. But if you had a mild virus infection like a common cold you would not want to take interferon to deal with it because it would make you feel horrible, even worse than the cold was making you feel.
"The problem with using that same approach today to develop a broad-spectrum antiviral is always the worry that something in your strategy is going to trigger that same response."
Like interferon, Draco is a protein and has the potential to provoke an immune response. This could be especially problematic when the drug is administered a second time. But no immune response has been observed in mice so far.
For the average human, who suffers through a cold up to four times a year, antivirals could be the answer to days of misery - for businesses they could save weeks of lost man hours.
But for those on the front line of healthcare it could mean much more.
A broad-based antiviral could obliterate the threat of a global pandemic and mitigate health scares such as that caused by the Sars virus in 2002 or bird flu in 2009.
"No one can say when the next pandemic will occur, it may be next year or it may be in 100 years' time," says Hugh Pennington.
"We're still in the niggling worry scenario even when we are very optimistic… If we had a wonder drug like Draco might be, we could sleep much easier at night."
Find out more about Todd Rider's work and the search for a broad-based antiviral on Discovery from the BBC World Service. Listen to the programme here.
At 14:05:21 in TechnologyChinese computing giant Lenovo has shown off what it hopes will be a rival to Google Glass.
At 14:02:01 in SportPeterborough United have signed former Sunderland and Tottenham goalkeeper Ben Alnwick on a three-year deal.
At 13:55:07 in HealthA hunt has been launched in Sierra Leone's capital, Freetown, for a woman with Ebola who was forcibly removed from hospital by her relatives.
At 13:54:40 in EntertainmentTicketholders for the latest Secret Cinema screening of Back to the Future have yet to be told whether the event will resume, after Thursday's opening night was cancelled.
At 13:53:08 in ScotlandA man with two previous convictions for assault and robbery has been jailed for eight years over a botched armed raid.
At 13:52:31 in WalesA Pembrokeshire secondary has been put in special measures after failing to improve enough in the past year.
At 13:52:02 in EnglandPlans for a £13m development at Dorset County Museum have been unveiled.
At 13:50:16 in EnglandComedian and actor Johnny Vegas has been awarded an honorary doctorate from a Lancashire university.
At 13:46:01 in SportScotland's Ross Murdoch again got the better of countryman Michael Jamieson at Tollcross International Swimming Centre, this time in the 100m breaststroke heats.
At 13:40:23 in EnglandThe family of a Saudi Arabian student murdered in Essex, has urged her killer to hand themselves in.
Harvard CitationBBC News, 2011. Is a cure for the common cold on the way? [Online] (Updated 20th Dec 2011)
Available at: http://www.ukwirednews.com/news/211974/Is-a-cure-for-the-common-cold-on-the-way [Accessed 25th Jul 2014]
News In Other Categories
A protest against the impact of conflict on medical staff in Gaza has taken place outside the Royal Victoria Hospital in Belfast.
A hunt has been launched in Sierra Leone's capital, Freetown, for a woman with Ebola who was forcibly removed from hospital by her relatives.
With the doors to its brand new £1million training centre officially open, one of the UK's leading apprentice training providers, Bristol based S&B Automotive Academy, is showcasing its world-class facilities by launching a series of foreign student exchanges for the first time in its 41-year history. To get a flavour of what life is like as an apprentice in the UK, the Academy hosted 16 apprentice engineers and bus drivers from the G9 Automotive College in Hamburg, Germany, as part of a Europe-wide vocational training initiative called the ‘Leonardo Programme’ with support from the European Social Fund. In a reciprocal arrangement, S&B will be sending nine apprentices to Germany during February 2012 so that they can get an appreciation of life in the automotive industry on the Continent. A further three German exchange groups are being planned for next year. Designed to assist the development of vocational skills and training across Europe, including work placements for trainees, the Leonardo Programme has a budget of €1.75bn, which is helping to encourage UK organisations to work with their counterparts abroad. In what is expected to be another challenging year for employers in the UK automotive sector, S&B’s Chief Executive, Jon Winter, claims that the exchange initiative will bring many benefits to the Academy and its apprentices: “In a world of global automotive brands, it’s important for our learners to understand the international context of the industry they have chosen to make their career. This new exchange programme will enable apprentices and Academy staff alike to achieve a better understanding of the challenges and opportunities within the automotive arena in Europe. With the Academy’s influence also extending to the USA and Asia, there’s every possibility that this initiative could move further afield in the future.” Continued Winter: “The need for skilled technicians across the world is on the increase and we actively encourage our apprentices to look at broader horizons during their training. Many of them have already learned the phrase ‘Vorsprung durch Gelehrtheit’, quite simply, ‘Advancement through learning.” In the 2010/11 academic year, S&B doubled the number of successful Apprenticeships over the previous year with some 350 apprentices graduating from the Academy. At the same time, achievement levels reached an all-time high with an overall success rate of 85%. For those learners on the Advanced Apprenticeship three-year programme, success rates were even higher, at over 98%. PHOTO CAPTION: As part of their exchange visit, S&B Automotive Academy arranged for the German apprentices to visit Hampshire bus operator, Bluestar, at its Barton Park depot. The students are pictured with S&B’s Andy West (3rd right) and Steve Prewett, Bluestar’s Area Engineering Manager (2nd right). Ends http://www.sandbaa.com
Ticketholders for the latest Secret Cinema screening of Back to the Future have yet to be told whether the event will resume, after Thursday's opening night was cancelled.
A report by MPs suggests sexist attitudes, boring lessons and "gratuitous derogatory remarks" made by media commentators put women off sport.
A Pembrokeshire secondary has been put in special measures after failing to improve enough in the past year.