Influenza
The cure we’ve been waiting for



By Callan Emery

If all goes according to plan, in about three years we may be able to simply spray an aerosol up our noses and never again be affected by the dreaded flu. That means no more runny noses, headaches, sore throat, muscle pains and all the well-known and much loathed symptoms of a bout of influenza, a cure for which has remained so terribly illusive.

The development also holds the potential to put an end to the fear that is currently gripping the world as it waits in edgy anticipation for the next killer flu pandemic to strike.

After more than 20 years of research Professor Nigel Dimmock and his team of researchers at the University of Warwick in England appear to have developed the ultimate cure for influenza.

It is a breakthrough that is making headlines in the world’s media and, if the positive results of laboratory tests are borne out in human trials, will provide protection against all strains of influenza type-A, and that includes the much-feared H5N1 strain of the virus.

What the researchers have developed is an entirely new method of protecting against flu and their tests in animals have shown remarkable results. Prof Dimmock and his team have developed what they are calling a ‘protecting virus’.

Prof Dimmock explains: “Vaccines only work against a specific virus – they are highly specific and have to be regularly updated. More recently anti-viral drugs have been developed – the best known is Tamiflu. However, it is certain the viruses will gain resistance to these drugs. So how long it will be effective for we really don’t know. “What we’ve invented is completely different. It is a ‘protecting virus’.

Basically it is a virus, but it is a virus that has lost a bit of its DNA. So it is dead. It cannot multiply,” Prof Dimmock said, adding, “We have not manipulated the genetics of this virus. It is a natural product that we have selected.

“Although the virus is dead, it has the property to protect us. What it does is interfere with the replication or multiplication of the infecting virus. ‘Protecting virus’ inhibits it, so the virus only ticks along instead of bounding along producing millions of new infections,” Prof Dimmock said in an interview at Warwick University. “It slows [replication] down so that our own natural defences can take care of the infection. In the best case scenario we don’t even know we are infected.

We get the infection but it is entirely sub-clinical. We get no symptoms at all.” He said the ‘protecting virus’ is delivered either as nasal drops or nasal spray and it acts instantly. “As it is a virus, although a dead one, it has all the properties of a regular virus.

It goes to the same cells as an infecting virus. It sits there and doesn’t reproduce.” When an infecting virus enters the cell the protecting virus interferes with it and inhibits replication of the infecting virus, in essence preventing further infection. Prof Dimmock explained that the protecting virus degrades at a constant rate so the period of protection it offers will eventually fade out. “In experiments we’ve done we can show that protection lasts in excess of six weeks,” Prof Dimmock said.

Existing vaccines

Existing vaccination methods depend on stimulating the body’s immune system, so that white blood cells produce antibodies that attach to the surface of the virus and start the process of killing it. This works well for many diseases, such as smallpox, polio and measles, but is much less effective with influenza, as the coat of the flu virus is continually mutating.

Vaccination against one strain of flu, for instance H3N2, is totally ineffective against another, such as H5N1. This is especially problematic when a new pandemic strain emerges, as all existing vaccines are likely to be totally ineffective.




Protecting virus

The genetic material of a flu virus consists of eight individual segments of single stranded RNA. Prof Dimmock’s ‘protecting virus’ has a specific deletion of around 80% of one of these eight RNA strands. This deletion makes the virus harmless and prevents it from reproducing by itself.

However, if it is joined in the cell by another infecting influenza virus it prevents the infecting virus from rapid replication. This slows the progress of the new infection and allows the body’s natural defences to fight the new invader.

“Interestingly, at the same time [as it slows replication of the infecting virus] there is an additional effect and that is that there is a low grade multiplication of the infecting virus which our immune system deals with and in dealing with it, it is stimulated to produce the immunity that will protect us against any recurrence of infection by that virus. In effect it turns the virus into its own vaccine,” Prof Dimmock said. Research indicates that the ‘protecting virus’ will have the same beneficial effect on any strain of influenza type-A. “There are 144 strains of influenza. Our tests in the laboratory have shown that the ‘protecting virus’ protects against all the strains we have tested – although we have not tested all 144 strains. “What we know about the range of protection and how it protects, we predict it will protect against all strains of influenza-A,” Prof Dimmock said. This is because mutation of the coat of the virus is irrelevant to the protection process. “It doesn’t work like a vaccine simulating specific immunity, rather it goes to the core of virus multiplication and disrupts it,” he said.

Prophylaxis

‘Protecting virus’ promises to be a highly effective tool when combating the spread of any new strain of influenza type-A virus, as well as existing strains. The researchers have shown that it can be used as a prophylaxis, without the need to tailor it to a particular flu strain or mutation, as well as a treatment.

This has obvious benefits when dealing with a sudden influenza pandemic, as one would not need to know the exact make-up of the new influenza strain before providing the protecting virus as is the case with vaccines. In addition it protects instantly, whereas protection generated by conventional flu vaccination takes two to three weeks to become fully effective.

Lab tests

Laboratory experiments show that a single dose of protecting virus can be given six weeks before an infection with flu virus and still be effective. This could also have a substantial advantage over anti-viral drugs that only give less than 24-hour protection.

Another advantage is that influenza virus does not appear to become resistant to ‘protecting virus’, a problem with anti-viral drugs. ‘Protecting virus’ is easy to administer as it targets the same cells as any other flu virus and uses the same method to enter the cell.

In the lab, researchers administered it by squirting a drop of saline containing the ‘protecting virus’ up the nose of the lab animal. However, aerosol administration, used already for some vaccines, would be another way.

Vetinary application

The protecting virus could also be a useful treatment for domestic animals. Flu is a major problem in race horses and domestic horses. Ducks get a gut infection and chickens a combined gut and respiratory infection. It may be possible to simply deliver the ‘protecting virus’ to them in their drinking water.

Commercialisation

The Warwick research team has now filed a patent on the ‘protecting virus’ and they are exploring ways of taking ‘protecting virus’ through human clinical trials and testing on birds.

The university has established a company – ViraBiotech – to help advance those aims, which will involve rigorous testing in a wide range of animals and humans using a wide range of influenza strains. “We haven’t yet done the experiments in people.

This is the next step as tests in the lab are virtually complete,” Prof Dimmock said. He said he was confident the clinical trials would run smoothly. “It is a normal flu virus, I expect the clinical trials to be fairly routine. We don’t anticipate that there will be any problems of toxicity,” he said. Speaking to Middle East Health, Richard Ferns, a spokesperson for the research team, said clinical trials were likely to begin this year and, if all goes smoothly, they expected them to take about three years before completion and the first commercial production of ‘protecting virus’.
 

                                  
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