Phages can be used to deliver vaccines with pinpoint accuracy

A free-floating virus is not really a virus; it is a set of molecules with an ambition to get inside a living cell and make copies of itself. A human being is one of the best available assembly lines for certain viruses, which is why we need to be careful when in their vicinity.

However, not all viruses are dangerous to human beings and scientists are now looking at some of them as allies rather than invaders. With the right amount of coaxing, a virus can become one of the most useful things that we have on this planet.

Scientists are now trying to use viruses to cure bacterial infections, manufacture materials, as messengers of genes and vaccines and so on. Nobody has perfected any of these techniques but scientists are making such rapid progress in this field that within a year or two, we could see the first commercial products with viruses. Within 10 years, viruses could be extensively used for many pharmaceutical and industrial applications.

In Bangalore, Gangagen Biotechnologies is using a type of virus called phages to cure bacterial infections. Gangagen’s subsidiary in Ottawa, Canada, will launch a phage-based line of therapy later this year for veterinary infections. In Silicon Valley, a start-up called Cambrios is developing electronic materials using viruses and will launch the first commercial product this year. In many other labs around the world, biologists are using viruses in clinical trials for delivering vaccines. Recently, scientists at the Massachusetts Institute of Technology (MIT) also used viruses to clean up bacterial films in medical equipment.

First seen in the river Ganges, phages are found naturally in many places on earth. They get inside bacteria and make copies of themselves. Specific phages attack specific bacteria, and are the primary reason bacteria have not dominated the planet. However, using phages to treat bacterial infections presents many challenges. They scatter bacterial toxins when they come out, which is dangerous for the hosts of the bacteria. Since phages have been known for a long time, private companies cannot get patents on them, a commercial disincentive.

Gangagen is not the only company to use phages for therapy, but it has solved a few of these problems with some intellectual property. It has found a way, through genetic engineering, to make the phage kill the bacteria but remain inside. It has more patents, one of them to use bacteria — killed by phages — as a vaccine. Its first commercial product will, however, be for curing infections in cattle. Human applications will come two or three years later. Says J. Ramachandran, CEO of Gangagen: “We are looking at topical applications first.”

Before phages are approved for human therapy, they might be used to deliver vaccines to cells with pinpoint accuracy. This is in a particular kind of vaccine called DNA vaccine, where the gene that makes the antibodies integrates with the genetic material of the host. In clinical trials, once again primarily for veterinary applications, viruses have delivered vaccines inside the host DNA. However, there are still some safety concerns to be dealt with in using viruses for vaccine delivery.

Recently, researchers at MIT and the University of Boston used genetically engineered phages to clean up films in medical equipment and other places. Such films form regularly inside the mouth, inside food processing machines, medical equipment and almost anywhere. They are hard to find and harder to eliminate. MIT scientists found that they could eliminate 99.99 per cent of infections through their engineered phage.

In California, scientist Angela Belcher uses the bacteriophage M13 to make tiny wires and electrodes. She had set up her company Cambrios in Santa Barbara in 2002. The company is still in stealth mode but is expected to release its first product soon. It would be one of the first uses of viruses to make useful substances that are too small to manufacture conventionally. “As we make things smaller and smaller, a biological approach to manufacturing is the best,” says Alok Srivastav, CEO of Nidan, a company housed inside the University of California, San Francisco. One day, even integrated circuits will be too small to be made in any other way, and that day may not be far off.