For all the good that vaccines have brought the world, their development has remained a lengthy, often trial-and-error based activity. But a new discovery by Penn State biochemists could point the way to dramatic improvements in this process.
Researchers have isolated an amino acid inside the polio virus that controls how the strain replicates itself in the body. By replacing it, they were able to create a harmless mutated version, as would be useful in creating a vaccine. The amino acid appears to play the same role in other viruses, they said.
A viral infection process is essentially a race. A virus first enters a cell, and turns it into a little factory creating new versions of the invader. If the immune system can isolate and kill the viruses faster than they replicate themselves, then the infection is stopped. If the viruses win this race, they break through the sickened cell's walls, and the infection spreads.
Vaccines work by creating a weakened version of the virus that replicates slowly or not at all, essentially allowing the immune system to prime itself. Once the body know s what to look for, the white-hatted cavalry can come riding to the rescue much sooner.
Most viruses use an enzyme called polymerase to help regulate the speed and accuracy of replication. The amino acid isolated by the Penn
State researchers controls this process as part of the polymerase.
If this discovery is indeed applicable to other viruses, it could substantially speed the process of vaccine creation. Biochemists could be given a much better idea of exactly how to weaken existing viruses, easing the trial-and-error aspect considerably, the researchers hope.
"We have successfully tested this technique with polio virus," said
Craig Cameron, the Penn State professor leading the research team, in a press release announcing the discovery. "And we think it is applicable to most other viruses."
This could particularly helpful in developing fast responses to quickly mutating viruses such as SARS, influenza, or the West Nile, or for dangerous outbreaks of strains like Ebola or smallpox that could be used in biological warfare, the researchers said.
(Photo: The H5N1, or Avian Flu virus. Source: CDC)
