Doctors have used vaccines now for more than a century to help prevent people from catching many different kinds of diseases, from smallpox to the flu. Now some scientists in Australia say they've found something to make vaccines perform better.
Stephen Turner has been working on ways to make flu vaccines more effective - with an eye to creating a better way to stop a possible pandemic of avian influenza.
The University of Melbourne microbiologist explains how a vaccine combats a virus.
"The way that it works is it induces what we call antibodies, and these are produced by the immune system, and what they do is they [attach] to the outside of the flu virus, and they neutralize it. That is, they prevent infection," Turner says.
Antibodies comprise only one part of the immune system. The other part is the T-cell system. One kind of T-cell can see when a virus has gotten inside a cell and infected it. Turner says scientists call these "killer T-cells."
"They're what we call the hit man of the immune system" he says. "They're the ones that can recognize that a cell is infected. They can destroy it, and then that's removed from the body along with any of the virus that's inside it."
Traditional vaccines prompt the body to produce antibodies but are not very good at inducing the immune system to create killer T-cells. But Turner says he and his colleagues have found a specific protein that can be added to a vaccine that encourages the body to develop killer T-cells.
"Its job or its role is to basically augment the effectiveness of inducing immune response," he says.
Turner says this protein can be added to the annual flu vaccine, but he's thinks the compound's real value will be to help make a potential avian influenza vaccine stronger.
"And the reason is, because the components recognized by these killer T-cells are shared. The same components are present in, for example, the 1918 Spanish flu, as they are in current circulating flus," he explains. "So the aim is just to try to induce this immunity and provide a little of immunity, hopefully keeping an epidemic or pandemic in check."
Turner says using this protein was very successful in mice. It is already approved for use in humans, so Turner believes it could find its way into a human vaccine within five years.
His research is published in the journal, the Proceedings of the National Academy of Sciences.