Vaccines, which consist of virus-like particles (VLPs) may be able to provide stronger and longer-lasting protection against flu viruses, according to researchers at the University of Pittsburgh.
VLP vaccines can be developed and produced twice as quickly as conventional vaccines, the researchers said.
In early clinical trials, VLP vaccines appear to provide complete protection against both the H5N1 avian influenza virus and the 1918 Spanish influenza virus, said Ted Ross, an assistant professor at the University of Pittsburgh's Center for Vaccine Research.
Adopting the new vaccine strategy may allow public health officials to respond more quickly to emerging influenza pandemics, say researchers.
The current injectable vaccine for seasonal influenza is a trivalent, inactivated vaccine. It consists of three different influenza strains that are grown in eggs and then inactivated, or killed, by chemicals that break them into tiny pieces.
Because they no longer look like the circulating virus, conventionally made vaccines strains do not elicit as strong an immune response as VLP vaccines.
VLPs can be quickly and easily produced in several ways, including growing them in cell cultures or in plants.
Also, if the genes in the disease virus are identified, then researchers can generate particles for a vaccine without an actual sample of the agent.
"The sequence for the recent H1N1 'swine flu' virus was online and available to scientists long before physical samples could be delivered," r. Ross said.
"It would have been possible to produce VLPs in quantity in as little as 12 weeks while conventional vaccines require physical samples of the virus and production can take approximately nine months," he added.
The study has been presented at the 109th General Meeting of the American Society for Microbiology in Philadelphia.