Scientists have found that a drug, called DMXAA, originally developed as anti-tumor agent, also enhances the ability of flu vaccines to ward off this deadly virus.
Their study suggests that DMXAA could assist flu vaccines by causing the body to produce its own antiviral proteins, called interferons, which interfere with the virus's ability to spread.
In addition, DMXAA may be a useful antiviral therapy to treat newly emerging strains of the flu for which a vaccine has not been developed.
"We are hopeful that DMXAA or similar agents can be used ultimately to blunt the impact of yearly influenza outbreaks, and perhaps, for other virus infections as well," said Stefanie Vogel at the University of Maryland, co-author of the study.
In the study, Vogel and colleagues infected mice with a mouse-adapted influenza strain.
When given DMXAA three hours before or after infection and then two days later, the infection was significantly less severe.
In addition, they found that DMXAA protected cells from flu strains that are resistant to Tamiflu, one of the most advanced anti-flu drugs on the market.
These discoveries suggest that DMXAA could potentially enhance the efficacy of current flu treatments and vaccines, and perhaps treat other viruses or bacteria.
To be sure that DMXAA led to increased production of interferons, the researchers also tested it in mice that lacked a gene needed to produce interferon, and found that these mice received no benefit from DMXAA.
The study was published in the March 2011 issue of the Journal of Leukocyte Biology.