Shares of biotechnology firm Novavax (Nasdaq: NVAX) leaped in morning trading following an announcement that its vaccine against avian flu seems effective in small animals.

Novavax' virus-like particle (VLP) vaccine triggered a robust immune response and provided protection against the H9N2 strain of avian influenza, according to pre-clinical data published in the online edition of the journal Vaccine.

This is the first time Novavax has measured the efficacy of our VLP vaccine against a live virus challenge in the very important ferret model, said Dr. Rick Bright, vice president at Novavax. These data are very encouraging because the ferret is a more predictive model for efficacy in humans.

Virus-like particles mimic the three-dimensional structure of a virus but do not contain genetic material, so they cannot replicate or cause infection.

All of the data we’ve accumulated to date indicate that our VLP vaccines have the potential to provide protection against various strains of avian influenza, Bright said. We are particularly encouraged by these ferret data and look forward to evaluating the immunogenicity of our H5N1 VLP vaccine in the clinic later this year.

Shares of the firm rose sharply, rising 46 cents, or 17.8 percent, to $3.05 by afternoon trading on the Nasdaq Stock Market.