The Danish pharmaceutical firm Bavarian Nordic announced last week that a single dose of its next-generation Imvamune smallpox vaccine can protect mice against a virus similar to smallpox (see GSN, Oct. 3, 2007).
Mice that received the third-generation vaccine could withstand same-day exposure to lethal levels of Ectromelia virus, a poxvirus strain that produces an infection similar to that seen in humans exposed to smallpox. Mice were also protected if they received the vaccine up to three days after exposure, leading the company to bill the vaccine as the first post-exposure treatment effective in test animals.
"With Imvamune we can offer a safer vaccine and a solid protection both before and after exposure," said Bavarian Nordic head Anders Hedegaard in a press release. "No other smallpox vaccine has shown to offer these important features."
Researchers noted that some immune system-suppressed mice died after being injected with Dryvax, an older smallpox vaccine (see GSN, March 3; Bavarian Nordic release, April 10).