# 2848
Thus far, the creation of H5N1 vaccines for humans has been complicated by the low immune response that test subjects have shown to the antigens produced.
Practically all of the vaccines we've seen to date will require two shots, 30 days apart, to confer reasonable immunity.
Now, scientists in Hong Kong have produced a new type of H5N1 vaccine, by piggybacking 5 proteins from a pair of H5N1 viruses onto the existing, and relatively easy to produce, smallpox vaccine.
This vaccine is adjuvanted by the addition of immune stimulatory cytokine IL-15.
Despite the hopes for this approach, testing has only been done on mice at this point. More animal testing (first on ferrets, then monkeys) will be required before human clinical trials can begin.
In other words, this vaccine, like so many others we have heard about in the past few months, is still years away.
This from Reuters.
Experts fight H5N1 bird flu using smallpox vaccine
01 Mar 2009 08:02:47 GMT
Source: Reuters
By Tan Ee Lyn
HONG KONG, March 1 (Reuters) - Scientists in Hong Kong and the United States have developed an experimental H5N1 bird flu vaccine for people by piggybacking it on the well-tested and highly successful smallpox vaccine.
Initial tests on mice showed the vaccine to be highly effective, they told a news conference in Hong Kong on Sunday.
"It produced a lot of (H5N1) antibodies and the speed of antibody response was far higher with this strategy than the Sanofi one," said Malik Peiris, a microbiologist and bird flu expert at the University of Hong Kong.
Peiris was referring to Sanofi-Aventis's <SASY.PA> H5N1 bird flu vaccine for humans, which has been approved for use in the United States.
In an article published in the current Journal of Immunology, the experts from Hong Kong and the U.S. National Institutes of Health described how they inserted five key components of the H5N1 virus into the smallpox vaccine.
"We put in many other proteins into that vaccine; we are using it like a carrier, if you like, a piggyback," Peiris said.
The vaccine uses a Vietnam strain of the H5N1 virus and appeared to be broadly protective. Mice which were inoculated with it successfully fought off an Indonesian strain of H5N1, according to the scientists.
