San Diego scored a twofer this week, with two groups of scientists making similar discoveries of flu-fighting antibodies. The Union-Tribune is reporting today that researchers at The Scripps Research Institute in La Jolla have, along with a Dutch pharmaceutical company, discovered an antibody that kills several viruses, including the bird flu. The findings were published in Science Express, the online version of the journal Science.
The Scripps news comes just days after an almost identical announcement, which we wrote about Sunday, by scientists down the road at the Burnham Institute for Medical Research. The Burnham team collaborated with the Centers for Disease Control and Prevention and Harvard’s Dana-Farber Cancer on the discovery of a separate antibody that also attacks the bird flu and other flu viruses. Their results were published Sunday in the journal Nature Structural & Molecular Biology.
Both sets of researchers say their discovery could lead to powerful antivirials, and possibly even vaccines, that would make flu pandemics at thing of the past. And the key to both discoveries was identifying antibodies that target the stems of the lollipop-shaped molecules that are packed tightly on the outer surface of the flu virus.
Current antivirals and vaccines target the heads of the molecules because they are the most visible to the body’s defenses. However, targeting the head is ineffective in the end because the head is constantly mutating. This is why a new flu vaccine has to be developed every year.
The stem is a different story. It is a far more complex part of the virus and because of its complexity does not mutate like the head. So if the stem can be neutralized, the virus can’t fuse with cells in a person’s body and make them sick. But until now, researchers have not been able to develop such antibodies because the virus stem stays hidden under the head, and unrecognizable to the antibodies that fight the virus
Here are more details about the Scripps finding from the UT:
“This is very exciting because it marks the first step toward the Holy Grail of influenza vaccinology — the development of a durable and cross-protective universal influenza virus vaccine,” said Ian Wilson, the Scripps study’s senior investigator. “Such a flu vaccine could be given to a person just once and act as a universal protectant for most subtypes of influenza, even against pandemic viruses.”
The key antibody, known as CR6261, was derived from donor blood by Crucell scientists. They initially thought CR6261 might be rare, but they have since found other donors with it. They now suspect that CR6261 might be relatively common, but that the human body doesn’t generally produce enough to use it efficiently.
The research was conducted on mice. Treated with CR6261, the mice recovered from lethal doses of bird flu as late as five days after infection. Still, Wilson cautioned that more research and testing are needed, including clinical trials, before either an antibody-based flu treatment or a universal vaccine becomes available for human use.
Wilson said his team was obliged to withhold its announcement because of a media embargo mandated by the journal Science. “Believe me, it was very frustrating. If we could have said something earlier, we would have.”