Natural antibody found to prevent broad variety of influenza viruses

A new report by scientists at The Scripps Research Institute and Dutch biopharmaceutical company Crucell describes a natural antibody that can prevent or cure infections from a broad variety of influenza viruses in animal tests.

The influenza subtypes neutralized with the new antibody include H3N2 and seasonal and potentially pandemic strains. The scientists wrote that this antibody could lead to a universal flu vaccine that would get around the basic flu-virus defense mechanism that requires annually changing flu vaccines.

"Together this antibody and the one we reported in 2009 have the potential to protect people against most influenza viruses," Ian Wilson, who is the Hansen Professor of Structural Biology and a member of the Skaggs Institute for Chemical Biology at Scripps Research, said. Wilson is also a senior author of the new paper with Jaap Goudsmit, Crucell's chief scientific officer.

The antibody CR6261, discovered in 2009, binds with one of the more vulnerable and relatively unvarying part of the flu virus. In mice, it was found to prevent or cure an otherwise lethal infection of around half of flu viruses. The antibody is about to begin tests in human volunteers.

Researchers at Crucell subsequently looked for an antibody that could neutralize some or all of the remaining flu viruses unaffected by CR6261 and found CR8020. CR8020 neutralizes a range of human-affecting flu viruses in lab dish tests and in mice, including H3 and H7. The new antibody binds to an HA protein that is even closer to the viral envelope than the CR6261 antibody binds.

"This would mainly be useful as a fast-acting therapy against epidemic or pandemic influenza viruses," Wilson said. "The ultimate goal is an active vaccine that elicits a robust, long-term antibody response against those vulnerable epitopes; but developing that is going to be a challenging task."