Universal flu vaccine takes a step closer

A team led by scientists at Dutch vaccine developer Crucell and The Scripps Research Institute in the US says it has identified the first human monoclonal antibodies capable of disabling all influenza B viruses.

The discovery, published in the journal Science, could be a major step forward in the development of a universal flu vaccine.

The research was conducted with collaborators from the Centre of Influenza Research at the University of Hong Kong.

Jaap Goudsmit, director of the Crucell Vaccine Institute and co-author of the study, said: ‘There is a strong need for development of new therapies that go beyond treatment or prevention of infection by single strains, especially with the growing problem of resistance to available anti-viral drugs.

‘A broad-spectrum antibody therapy would be of great benefit for protecting people at high risk of dying from influenza such as senior citizens.’

The discovery of human monoclonal antibodies with broad activity against influenza B complements Crucell's previous discoveries of antibodies against influenza A viruses. Significantly, it paves the way for the development of a universal flu vaccine against influenza A and B, as well as new therapies.

The researchers have discovered the first three human monoclonal antibodies (CR8033, CR8071 and CR9114) with the potential to combat any influenza B virus.

The vast majority of antibodies the human immune system produces in response to an invading flu virus are relatively strain-specific. They recognise parts of the virus that rapidly mutate and change shape. In contrast, the antibodies identified in the new research combat a broad spectrum of virus strains by recognising so-called 'conserved epitopes' on the viral surface: binding sites not prone to mutation and structural change.

The researchers found that the novel antibodies protected mice against normally lethal levels of exposure to influenza B viruses. CR9114 also protected mice against the influenza A virus.

Robert Friesen, deputy scientific director of the Crucell Vaccine Institute and a study co-author, said: ‘The identification and characterisation of monoclonal antibodies with broad neutralising activity against influenza B viruses, together with previously described broadly neutralising antibodies against group 1 and group 2 influenza A viruses bring a universal therapy a step closer, and may guide the design of broadly protective vaccines. In particular, a vaccine that elicits antibodies targeting the CR9114 epitope may provide the ultimate goal of protection against all influenza A and influenza B viruses.’