Researchers are close to developing a “super antibody” against flu that could be used as a universal treatment and pave the way for the development of a universal vaccine against the disease that affects billions of people every year.
The treatment is expected to save lives, reduce pressure on intensive-care units during flu epidemics and save millions of pounds of NHS money. It is the first time a single antibody has been found effective against all strains of influenza A, the most common type which is responsible for global pandemics.
Flu is difficult to control because it presents a shifting "target" to vaccines by mutating into new forms. As a result, new vaccines have to be developed every year. In the case of a major epidemic or pandemic, the time it takes to produce an effective vaccine may cost lives. In the past, antibodies have been identified that target a broad range of Group 1 and Group 2 influenza A viruses, but not both.
The researchers at the UK's Medical Research Council (MRC) working with colleagues in Switzerland found the antibody, FI6, was effective at preventing and treating flu in mice and ferrets. Antonio Lanzavecchia, who led the study published in Science Express, said, “I would expect it to work very well in humans.” Other approaches to developing a universal vaccine that did not rely on antibodies were unlikely to work. “Antibodies are the key,” he said.
According to Sir John Skehel of the MRC the antibody could also be used as a treatment in conjunction with Tamiflu, the drug that reduces the severity of flu. The treatment would be reserved for hospitalized patients but it might have the potential to save lives and reduce demand for intensive care. He added, “The problem with Tamiflu is that you can get resistance. If you use them together [with the antibody] you could reduce resistance. Even though the 2009 flu pandemic was mild, intensive care units (ITU) across the UK were full. Caring for patients in ITU is hugely expensive – if you could reduce the pressure on intensive care that would be a real plus.” He said a single antibody provided a “clear advantage” in terms of developing a universal vaccine against influenza A because it was possible to identify the site on the virus where the antibody bonded.
Researchers at Oxford University announced earlier this year that they had tested a universal flu vaccine on human volunteers but that employed a different mechanism which involved increasing the body's T-cells to boost the immune response.
Steve Gamblin, from the National Institute for Medical Research, said of the latest study, “Historically, it has been impossible to predict precisely what kind of flu could develop into an epidemic and, as such, it has been necessary to develop new vaccines each year to tackle the different viruses. Our discovery may eventually help to develop a universal vaccine.”
In the longer term, scientists hope to create a vaccine that makes the body launch its own devastating attack on influenza by producing a surge of super-antibodies. The super-antibody is different because it latches on to a part of the stem of the haemagglutinin that is shared by all influenza A strains and appears not to mutate. Lanzavecchia calls it the virus's “Achilles heel”.