There’s a lot of nonsense talked about flu. It’s serious. It kills directly, it kills indirectly and some strains can be lethal. Avian strains are tough for humans to catch but are very serious when we do; since 2003, the H5N1 influenza virus (commonly known as bird flu) has infected more than 650 people with a 60% mortality rate as well as being responsible for the deaths of millions of chickens and ducks. We are fortunate that this virus hasn’t yet achieved human-to-human transmission but a small number of mutations could change that, resulting in a pandemic.
But hope may be at hand. A team of investigators from St. Jude Children’s Research Hospital, Stanford University Medical Center, and MacroGenics have developed an antibody which has proven 100% protective against the virus in two species of animal models. The research is published ahead of print February 11, in the Journal of Virology, a publication of the American Society for Microbiology.
Antivirals have been potential sources of protection, but they are hampered by the propensity of viruses to rapidly mutate, which often results in resistance. Vaccines must be developed to match each flu virus strain and because they mutate so rapidly the vaccine is never fully protective.
In this study the investigators turned to antibodies, which target antigens on viruses as specifically as keys to locks, thus disabling them. But mutations can also render antibodies ineffective but in this case the researchers used a couple of neat immunological tricks which should make it much harder for resistance to emerge. The new compound is called FcDART, for Fc (the type of fusion protein) Dual-Affinity ReTargeting molecule. A single, low dose of the FcDART provided complete protection against lethal H5N1 viruses in laboratory models of influenza and could be given a day before infection — for example, to protect healthcare providers — or up to three days after.
Animal models are never perfect and while the search for a vaccine that works on all flu strains continues this is encouraging news.
Want to know more? We have a brilliant flu poster – contact us for a free copy – and you can read more on current flu research on our chief scientist’s blog. He also took on the British Medical Journal over their claims Tamiflu was a ‘waste of money’. It didn’t end well…