Nov. 5 (UPI) -- A vaccine against the flu, derived from four llama antibodies and a harmless virus, showed promise to offer universal, long-lasting protection in a study with mice.
With 900,000 hospitalizations and 80,000 deaths from the the flu last year, the need for a universal flu vaccine is significant as most flu vaccines are designed to target a few strains and, if predictions are wrong, the vaccine will prevent fewer people from getting sick.
Currently, there is no universal flu vaccine on the market -- but that could change over the next decade, or less.
Antibody engineer Joost Kolkman at Janssen Infectious Diseases in Beerse, Belgium, and his colleagues determined this unusual class of antibodies made by llamas and their camel cousins protected against influenza A and B viruses, including avian-borne strains like H1N1.
Although their vaccine must go through more testing before human trials can begin, Janssen researchers hope theirs ultimately can become a universal vaccine against the highly mutable flu virus.
Members of the research team developed their vaccine by injecting llamas with a vaccine containing three different influenza viruses, as well as the viral surface protein, hemagglutinin, from two other flu strains.
"The rapid onset of protection, together with the unprecedented cross-reactivity of MD3606 to avian influenza strains, also offers the possibility of using this approach as a prophylactic immediately upon onset of an influenza pandemic, providing substantial advantages over vaccination," the authors wrote in findings published last week in the journal Science.
"Administered intranasally to mice with an adeno-associated virus vector, the antibodies provided durable and continuous protection from a panoply of influenza strains," the researchers wrote of the llama-derived vaccine candidate.
Researchers at the University of Pennsylania are also developing a vaccine with a strong antibody response to the hemagglutinin stalk. Like the Janssen researchers, their study was done with mice.
Unlike seasonal flu vaccines, a universal flu vaccine could be given a few times over a lifetime to provide protection potentially similar to a tetanus vaccine.
Researchers at the University of Nebraska, who are developing a vaccine from the centralized ancestral genes of four major influenza strains, say a universal vaccine may not be ready until 2020 or 2025, but theirs is only one of several that hold promise.
In February, the National Institute of Allergy and Infectious Diseases launched a Universal Influenza Vaccine Strategic Plan "to simultaneously broaden knowledge around basic influenza immunity and advance translational research efforts to drive universal influenza vaccine development."
The agency says a universal flu vaccine should be at least 75 percent effective, protect against group I and II influenza A viruses, protect at least one year and be suitable for all age groups.
One experimental vaccine, M-001, is headed into phase II clinical trials among 120 healthy volunteers. Six previous clinical trials involving 698 participants conducted by BiondVax in Israel and Europe indicated that the vaccine candidate was safe, well-tolerated and produced an immune response to a broad range of influenza strains.