Because it is so common perhaps, many people do not consider the flu serious. However, it kills about 40,000 people in the US every year. Although it is clear an individual can be effectively vaccinated for a specific influenza virus, general flu vaccinations have had little impact stemming seasonal flu outbreaks. This ineffectiveness comes about because are so many variations of the influenza virus.
In humans, it is almost always the influenza virus type A or type B that cause the flu. However, there are hundreds of strains of each of these types, and new mutations of both types occur every year. Influenza type A, in particular, mutates very often.
Vaccines work by mimicking the virus to trigger an immune response in the body. This mimicry is done using a severely weakened version of the virus, or even just a part of the virus like one of the proteins on its outer surface. The response to the vaccine causes the body to make antibodies that are later ready to attack the real virus should an actual infection occur. However, the plethora of influenza virus variations create a problem. Each year, scientists try to predict which viral influenza variants will be the most prevalent and they make a vaccine targeting the top three. Often they bet wrong.
To solve this influenza variance problem, researchers at the Scripps Research Institute in San Diego, in collaboration with the Dutch company Crucell, have been trying to find a few antibodies that can target and inactivate the bulk of influenza viruses. They hope to use this information to develop a universal flu vaccine.
These researchers have been screening flu antibodies from the immune cells of volunteers to find ones that recognize several versions of the virus. A few days ago this group published an article indicating they found antibodies that target three functionally important sites present on most influenza B viruses. This work follows up their previous publication almost exactly one year ago where they found antibodies that target two important sites generally found on all influenza type A viruses. In both cases, the antibodies they found appear to neutralize most all variants of type A or type B influenza in mice.
An actual vaccine is still a ways off of course. As noted above, vaccines work by using the flu virus to get the body to make its own antibodies against the virus before infection. The information from the studies does not enable scientists to directly make a traditional flu vaccine using the antibodies. However, it does provide information that could enable engineering of a vaccine that induces an individual's body to make these antibodies. Also, it may be possible to create an anti-flu drug to treat influenza infection by producing derivatives of these antibodies in large quantities. Either way, it's a big step forward toward a better flu treatment.
You can read more about this recent publication in the Scripps News Release.