Researchers at Harvard believe that they may have found a novel approach to battle influenza, the virus that causes both swine and avian flu, as reported in the New York Times.

Swine flu is caused by the influenza A virus H1N1 (avian flu is caused by the same family of virus, but is of a different subtype, H5N1) with the H and N referring to the surface proteins hemagglutinin and neuraminidase, respectively. Both proteins reside on the surface of the virus and serve specific functions for it’s survival and propagation.

Antiviral therapy against flu include oseltamivir (Tamiflu) and zanamivir (Releva), which are neuraminidase inhibitors. They act on the neuraminidase protein and block the virus from leaving the cell and spreading.

The ideal situation, however, would be to have a vaccine that could be administered proactively before the outbreak of the disease. The current flu vaccine is based, like virtually all vaccines, on the concept of recognition. By exposing our bodies to an killed or weakened form of the virus, our immune systems are primed and ready when the actual exposure occurs.

This recognition is based on what the body can first “see” once we are exposed to the invaders. Unfortunately, there are two primary species of the flu virus (influenza A & B) to contend with, and within influenza A (which impacts humans the most), there are several different sub-types based on the variability in the hemagglutinin (H) and neuraminidase (N). To date, there are sixteen different known types of hemagglutinin alone (H1-H16).

All this variability makes the decision on how to vaccinate the public a bit of a guessing game. Not only must they decide which species will appear (A or B?), but they must also try to determine which sub-type within the influenza A species it will be. Consequently, the actual vaccine, which must be changed every year, is a mixture that represents the best estimate of what might appear come flu season.

To complicate this matter further, the exposed region of the hemagglutinin surface proteins that is most readily visible to our immune system (think of it as a lollipop with the exposed region being the head) mutates constantly, so by the time a vaccine is chosen and distributed, the virus could have changed enough to render it ineffective.

Now, however, they may have developed a novel way to address these complications. It turns out that the while the tip of the hemagglutinin protein goes through a great deal of mutation, there is a sequestered region near the base that does not (the handle of the lollipop). Because this area is conserved, targeting it gets around the problem of mutation.

By exposing the base of the protein and then binding it with an engineered antibody (a protein that attaches to viral surface markers), the virus was able to enter the cell but incapable of reproducing. In fact, the antibody therapy proved effective against both the H1 and H5 subtypes and provided protection against the flu in 80% of the cases using animal models.

The approach is not without its limitations, however. There is, of course, the problem of exposing the “handle of the lollipop.” Furthermore, because the flu is so variable, there are other strains and subtypes to consider, including H3 and B, so a vaccine is still in the works. As a therapy, however, the researchers say the treatment is ready to go, though further testing for safety and efficacy in humans by the FDA will be needed.

Even still, the results represent a promising step in the right direction, and with the current swine flu outbreak reaching a pandemic level, timing is of the essence. With the influenza tied to an estimated 36,000 deaths per year, and the growing concern over a global pandemic of avian flu, the public health implications are enormous.

If you have questions or concerns about swine flu, check out the CDC website for more information. If you feel you may have been exposed to swine flu, consult your physician and find out what your treatment options are. In most cases in this country, the symptoms thus far have been manageable and treatable with oseltamivir or zanamivir.