Every year the health care officials have to start over again the seasonal struggle to battle with flu. The problem with the flu vaccines currently available is that their effectiveness vary tremendously from year to year. The reasons for this is that there are three major types of the influenza virus called A, B and C. These viruses can further be subdivided, depending on the sprinkling of proteins decorating their surface, into many different strains and lineages.
Researchers are trying to design a flu vaccine that could work on all the known strains of the virus and its effects would be lifelong effective. Such a vaccine would allow the medical community to stop the next flu pandemic before it even starts.
Conventional flu vaccines available today target only the head of the hemagglutinin (HA) molecule that sticks out from the surface of flu viruses. These HA heads are unique to each flu strain and the vaccines need to be created for individually targeting a particular strain of the virus.
Every year, scientists need to make educated guesses months before flu season actually strikes, on which three to four strains of influenza virus they need to include in their vaccines. This decision is made by the CDC together with the World Health Organization and other health organizations. The decision relies heavily on epidemiological data from previous flu outbreaks, whom they infected, when and where they occurred, and what the outcome was.
This it's a risky proposition that can leave us unprepared for the flu season in case of the wrong guess. Fortunately, most of the time, the WHO gets lucky. But the guess may fail because the scientists are outmaneuvered by unpredictable HA mutations. These mutations may even happen after the vaccines have already been made.
In some of a terrifying nightmare scenarios such as the swine flu and bird flu, the influenza virus that can previously only infect other animals can "jump" suddenly to humans. Such epidemics may happen again without a universal flu vaccine on hand. A universal vaccine would be able to target any influenza virus regardless of whether or not it has previously seen before.
In studies published recently in Science and Nature Medicine, two separate research teams reported they found a new way to create new flu vaccines by targeting the stem, a relatively stable part of the HA molecule.
Dr. John Oxford, a flu expert at the University of London declared in an interview for BBC News that "broad spectrum" antibodies can neutralize multiple types of flu virus by latching on to the stem of the HA molecule and scientists can use this mechanism to engineer vaccines that can fight entire lineages of flu and even new emerging strains. This would be an important step forward compared with today's vaccines, according to the scientist.
