Influenza pandemics are to be expected. They develop from either bird or pig influenza viruses. It is impossible to predict which strain will cause the next pandemic or epidemic. This leaves scientists playing the odds when choosing the viruses for the yearly vaccines.
Pandemic Influenza Viruses
There are three types of flu viruses: Influenza A, Influenza B and Influenza C. Influenza A causes human flu pandemics. Influenza A viruses are further subdivided depending on two of their surface proteins; hemagglutinin (H) or neurmindase (N). There are 16 known H proteins and 9 N proteins; the virus exists as a combination of the two proteins. For example the infamous pandemic Spanish Flu of 1918 which killed 40 million people worldwide is attributed to the H1N1 subtype. The H1N1 Influenza subtype is also responsible for the current swine flu of the spring of 2009 (Kansas State University. "1918 Flu Resulted In Current Lineage Of H1N1 Swine Influenza Viruses." ScienceDaily 1 May 2009, retrieved 2 May 2009).
Using Influenza Vaccinations to Prevent Flu Outbreaks
Flu vaccines which are composed of a weakened or dead virus are effective when taken before a viral infection occurs. Once the vaccine enters the body, the immune system creates antibodies against the surface proteins of the vaccine’s virus, readying the body for future infections. However, the vaccine is only effective if the vaccinated individual is exposed to the subtype of influenza virus contained within the vaccine. With the flu viruses rapidly mutating, predicting which influenza virus to use in the vaccine is tricky. Scientists can only use past data and statistics in an attempt to predict which virus will be prevalent during the flu season.
A Universal Flu Vaccine May Protect Against Different Influenza Subtypes
Instead of weakened or dead influenza viruses, researchers are turning to the proteins contained within the influenza viruses to create vaccines. An example of a universal flu vaccine is the Bivalent Influenza Peptide Conjugate Vaccine (BIPCV). This vaccine has been tested in a Phase I clinical study that used 370 healthy study participants. The results of the study show promise (World Health Organization, Initiative of Vaccine Research “Pandemic Influenza Vaccine Clinical Trial Abstract Minimum information.” WHO Retrieved 2 May 2009). BIPCV is not the only Universal Flu vaccination being tested. According to Acambis, a biotech company based in the UK, the clinical trials for ACAM-FLU-A are also yielding positive results. The vaccine is designed to protect against all Influenza A viruses (Acambis “Acambis reports positive data from trials of universal influenza A vaccine” Acambis Media Release 3 January 2008, retrieved 2 May 2009).
With advances in biotechnology, researchers are closing in on developing universal influenza vaccines that will be able to protect the population against unforeseen outbreaks of influenza. By focusing on other aspects of the virus, besides its surface proteins, researchers are able to find other vulnerable avenues to disable the virus. The good news is that the flu vaccinations efficacy will no longer be left up to chance and that scientists will no longer have to update the flu vaccine yearly. This will lead to a better supply of flu vaccines and a better protected population reducing the risk of Influenza Pandemics.
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