The bird flu virus undergoes constant changes as it mutates genetically. This makes identification of one particular virus type as the culprit absolutely impossible. For the same reason any pharmaceutical preparation targeting one particular type of virus would be useless in case flu is caused by a changed virus derived from the old known one.

WHO leads a Global Influenza Surveillance Network with 110 influenza centers in 83 countries and four WHO Collaborating Centers. Representative samples of patients having bird flu like symptoms are collected and investigated for bird flu viruses. The latest strains circulating across the world are identified and recommendations are made about the flu vaccine's composition. This is done in February and September every year.

After the WHO gives guidelines for the strains to be put into the vaccine from the selection of the strains to be used in the vaccine, all the way to the final vaccine, is a lengthy process that may take up to 6-8 months. Production of the new vaccine strain starts immediately after the WHO announces the strains. The strains then undergo quality testing. Then only all the three different strains, two influenza A and one influenza B strain, are mixed into a single vaccine. It is now that the vaccine is packaged and shipped for sale and administration.

The bird flu vaccine has its own side effects too. Usually the injection site shows some redness and swelling; fever, vomiting, headache, sore throat and minute physical discomforts are also noticed in about 5% of the cases.

Currently the total production capacity of the world is about 300 million influenza vaccines per year. And the world population is about 6.5 billion! So it is quite apparent that in the case of a pandemic not everyone can be vaccinated unless we either stockpile vaccine or produce it at war footing; the former being not possible since the composition of vaccine keeps changing every year and would not be possible in the near future. For these reasons if a pandemic occurs, then for a few starting months we won't have bird flu vaccines at our disposal and our only saving grace would be non-medicinal measures.

Even for the amount of vaccine that is available, it would need the world's healthcare system to have a well defined distribution plan and an extremely reliable supply chain system, in order to cope with demands. Such level of distribution and administration of the vaccines is simply not feasible today.

It is clear by now that the stock of vaccines produced every year gets wasted if the flu virus changes, which it does from year to year. But still these drugs are manufactured so as to test and demonstrate the technological capability of the system which is in place. WHO reports that the usage of antiviral drugs and vaccination are the most effective measures against a bird flu threat. But then again it is quite evident that only the vaccination cannot help the 6.5 billion population of earth. It is just one of the desperate measures we can rely upon. Alongside we will have to keep upgrading public knowledge about the preventive measures, keep taking all the precautions to curtail the spread of influenza and keep researching for better ways to fight the virus.