“When we think of the major threats to our national security, the first to come to mind are nuclear proliferation, rogue states and global terrorism. But another kind of threat lurks beyond our shores, one from nature, not humans – an avian flu pandemic.” – Barack Obama, June 2005

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I remain a proponent of vaccination irrespective of the controversies that keep coming up. I think anybody who has seen a child with a tetanus infection will be. India continues to have killer infectious diseases and though I admit that there is a need for the health ministry to delve into the storage and administration of vaccines with a little more vigilance I cannot agree with withholding any of the mandatory vaccines. The Indian Academy of Paediatrics makes recommendations only after a review of current published literature on various parameters that include need for the vaccine, its efficacy and safety. Having said that I do acknowledge that there are contentious issues involved – we cannot inject a plethora of microorganisms and chemicals into the bodies of our young children without considering the strain on their immune systems. Therefore, while certain vaccines are imperative, others can be administered as per the physician’s recommendation.

The vaccination for influenza falls into the second category. Flu is a seasonal occurrence and yet pandemics occur because a virus emerges and starts spreading easily because we have no pre-existing immunity. This is one characteristic of the flu virus, which mutates rapidly into new forms. So we have H1N1, H3N2 and so on. Sometimes two flu viruses can attack the same animal and their proteins get mixed up and re-assorted  to form new forms. That is why we can never predict what the next pandemic will bring forth-a benign selection or a lethal one. Once a fully contagious virus emerges, its global spread is inevitable. Countries might, through measures such as border closures and travel restrictions, delay arrival of the virus, but they cannot stop it.

A flu vaccine takes two weeks to produce an effective protective response in the body.  Protection decreases by about 50% over the next six months (the decrease is less for older adults), and remains stable for two to three years. Antibodies made by the immune system in response to vaccination with one strain of influenza viruses can provide protection against different, but related strains. But eradicating flu altogether is not possible.