After it was first confirmed in Mexico in April this summer, H1N1 - popularly referred to as swine flu -- ruled headlines and urban consciousness for the next four months. The media frenzy has died down, but has the flu? Dr Salim J. Habayeb, WHO Representative to India, updates HT on whether we still need to worry about H1N1. Watch video

Q: Is the worst of the pandemic over or does the threat of a more deadly
strain still exist?
First, let me put this disclaimer:  influenza viruses are difficult to predict. More so, when we are dealing with a novel strain.  Influenza viruses constantly change as they replicate and this is their hallmark.

All things considered, it is my personal view that the pandemic is not over. The bulk of the global population is still susceptible. At present, we are witnessing a pandemic that continues to simmer with regional exacerbations. There is exacerbation in the US, continued transmission in Mexico and Europe, and a mixed situation in South Asia.

So we should brace ourselves for more "next waves". The good news is that the pandemic caused by this specific viral strain would subside when widespread immunity is generated through natural infections and vaccinations.

Q: Is screening at airports necessary? What is your view?
Our official WHO position is not to recommend travel restrictions under existing circumstances for pandemic H1N1 2009. But many countries did institute cross-border measures based on past deliberations.

Such travel measures may possibly be useful in the early stages, what we call the containment stage.  But at the pandemic phase 6, such containment measures are of limited value since the infection is disseminated and spreading at the community level.  At this point in time, attention should focus on care for the sick, while concurrently using vaccines.

Q: Why is it taking India longer than the West to develop indigenous vaccines?
The countries that have developed H1N1 vaccine had the production track ready. If I grossly oversimplify, they had only to introduce a new strain.  It's like changing an ingredient in an ongoing process. This strain change is anyway made each year with seasonal vaccine. In this context, such vaccines are not entirely "new" vaccines. They build on the technology already used to produce vaccines for seasonal influenza, and benefit from already established procedures for testing and regulatory control.

In India, since we did not have production of seasonal influenza vaccines, the whole cycle had to be developed from scratch.

Q: What are the lessons learned from the H1N1 pandemic?
Globally, the world has realised the importance of providing timely and relevant information to the population. Public understanding and cooperation are key ingredients to effective responses.