Actions included the closing down of schools, workplaces and most public places in Mexico for five days, and the closing of 430 schools affecting 245,000 children in 18 states in the U.S.

By the end of last week, however, the fears that this was the start of a global pandemic that would cause many thousands or even millions of lives had abated, mainly due to the mildness of the sickness in most of the confirmed cases.

The director of the WHO’s London-based World Influenza Centre, Alan Hay, said there are signs the virus is not as virulent as first feared, and it might not be more virulent than normal seasonal flu infections, according to an article in the Sunday Times of London.

The article adds that experts believe it may be comparable to seasonal flu, which kills up to 550,000 worldwide, and that initial analyses of the DNA sequence of the virus show it is more similar to the seasonal flu virus, and lacks the traits of the 1918 Spanish flu that killed nearly 50 million.   

Events this week should show whether this strain of flu will prove to be a dangerous pandemic, or will be only a mild form of flu.   Even if it turns out to be the latter, it was wiser to have been warned and to be prepared.

There are types of influenza that are easily spread because they are human-to-human transmitted but which are mild (like seasonal flu), and types that are deadly but not so easily spread (like the avian flu that has recently mainly affected Asia).

The real threat will come when an influenza virus mutates to become a deadly form which is also human-to-human transmitted and spreads easily.

The swine flu outbreak also served as a reminder that if a deadly pandemic were to develop, there will be a desperate fight over limited supplies of vaccines, in which the developing countries will be at a vast disadvantage.

This is because vaccines can be made to protect against a new and particular strain of flu only after this new strain appears, because parts of the virus are required to make an effective vaccine to counter that particular virus.

There is limited capacity to manufacture the vaccine. The present global manufacturing capacity is estimated at making 400 million doses of seasonal flu vaccines a year.

If there is a worldwide pandemic of a new deadly influenza, billions of doses of vaccines will be required, but there are vaccine manufacturers in only a few developed countries, and they will be able to supply only a small portion of what is needed.

Catalysed by the case of the deadly avian flu, developing countries led by Indonesia, Brazil and India have been fighting for reforms in the WHO influenza system so that developing countries (many of which contribute their viruses for research and for manufacturing vaccines) will be assured of a fair share of the vaccines that are to be made globally, and at an affordable price, when pandemics break out.

Without a system of fair benefit-sharing in place, developing countries will likely be left without vaccines, since the companies making them are located in developed countries which would want to ensure the scarce supplies are given to their own people first.

The best solution is to help developing countries develop their own capacity to manufacture the vaccines, so that enough can be available for all that require them when there is an outbreak.  This is an urgent matter as millions of lives are at stake.