The World Health Organization are considering to send a national report next month and advise the government to think about stockpiling vaccine against H5N1 because a possible global pandemic could begin at any time now.

WHO took this decision after realizing that H5N1 was not going to vanish over night from Asia, that increasing the risk of a further transmission of H5 N1, declared Klaus Stöhr, head of the WHO's influenza team.

The US has already ordered 4 million doses of the vaccine and France and Italy planned to stockpile two million doses. This quantity is not enough for everyone in case of a global pandemic, and not all countries afford to buy a lot of doses to cover up the population's need.

Scientists can not know which strain of the virus will attack next. It can be H7 or H9 and so, the scientists can not prepare a proper vaccine until the pandemic starts, this fact making the stockpiling possibly not necessary. Recent studies affirm that a stockpiled vaccine can be effective partially even though it is not made for the current strain of the virus.

Experiments made on animals at St Jude's Children's Hospital in Memphis, Tennessee, US, concluded that once infected with a strain in the past, you are protected from dying in case of another H5N1 infection.

People need two doses of H5 vaccine to produce the right immunization to neutralize the virus. After that, when meeting with a specific pandemic virus people will need only one shot of the vaccine.

A real problem is the mass producing of H5 vaccine and by now only half of the ordered doses by US were delivered by Sanofi Pasteur, a French company, the other half remaining to be made at a plot factory in Liverpool.

Another problem is finding out whether a vaccine will be effective on the next virus that will attack. Scientists can only adjust the dose that is needed to produce an immune response.

Clinical testes of batches of H5 vaccine will be carried out in US, Canada, Australia and Japan, sponsored by the governments. They will be tested separately because the vaccines have been produced in different factories and with different methods. Unfortunately, no European government wanted to fund the tests, even though Europe products most of the world's flu vaccines.

Some scientists, like Albert Osterhaus of Erasmus University in Rotterdam, consider that stockpiling antiviral drugs is better than stockpiling H5 vaccine. But it is hard too to prepare an anti-viral and there is not a certain fact that anti-viral drugs will work against a pandemic strain.