About 200 million influenza vaccine doses are produced and given globally every year, saving hundreds of thousands of lives and reducing illness in the most vulnerable: the elderly and people with underlying chronic disease.

The annual decision about the vaccine composition is made possible by the co-ordinated work of more than 110 influenza laboratories and four WHO Collaborating Centres.

WHO experts recommended that the influenza vaccine for 2002 in the Southern Hemisphere contain the following three components:

• an A/Moscow/10/99(H3N2)-like virus
• an A/New Caledonia/20/99(H1N1)-like virus
• a B/Sichuan/379/99-like virus

This vaccine is intended for use from May to October 2002, the Southern Hemisphere influenza season. The timing of this WHO recommendation is critical to allow sufficient time for companies to produce a novel vaccine before the next influenza season starts.

Based on the WHO recommendation, national authorities should approve the specific vaccine viruses and national public health authorities are responsible for recommendations regarding the use of vaccines.

WHO URGES VACCINATION FOR NORTHERN HEMISPHERE

The influenza season in the Northern Hemisphere will soon start and it is time for vaccination.

Many countries have already begun advertising for vaccination campaigns focusing on high risk groups (people 65 years or older; adults and children aged six months or older with chronic illnesses or who are immuno-compromised). For instance, the United Kingdom aims at 65% coverage in those age groups and has embarked on a national immunization programme. The province of Ontario in Canada has gone one step further: aiming at universal coverage, it will give free vaccine to all its citizens who wish to be protected against influenza.

The "flu" has been estimated to infect as many as 100 million people each year in the Northern Hemisphere. While most healthy people fully recover from the flu, the disease can result in hospitalization or even death.

WHO, therefore, strongly recommends vaccination against influenza, the most important measure against the disease, particularly among those at high risk of developing complications.