Dan Boyle
Question:144 Mr. Boyle asked the Minister for Health and Children the percentage of strains of the flu virus the vaccine will counteract; and if he will make a statement on the matter. [27591/03]
Written Answers. - Vaccination Programme.
The best public health measure to prevent influenza is the use of inactivated influenza vaccines. The strains of the influenza virus are subject to constant change, and that is closely monitored by the World Health Organisation, or WHO, and other health organisations around the world. The vaccine is prepared each year using virus strains similar to those considered most likely to be circulating in the forthcoming season.
On 28 February 2003, the WHO published a recommendation on the composition of influenza vaccines for use in the 2003-2004 northern hemisphere influenza season. Current vaccines are trivalent, containing antigens from two type-A and one type-B virus strains. Each year the WHO advises on the composition of the vaccine for the influenza season.
The recommendation was as follows: A/new Caledonia/20/99(H1N1)-like virus; A/Moscow/ 10/99(H3N2)-like virus – the widely used vaccine strain is A/Panama/2007/99; B/Hong Kong/330/2001-like virus – currently used vaccine strains include B/Shandong/7/97, B/Hong Kong/330/2001, B/Hong Kong/1434/2002.
Laboratory testing so far this year shows that the main strain circulating is influenza A (H3N2), a Fujian-like strain. That is slightly different from the A (H3N2) Panama-like virus, which has been circulating in Europe in recent years. The current flu vaccine contains the Panama-like virus and is considered to offer some protection against the Fujian-like strain and good protection against other strains that may also circulate.
The impact of the influenza vaccine in reducing mortality from influenza in older people is well documented. Protection lasts about one year and, therefore, it is important that individuals who are at risk of contracting influenza be vaccinated annually against the current strains.
Question No. 145 answered with Question No. 98.