Fluenz is a vaccine. Vaccines work by ?teaching? the immune system (the body?s natural defences) how to defend itself against a disease. Fluenz contains strains of flu virus that have first been weakened so that they do not cause disease.
When a person is given the vaccine, the immune system recognises the virus as ?foreign? and makes defences against it. The immune system will then be able to respond more quickly when it is exposed to the virus again. This will help to protect against the disease caused by the virus.
Each year, the World Health Organization (WHO) makes recommendations on which flu strains should be included in vaccines for the upcoming flu season. These virus strains need to be included in Fluenz before it can be used. Fluenz will be updated with weakened virus strains type A-H1N1, type A-H3N2 and type B for each season, according to recommendations for the northern hemisphere from the WHO and from the European Union.
The viruses used in Fluenz are grown in hens? eggs.