Flu vaccine

From ArticleWorld

The flu vaccine is usually a combination of several strains of killed influenza viral particles that are designed each year to prevent as many possible cases of influenza during each “flu season”.

Manufacture and distribution

Each year, based on influenza strains occurring most commonly in other parts of the world, a selection of the strains felt to be most likely to occur in the U.S. and in Europe is made. In the 2005-06 winter influenza season, influenza strains H3N2, H1N1 and B-type were chosen as the dominant strains. It takes about 6 months to produce enough flu vaccine to protect those most likely to suffer complications from the flu.

Often, flu shots are recommended for the elderly, the Immunocompromised, some children and healthcare workers. Healthcare workers, while not necessarily high risk, can pass the infection on to the sick patients they care for. When influenza vaccines are plentiful, it is recommended that everyone get one. During shortages, only the elderly, healthcare workers and the very high risk should receive a vaccine.

The manufacturer grows injected flu virus inside fertilized chicken eggs and extracts the viral particles. The particles are then killed, mixed with killed viral particles from other viral strains, and are provided in a solution appropriate for injection. Sometimes a live attenuated (modified) vaccine is given as a nasal spray.

In some cases, a cell culture-based manufacturing technology can be used to make influenza vaccine, similar to the way some other vaccines are developed. One group of researchers in Pittsburgh developed a genetically-engineered viral vaccine that could be made in a month’s time. The reason behind the need for faster and faster manufacturing techniques is the potential for a worldwide pandemic of avian flu.

Specific vaccinations

There is a push to create a vaccine for the H5N1 strain of influenza, also called the avian flu virus. Unfortunately, the virus mutates frequently so that, when an epidemic of avian flu breaks out that can be spread from human to human, there may not be enough time to make enough vaccine to protect individuals from contracting it. Many specialists believe that such an epidemic is inevitable in the near future and that it will kill many individuals. The 1918 influenza pandemic that killed millions of people worldwide was a strain of the H5N1 avian flu.