Vaccine production: a billion chicken eggs

How the H1N1 vaccine is made

Excerpt:

The most striking feature of the H1N1 flu vaccine manufacturing process is the 1,200,000,000 chicken eggs required to make the 3 billion doses of vaccine that may be required worldwide. There are entire chicken farms in the US and around the world dedicated to producing eggs for the purpose of incubating influenza viruses for use in vaccines. No wonder it takes six months from start to finish. But we'll get to that in a minute.

The most commonly used process for manufacturing an influenza vaccine was developed in the 1940s -- one of its co-inventors was Jonas Salk, who would go on to develop the polio vaccine -- and has remained basically unchanged since then. The process is coordinated by the World Health Organization and begins with the detection of a new virus (or rather one that differs significantly from those already going around); in this instance, the Pandemic H1N1/09 virus. Once the pandemic strain has been identified and isolated, it is mixed with a standard laboratory virus through a technique called genetic reassortment, the purpose of which is to create a hybrid virus (also called the "reference virus strain") with the pandemic strain's surface antigens and the lab strain's core components (which allows the virus to grow really well in chicken eggs). Then the hybrid is tested to make sure that it grows well, is safe, and produces the proper antigen response. This takes about six to nine weeks.

Comment: Still awaiting the opportunity to have the shot!