Vaccine- All or part of a virus that elicits an immune response

When it comes to the creating vaccines, after the discovery of the influenza virus growing inside of an egg in 1931, the United States military began utilizing this method to make

vaccinations for the soldiers in World War II. Flu was a major concern for the United States Armed Forces as not long before, in World War One, an outbreak of what would become known as the 1918 Flu Pandemic killed upwards of an estimated 50 million people worldwide and no less than 675,000 Americans. One of the contributors to the discovery of this vaccine method, Jonas Salk, later was instrumental in the

development of the polio vaccine.

An embryonated egg is an excellent medium in which the influenza virus can grow. A small chip or incision is placed along the shell of the egg. At this point, a culture of the virus is placed, via syringe, in a specific location of the egg most suitable to the virus’ growth. In this case, that location is allantois. Experiments have been done to determine if multiple doses can be created from a divided allantois, however, the study indicated that an entire allantois was the most suitable host.

The allantois is a fluid filled sac with accessory blood vessels. These blood vessels are utilized by a developing chicken embryo for oxygen and gas exchange within the egg. The allantois also contains

metabolic wastes for the cell. These conditions  provide an excellent environment for the virus to grow.

Once the incubation is complete, the virus is extracted and purified. At this point, a single dose of flu vaccine has been created. Immunologists are presently exploring more efficient methods of culturing this vaccine.

The figure below indicates where in the egg various vaccines are cultured.

For more information on how the egg is used, the chicken, or how the phylogeny breaks down, follow the links below!

Home     The Chicken   Phylogeny   The Egg  About Me