An experimental flu vaccine made in insect cells not in eggs, where flu vaccines currently available in the United States are grown is safe and as effective as conventional vaccines in protecting people against the flu, according to results published in the April 11 issue of the Journal of the American Medical Association.
Removing eggs from the flu vaccine manufacturing process is one option for health officials seeking to protect the population from seasonal flu as well as a potential bird-flu pandemic. Using eggs to grow vaccine takes time; a flu vaccine that relies on a different technology is capable of being produced in large amounts much more quickly, a key advantage if a bird flu pandemic were to occur.
Eggs can be very cumbersome to work with, said John Treanor, M.D., the flu expert at the University of Rochester Medical Center who led the study of 460 people reported in JAMA. When you need hundreds of millions of fertilized eggs, youre dealing with a whole host of agricultural issues, as well as scientific concerns regarding the flu virus itself. Flu viruses can be temperamental, and its not always an easy matter to get the virus to grow as you want in eggs.
The use of cell culture systems to grow vaccines using viruses as tiny factories to churn out mass amounts of vaccines is a growing business. A similar technology using human cell lines is used to produce the hepatitis B vaccine, while one form of a vaccine against human papilloma virus is made using the same insect cell line used in the JAMA study.
In the study conducted by Treanor, together with colleagues at Cincinnati Childrens Hospital and the University of Virginia, scientists tested a vaccine called FluBlOk that is made by Protein Sciences Corp. of Meriden, Ct. FluBlOk relies on a virus known as baculovirus, which normally infects insects, to churn out the key components of the flu virus in a cell line drawn from caterpillars.