A study of new vaccines for forest encephalitis, initiated by the China Ministry of Science and Technology and implemented by the Changchun Institute of Bioproducts, has been granted with a national certificate for new drugs and the associated approval for production. Combining cell based virus culture technology and modern biotechniques, including consecutive centrifugal technique, highly filtered concentration, and chromatography, the study increases the antigen concentration in the vaccine by eliminating most unwanted chemicals, such as proteins and formaldehyde. The new vaccine registers an immune protection index ?Y5.0?á105, or five times higher than the one produced by conventional technology. Clinical trials show that positive turning rate of antibody in volunteers?¯ blood samples exceeds 85%, with an enhancement of 70% or more, compared to conventional technology. The new vaccine has so far reported no adverse effect through the body, though with a 0.87% for local adverse effect. The vaccine has been confirmed for its fine security and immune effects.

To meet the market needs, the Institute is currently working on mass production of the new vaccine, in a move to replace grossly prepared vaccines, and to provide an enhanced means to prevent forest encephalitis.