Show vaccines from eggs E hall half a million american hens are ar now laying eggs to be half hatched for conversion into vaccines to fight typhus and influenza owners of these specially selected birds get 15 cents a dozen more than for ordinary eggs because of numerous exacting requirements for instance only white eggs are used thus making detection of contaminating dirt on the shells easier also to promote essential cleanliness and reduce nest breakage eggs are collected oftener for shipment in trucks heated to maintain incubation temperature pera ture at the laboratory the embryo is needled with the virus in inoculation 0 cul aaion through an aperture in the air cell end of the egg the break in the shell is sealed and the egg returned to the incubator the virus multiplies and the desired antigen as well as we alie infectious material is produced in the embryo the infectious qualities are destroyed by chemical treatment before the vaccine is refined |