| 摘要 |
<p>An attenuated live measles virus vaccine is prepared by serially culturing a measles virus, that has been adapted to grow in living non-human cells, in a culture medium comprising living non-human animal cells at a temperature below 35 DEG C, but at a temperature higher than that at which propagation of the virus ceases. The temperature is preferably 28 to 32 DEG C, for part or whole of the cultivation steps. At least 40 serial passages are required. Avian particularly thick embryo tissue is preferred, but bovine kidney tissue may be used. The measles virus may be an adapted strain of the Edmonston strain of measles virus e.g. Enders strain. The strain employed may have been adapted to grow in living non-human cells by serial culture in (a) human e.g. amnion or heart tissue culture and then (b) animal tissue e.g. chick embryo tissue at conventional incubation temperatures e.g. 35 DEG C. The culture fluid may be Earle's basic salt solution containing 5% calf serum or 10% of horse or lamb serum and 0.5% lactalbumin hydrolipate; or medium 199 with 5 or 10% of horse serum. The separated virus may be stabilized with lactose glutamate solution and the final vaccine contains a parenterally acceptable diluent or is freeze-dried. Reference has been directed by the Comptroller to Specification 968,980.</p> |
