[The quality standardization of a national vaccine against yellow fever]

One of the commercial lots of yellow fever vaccine has been attested as the National Branch Standard (NBS) of yellow fever vaccine. This NBS has been studied in all tests required by the regulations for standard vaccines. The NBS has been found to meet the necessary requirements in all its characteristics. The study of the thermostability of the NBS at temperatures of 4-10 degrees C, 20-22 degrees C, 37 degrees C during storage for 24 hours to 1 year has revealed the rapid loss of the infectious capacity of the virus at the above temperatures and its high stability during storage at -20 degrees C. Thus, the NBS has been found to retain the required level of immunizing potency for 3 months at a temperature of 4-10 degrees C, for 1 month at 20-22 degrees C and for 2 weeks (the term of observation) at 37 degrees C. The heat resistance of the NBS of yellow fever vaccine corresponds to the WHO requirements. The newly developed NBS has been used as the standard preparation for controlling 27 lots of commercial yellow fever vaccine.