ABSTRACT
To optimize the thermostability of lyophilized 17D vaccine, the authors investigated parameters important for the freeze-drying process. Six different stabilizers with different sugars and amino acids were analysed in a freeze-thaw cycle for their crystallization characteristics and their stabilizing effect under thermal treatment conditions of 37 degrees C for 28 days. This test indicated that three out of six stabilizers (B, C, F) kept the vaccine significantly more stable than the three others (A, D, E). Under storing conditions of 4 degrees C over 96 days stabilizers A, B and C produced the lowest decrease in titre of about 10% in contrast to stabilizers D, E and F with a higher decrease in infectivity titre. Analysing the stability of the 17D vaccine using five different reconstitution solutions, we found that 90% D2O shows the best stabilizing effect under thermal treatment of 37 degrees C up to 24 h.
Subject(s)
Viral Vaccines , Yellow fever virus/immunology , Crystallization , Freezing , Solutions , TemperatureSubject(s)
Animal Feed/analysis , Daphnia/physiology , Animals , Fresh Water/analysis , Medicago sativa/analysis , Metals/analysis , TroutABSTRACT
Administration of 6-aminonicotinamide into eggs may interfere with the development of the chick embryo. The prevention of this effect by nicotinamide has been shown before. In the present study, it could be demonstrated that a combination of nicotinic and L-methionine may also produce this effect. If applied alone nicotinic acid exhibited low effectiveness and L-methionine none at all.
