Stability of vaccines against Marek's disease
Ingwersen, P.; Kraft, V.; Monreal, G.
Deutsche Tierärztliche Wochenschrift 81(13): 302-304
1974
ISSN/ISBN: 0341-6593 PMID: 4603842 Document Number: 76175
Samples of different German commercial MD vaccines were tested after storage at various temperatures. A plaque technique using a solid agar overlay medium (see V.B. 43, abst. 5727) was used to estimate loss of infectivity. A vaccine suspension with SPGA showed an 85% fall in virus titre after storage for two hrs at 29 deg C, but, after two hrs at 4 deg C, only a 20% fall. Freeze-dried vaccines, not resuspended, showed up to 50% reduction in titre within 4 days at 24 deg C, with slower reduction up to 18 days. Stored at 38 deg C, 60-80% of the infectivity of freeze-dried vaccine was lost after four days.