New generation of cell culture assay for smallpox vaccine potency.
The potency of smallpox vaccines produced in the 1970s was tested by titration onto chorioallantoic membranes of fertilized hen eggs (CAM assay). The potency specification commonly approved for these vaccines was a titer above 10(8) pock-forming units per milliliter. We developed and validated a cell culture titration assay to have a more reliable potency test. The cell titration assay and the CAM assay were tested in parallel on 34 first-generation smallpox vaccine lots. These allowed us to demonstrate that a correlation does exist between the two titration techniques and to determine a new in-house specification for the cell titration method. This in vitro potency assay will allow us to test first-generation smallpox vaccines produced on the skin of living animals but will also give a hint of the potency specification that should be assigned for new generations of cell-derived smallpox vaccines.
Leparc-Goffart
Isabelle
I
Agence Française de Sécurité Sanitaire des Produits de Santé, 69007 Lyon, France. Isabelle.Leparc-Goffart@afssaps.sante.fr
Poirier
Bertrand
B
El Zaouk
Annie
A
Tissier
Marie-Hélène
MH
Fuchs
Florence
F
D000482:Allantois / Q000187:drug effects; D000818:Animals; D018929:Cell Culture Techniques / Q000379:methods*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002642:Chick Embryo / Q000187:drug effects; D002823:Chorion / Q000187:drug effects; D005612:Freeze Drying; D012900:Smallpox Vaccine / Q000032:analysis* / Q000592:standards / Q000633:toxicity
D012900:Smallpox Vaccine