Standardization of a neutralizing anti-vaccinia antibodies titration method: an essential step for titration of vaccinia immunoglobulins and smallpox vaccines evaluation.
The possibility of mass population vaccination with smallpox vaccine implies the development of anti-vaccinia immunoglobulins for the treatment of severe side effects following vaccination. We have chosen to develop and validate the "gold standard method" (plaque reduction neutralization assay) to titrate neutralizing anti-vaccinia antibodies in two different French laboratories belonging to the Department of Defense (CRSSA) and to the French Health Products Safety Agency (Afssaps). The results of precision, linearity and accuracy of the method led to consider the method as validated. In parallel, we have prepared and lyophilized a pool of anti-vaccinia plasma samples issued from a unique donor and qualified this preparation versus the first British standard to use it as an in-house standard with a titer of 25 international units (IU). This work will allow to titrate, in IU, sera from vaccinated persons in order (i) to titrate purified anti-vaccinia immunoglobulin preparations for vaccine severe side effect treatments; (ii) to investigate the level of neutralizing antibodies in the general population; and (iii) to investigate clinical trials of new generation smallpox vaccines. In the future, this will allow comparability of studies on either smallpox vaccines or on the serological status of the population.
Leparc-Goffart
Isabelle
I
Agence Française de Sécurité Sanitaire des Produits de Santé (Afssaps), 69007 Lyon, France.
Poirier
Bertrand
B
Garin
Daniel
D
Tissier
Marie-Hélène
MH
Fuchs
Florence
F
Crance
Jean-Marc
JM
D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis / Q000097:blood; D002522:Chlorocebus aethiops; D005069:Evaluation Studies as Topic; D007136:Immunoglobulins / Q000032:analysis*; D009500:Neutralization Tests / Q000379:methods*; D012015:Reference Standards; D012900:Smallpox Vaccine / Q000032:analysis*; D014611:Vaccination; D014615:Vaccinia / Q000175:diagnosis / Q000276:immunology*; D014616:Vaccinia virus / Q000235:genetics / Q000276:immunology*; D014709:Vero Cells
D000914:Antibodies, Viral; D007136:Immunoglobulins; D012900:Smallpox Vaccine