Hendriksen CFM ,
Woltjes J ,
Gun JW van de ,
Akkermans AM ,
Marsman JW ,
Verschure MH ,
Veldman K
41 p
in Dutch
1993
Toon Nederlands
English Abstract According to the specifications of the European
Pharmacopoeia (EP) monograph on Tetanus vaccine for veterinary use (EP 1990)
potency testing is based either on immunization and bleeding of guinea-pigs
or rabbits, followed by estimation of the antitoxin titre by toxin
neutralization assay (TN test) in mice (Method A) or on immunization and
challenge of mice (Method B). Recently in vitro serological assay systems
have been described as potential alternatives to the TN test. These include
Enzyme Linked Immunosorbent Assay (ELISA), Toxin Binding Inhibition (ToBI)
test, Haemagglutination (HA) test and modifications of these procedures such
as antigen capture ELISA and antigen competition ELISA. An interlaboratory
validation study was initiated to evaluate the suitability of the in vitro
serological methods to provide valid and reproducible measurements of the
biological potency by Method A of the EP. This report presents the results
of this study. Intra- and interlaboratory variation was acceptable for
ELISA and ToBI test, but large variation was seen in the HA test. Estimates
of potency obtained by TN test and by in vitro test systems were in good
agreement for a wide range of products and a wide range of antitoxin titres.
It is concluded that the TN test for the estimation of potency of tetanus
toxoid vaccines for veterinary use according to Method A of the EP can be
replaced by ELISA or ToBI test. Standardization of HA test is required
before this test can be used for quality control
purposes.
