Mouse protection test as a predictor of the protective capacity of synthetic foot-and-mouth disease vaccines.
A passive immunity test (MPT) in suckling mice for the quantification of protective anti-foot-and-mouth disease virus (FMDV) antibodies in serum is described. Comparisons with titres obtained using conventional serum neutralization tests show that for cattle given synthetic peptide vaccines this in vivo assay is a better indicator of protection, while for convalescent animals and virus-vaccinates both tests are equally valid predictors of immune status. Cleavage of Fc fragments from anti-virus or anti-peptide IgG results in a marked decrease in MPT titres although binding to virus in ELISA is unaffected, indicating that intact antibodies are required for in vivo clearance of FMDV. Cross-protection studies demonstrate that anti-peptide sera, while less potent than anti-viral sera in conferring passive immunity against FMDV challenge, have a wider protective range than anti-viral sera within the O serotype and also between O and A serotypes. Possible qualitative differences between anti-viral and anti-peptide sera are discussed in the light of these findings.
Mulcahy
G
G
AFRC Institute for Animal Health, Pirbright Laboratory, Woking, Surrey, UK.
Pullen
L A
LA
Gale
C
C
DiMarchi
R D
RD
Doel
T R
TR
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D005537:Aphthovirus / Q000276:immunology*; D005069:Evaluation Studies as Topic; D005536:Foot-and-Mouth Disease / Q000517:prevention & control; D007116:Immunization, Passive; D051379:Mice; D009500:Neutralization Tests; D014614:Vaccines, Synthetic / Q000494:pharmacology; D014765:Viral Vaccines / Q000494:pharmacology*
D000914:Antibodies, Viral; D014614:Vaccines, Synthetic; D014765:Viral Vaccines