An E2 sub-unit marker vaccine does not prevent horizontal or vertical transmission of classical swine fever virus.
An experimental infection with classical swine fever (CSF) virus in E2 sub-unit marker vaccine vaccinated gilts was conducted in order to evaluate the effect of vaccination on virus transmission and course of the disease. Therefore, clinical signs as well as horizontal and vertical virus transmission were monitored in two inoculated, non-vaccinated and 10 vaccinated conventional gilts, housed in individual sow boxes. Within 10 days post-inoculation, all vaccinated gilts became infected. Depending on the definition of the infectious period, two different estimates of R0 were calculated (R0=14.8 and 3.3), both significantly larger than 1 (P<0.01). In three out of the eight vaccinated pregnant gilts vertical virus transmission occurred, resulting in infected offspring. Based on the results of this experiment, it can be concluded that double vaccination with an E2 sub-unit marker vaccine only protects pregnant gilts from the clinical course of the disease but does not prevent horizontal nor vertical spread of the CSF virus.
Dewulf
J
J
Department of Reproduction, Obstetrics and Herd Health, School of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820, Merelbeke, Belgium. jeroen.dewulf@rug.ac.be
Laevens
H
H
Koenen
F
F
Mintiens
K
K
de Kruif
A
A
D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis / Q000097:blood / Q000276:immunology; D006691:Classical Swine Fever / Q000276:immunology / Q000517:prevention & control* / Q000635:transmission / Q000821:virology; D006692:Classical Swine Fever Virus / Q000276:immunology*; D018562:Disease Transmission, Infectious / Q000517:prevention & control; D004341:Drug Evaluation; D005260:Female; D018445:Infectious Disease Transmission, Vertical / Q000517:prevention & control; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000821:virology; D014611:Vaccination / Q000662:veterinary*; D022581:Vaccines, Marker; D014614:Vaccines, Synthetic / Q000276:immunology; D014759:Viral Envelope Proteins / Q000276:immunology*; D014765:Viral Vaccines / Q000276:immunology*
D000914:Antibodies, Viral; D022581:Vaccines, Marker; D014614:Vaccines, Synthetic; D014759:Viral Envelope Proteins; D014765:Viral Vaccines; C087086:glycoprotein E2, classical swine fever virus