Protective efficacy of a Classical swine fever virus C-strain deletion mutant and ability to differentiate invected from vaccinated animals
Kortekaas, J.A. ; Ketelaar, J.H.E. ; Vloet, R.P.M. ; Loeffen, W.L.A. - \ 2011
Veterinary Microbiology 147 (2011)1-2. - ISSN 0378-1135 - p. 11 - 18.
marker vaccine - structural glycoprotein - chimeric pestivirus - pigs - csfv - e2 - virulence - identification - transmission - epitope
Classical swine fever (CSF) continues to be the most economically damaging pig disease in the world. The disease can be effectively controlled by vaccination with the live C-strain vaccine. This vaccine, however, does not enable the serological differentiation between infected and vaccinated animals (DIVA) and its use can therefore impose severe trade restrictions. CSF-specific diagnostic ELISAs detect antibodies directed against the conserved and immunodominant A domain of the E2 structural glycoprotein. We previously reported the production of a C-strain virus in which the immunodominant TAVSPTTLR epitope of the A domain is stably mutated with the aim to render the virus suitable as a DIVA vaccine. We here report that a single vaccination with this vaccine virus protected pigs from a lethal challenge dose of the highly virulent Brescia strain. Analysis of the sera, however, demonstrated that a commercially available E2 ELISA was unsuitable as an accompanying DIVA test.
Efficacy of intradermally administrated E2 subunit vaccines in reducing horizontal transmission of classical swine fever virus
Dortmans, J.C.F.M. ; Loeffen, W.L.A. ; Weerdmeester, K. ; Poel, W.H.M. van der; Bruin, M.G.M. de - \ 2008
Vaccine 26 (2008)9. - ISSN 0264-410X - p. 1235 - 1242.
aujeszkys-disease - e-rns - marker vaccines - dna vaccination - pigs - infection - csfv - challenge - influenza - antibody
To investigate if intradermal (ID) vaccination and intramuscular (IM) vaccination result in a comparable reduction of horizontal transmission of classical swine fever virus (CSFV), two registered E2 subunit marker vaccines were examined. Vaccine A was a water-in-oil emulsion containing the E2 glycoprotein originating from the Alfort/Tübingen strain and vaccine B was a water¿oil¿water emulsion containing the E2 glycoprotein originating from the Brescia strain. Eight groups, of ten pigs each, were vaccinated with either vaccine A or B, intramuscularly (IM) or intradermally (ID). Two different vaccination-challenge intervals were used for each vaccine. Furthermore, one group was vaccinated with a tenfold ID dose of vaccine A and one non-vaccinated group served as a control group. Five pigs from each group were challenged with the moderately virulent CSFV strain Paderborn, while the remaining five pigs served as contacts. Using vaccine A, full transmission to all contact pigs in both ID vaccinated groups occurred. No virus transmission was observed when IM vaccinated pigs were challenged 14 days post-vaccination (14 dpv) whereas only one out of five contact pig became infected when they were challenged 10 dpv. Using vaccine B no virus transmission was observed when pigs were ID or IM vaccinated and challenged 10 dpv. When challenged 3 dpv full transmission occurred in the ID vaccinated group, whereas four out of five contact pigs became infected in the IM vaccinated group. This result indicates that ID vaccination does not result in better protection against horizontal CSFV transmission compared to IM vaccination, for the vaccines studied.