Martínez-Lobo FJ, de Lome LC,
Díez-Fuertes F, Segalés J, García-Artiga C,Simarro I, Castro JM, Prieto C.
Safety of Porcine Reproductive and Respiratory Syndrome Modified Live Virus
(MLV) vaccine strains in a young pig infection model. Vet Res. 2013 Dec
5;44:115. doi: 10.1186/1297-9716-44-115.
Abstract
The objective of this study was to
compare the safety of all modified live virus vaccines commercially available
in Europe against Porcine Reproductive and Respiratory Syndrome Virus (PRRSV)
under the same experimental conditions. For this purpose, one hundred and
twenty three-week-old piglets, divided into fivegroups, were used. On day 0 of
the experiment, nine pigs per group were removed and the remaining fifteen were
vaccinated with the commercial vaccines Ingelvac PRRS MLV, Amervac PRRS,
Pyrsvac-183 and Porcilis PRRS by the IM route or were mock vaccinated and used
as controls. On day 3, the nine unvaccinated pigs were re-introduced into their
respective groups and served as sentinel pigs. Clinical signs were recorded
daily and lung lesions were determined on days 7, 14 and 21, when 5 vaccinated
pigs per group were euthanized. Blood samples and swabs were taken every three
days and different organs were collected at necropsy to determine the presence
of PRRSV. None of the vaccines studied caused detectable clinical signs in
vaccinated pigs although lung lesions were found. Altogether, these results
indicate that all vaccines can be considered clinically safe. However, some
differences were found in virological parameters. Thus, neitherPyrsvac-183 nor
Porcilis PRRS could be detected in porcine alveolar macrophage(PAM) cultures or
in lung sections used to determine PRRSV by immunohistochemistry, indicating
that these viruses might have lost their ability to replicate in PAM. This
inability to replicate in PAM might be related to the lower transmission rate
and the delay in the onset of viremia observed in these groups.
PMCID: PMC4028782PMID: 24308693 [PubMed - indexed for MEDLINE]
No comments:
Post a Comment