PMID- 17560818
OWN - NLM
STAT- MEDLINE
DCOM- 20080627
LR  - 20220317
IS  - 1090-0233 (Print)
IS  - 1090-0233 (Linking)
VI  - 175
IP  - 3
DP  - 2008 Mar
TI  - Similarity of European porcine reproductive and respiratory syndrome virus 
      strains to vaccine strain is not necessarily predictive of the degree of 
      protective immunity conferred.
PG  - 356-63
AB  - The objective of this study was to determine the degree of protection conferred 
      by a Lelystad-like modified live virus (MLV) vaccine against a heterologous 
      wild-type porcine reproductive and respiratory syndrome virus (PRRSV) isolate of 
      the same cluster. For this purpose, fourteen 3-week-old piglets were divided into 
      three groups: Group A pigs were vaccinated with a modified live virus vaccine, 
      Group B pigs were used as positive controls, and Group C pigs as negative 
      controls. Twenty-eight days after the last dose of vaccine, all pigs in Groups A 
      and B were inoculated with the Spanish PRRSV strain 5710. To evaluate efficacy, 
      clinical signs were recorded and the presence of challenge virus was determined 
      by virus isolation in blood samples and nasal swabs collected at various time 
      points post-challenge (p.c.) and in tissue samples collected at necropsy 24 days 
      p.c. After challenge, moderate clinical signs were observed in pigs from Groups A 
      and B. In addition, all vaccinated pigs were viremic at least once, although 
      viremia tended to be more sporadic in this group than in Group B pigs. PRRSV was 
      detected in at least one tissue sample from four out of five pigs from Group A 
      and in all pigs from Group B. The results indicate that the protection conferred 
      by the MLV vaccine used in this study against a closely related virulent strain 
      was only partial. The findings suggest that the degree of genetic homology of 
      ORF5 between MLV vaccine and challenge isolate is not a good predictor of vaccine 
      efficacy.
FAU - Prieto, Cinta
AU  - Prieto C
AD  - Dpto. de Sanidad Animal, Facultad de Veterinaria, Universidad Complutense de 
      Madrid, Madrid, Spain.
FAU - Alvarez, Esther
AU  - Alvarez E
FAU - Martinez-Lobo, Francisco J
AU  - Martinez-Lobo FJ
FAU - Simarro, Isabel
AU  - Simarro I
FAU - Castro, Jose M
AU  - Castro JM
LA  - eng
PT  - Journal Article
PT  - Randomized Controlled Trial
PT  - Research Support, Non-U.S. Gov't
DEP - 20070608
PL  - England
TA  - Vet J
JT  - Veterinary journal (London, England : 1997)
JID - 9706281
RN  - 0 (Antibodies, Viral)
RN  - 0 (Viral Vaccines)
SB  - IM
MH  - Animals
MH  - Antibodies, Viral/blood
MH  - Enzyme-Linked Immunosorbent Assay/veterinary
MH  - Europe/epidemiology
MH  - Nose/virology
MH  - Porcine Reproductive and Respiratory Syndrome/blood/immunology/*prevention & 
      control/virology
MH  - Porcine respiratory and reproductive syndrome virus/*immunology/isolation & 
      purification
MH  - Swine
MH  - Vaccination/veterinary
MH  - Viral Vaccines/administration & dosage/*immunology
EDAT- 2007/06/15 09:00
MHDA- 2008/06/28 09:00
CRDT- 2007/06/15 09:00
PHST- 2006/10/30 00:00 [received]
PHST- 2006/12/28 00:00 [revised]
PHST- 2007/01/26 00:00 [accepted]
PHST- 2007/06/15 09:00 [pubmed]
PHST- 2008/06/28 09:00 [medline]
PHST- 2007/06/15 09:00 [entrez]
AID - S1090-0233(07)00057-3 [pii]
AID - 10.1016/j.tvjl.2007.01.021 [doi]
PST - ppublish
SO  - Vet J. 2008 Mar;175(3):356-63. doi: 10.1016/j.tvjl.2007.01.021. Epub 2007 Jun 8.