PMID- 15474708
OWN - NLM
STAT- MEDLINE
DCOM- 20041227
LR  - 20041011
IS  - 0264-410X (Print)
IS  - 0264-410X (Linking)
VI  - 22
IP  - 31-32
DP  - 2004 Oct 22
TI  - Impact of genetic diversity of European-type porcine reproductive and respiratory 
      syndrome virus strains on vaccine efficacy.
PG  - 4183-90
AB  - The aim of this study was to find out how efficiently pigs that are vaccinated 
      with an attenuated porcine reproductive and respiratory syndrome virus (PRRSV) 
      vaccine based on a virus from the Lelystad cluster are protected against a 
      European wild-type strain from the same or another genetic cluster. Two 
      experiments were performed. In each experiment, 5-week-old PRRSV-seronegative 
      pigs were vaccinated intramuscularly with 10(4.5) TCID50 of a commercial vaccine 
      based on a European virus strain from the Lelystad cluster. Non-vaccinated pigs 
      were included as controls. At 5, 9, 15, 20, 28, 35 and 42 days post vaccination 
      (PV), broncho-alveolar lavage (BAL) fluids and blood were collected to determine 
      vaccine virus quantities. Forty-nine days PV, pigs were challenged intranasally 
      with 10(6.0) TCID50 of a European wild-type strain, belonging either to the 
      Lelystad cluster (98% nucleotide identity in ORF5 with vaccine strain) 
      (experiment A) or to an Italian cluster (84% nucleotide identity in ORF5 with 
      vaccine strain) (experiment B). At 5, 9, 15, 20 and 27 days post challenge (PC), 
      BAL fluids and blood were collected to determine virus quantities. Vaccine virus 
      was first detected in BAL fluids and blood at 5 days PV and reached highest 
      quantities between 9 and 15 days PV. One pig was positive in its BAL fluid until 
      42 days PV. After challenge, virus was isolated from BAL fluids and blood of all 
      non-vaccinated control pigs. All vaccinated pigs challenged with the Lelystad 
      strain remained negative for virus, while virus was present in BAL fluids and 
      blood of all vaccinated pigs after challenge with the Italian strain. Mean virus 
      titres of the vaccinated pigs challenged with the Italian strain were 
      significantly lower than those of the non-vaccinated control pigs (P <0.05) at 9, 
      15 and 20 days PC. Thus, the genetic diversity within European-type PRRSV may 
      affect the efficacy of the current European-type vaccines.
FAU - Labarque, G
AU  - Labarque G
AD  - Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, 
      Salisburylaan 133, 9820 Merelbeke, Belgium.
FAU - Reeth, K Van
AU  - Reeth KV
FAU - Nauwynck, H
AU  - Nauwynck H
FAU - Drexler, C
AU  - Drexler C
FAU - Van Gucht, S
AU  - Van Gucht S
FAU - Pensaert, M
AU  - Pensaert M
LA  - eng
PT  - Journal Article
PL  - Netherlands
TA  - Vaccine
JT  - Vaccine
JID - 8406899
RN  - 0 (Viral Vaccines)
SB  - IM
MH  - Animals
MH  - Bronchoalveolar Lavage Fluid/cytology
MH  - Europe
MH  - Porcine Reproductive and Respiratory Syndrome/immunology/prevention & 
      control/virology
MH  - Porcine respiratory and reproductive syndrome virus/*genetics/*immunology
MH  - Swine/*immunology
MH  - Vaccination
MH  - Viral Vaccines/*genetics/*immunology
MH  - Virus Replication
EDAT- 2004/10/12 09:00
MHDA- 2004/12/28 09:00
CRDT- 2004/10/12 09:00
PHST- 2004/02/12 00:00 [received]
PHST- 2004/05/04 00:00 [revised]
PHST- 2004/05/12 00:00 [accepted]
PHST- 2004/10/12 09:00 [pubmed]
PHST- 2004/12/28 09:00 [medline]
PHST- 2004/10/12 09:00 [entrez]
AID - S0264-410X(04)00412-8 [pii]
AID - 10.1016/j.vaccine.2004.05.008 [doi]
PST - ppublish
SO  - Vaccine. 2004 Oct 22;22(31-32):4183-90. doi: 10.1016/j.vaccine.2004.05.008.