PMID- 10451216
OWN - NLM
STAT- MEDLINE
DCOM- 19991015
LR  - 20061115
IS  - 0002-9645 (Print)
IS  - 0002-9645 (Linking)
VI  - 60
IP  - 8
DP  - 1999 Aug
TI  - Evaluation of protective immunity in gilts inoculated with the NADC-8 isolate of 
      porcine reproductive and respiratory syndrome virus (PRRSV) and challenge-exposed 
      with an antigenically distinct PRRSV isolate.
PG  - 1022-7
AB  - OBJECTIVES: To determine whether intrauterine inoculation of porcine reproductive 
      and respiratory syndrome virus (PRRSV) interferes with conception and whether 
      exposure to one strain of PRRSV provides protection against challenge-exposure 
      (CE) with homologous or heterologous strains of PRRSV. ANIMALS: 40 gilts. 
      PROCEDURE: Gilts were inoculated by intrauterine administration of a PRRSV 
      isolate (NADC-8) at breeding. Inoculated and noninoculated gilts were exposed 
      oronasally to homologous (NADC-8) or heterologous (European isolate) PRRSV during 
      late gestation. Specimens from gilts and fetuses were tested against CE virus. 
      Lack of virus in gilts indicated protective immunity for the dam, in fetuses 
      indicated protection of gilt from reproductive losses, and in both groups 
      indicated complete protection. RESULTS: In the homologous CE group, interval from 
      inoculation to CE ranged from 90 to 205 days, and protection was complete. In the 
      heterologous CE group, interval from inoculation to CE ranged from 90 to 170 
      days, and protection was incomplete. The CE virus was detected in gilts 
      necropsied 134 to 170 days after CE and in a litter necropsied 170 days after CE. 
      CONCLUSIONS: Homologous protection can be induced in gilts by exposure to live 
      PRRSV. Heterologous protection from reproductive losses can be induced in gilts 
      by exposure to live PRRSV; however, this protection is incomplete and may have a 
      shorter duration than homologous protection. CLINICAL RELEVANCE: Exposure of 
      swine to enzootic PRRSV will provide protection against homologous PRRSV-induced 
      reproductive losses. Extent and duration of protection against heterologous PRRSV 
      may be variable and dependent on antigenic relatedness of the virus strains used 
      for inoculation and CE.
FAU - Lager, K M
AU  - Lager KM
AD  - Virology Swine Research Unit, National Animal Disease Center, USDA, Agricultural 
      Research Service, Ames, IA 50010, USA.
FAU - Mengeling, W L
AU  - Mengeling WL
FAU - Brockmeier, S L
AU  - Brockmeier SL
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PL  - United States
TA  - Am J Vet Res
JT  - American journal of veterinary research
JID - 0375011
RN  - 0 (Antigens, Viral)
SB  - IM
MH  - Animals
MH  - Antibody Formation/immunology
MH  - Antigens, Viral/immunology
MH  - Breeding
MH  - Bronchoalveolar Lavage Fluid/virology
MH  - Cytopathogenic Effect, Viral
MH  - Female
MH  - Fetal Blood/virology
MH  - Immunization/methods/*veterinary
MH  - Male
MH  - Porcine Reproductive and Respiratory Syndrome/*immunology/*prevention & control
MH  - Porcine respiratory and reproductive syndrome virus/*immunology
MH  - Pregnancy
MH  - Swine
EDAT- 1999/08/18 00:00
MHDA- 1999/08/18 00:01
CRDT- 1999/08/18 00:00
PHST- 1999/08/18 00:00 [pubmed]
PHST- 1999/08/18 00:01 [medline]
PHST- 1999/08/18 00:00 [entrez]
PST - ppublish
SO  - Am J Vet Res. 1999 Aug;60(8):1022-7.