PMID- 9453124
OWN - NLM
STAT- MEDLINE
DCOM- 19980226
LR  - 20190831
IS  - 0378-1135 (Print)
IS  - 0378-1135 (Linking)
VI  - 58
IP  - 2-4
DP  - 1997 Nov
TI  - Duration of homologous porcine reproductive and respiratory syndrome virus 
      immunity in pregnant swine.
PG  - 127-33
AB  - The duration of porcine reproductive and respiratory syndrome virus (PRRSV) 
      homologous immunity was tested in this study and found to last for at least 604 
      days post experimental exposure to field PRRSV. Eleven gilts (group A) received a 
      primary exposure to field PRRSV by either an oronasal (n = 6) or an intrauterine 
      (n = 5) route. The gilts were naturally bred at selected times (143 to 514 days) 
      after primary virus exposure. They were oronasally exposed a second time to the 
      same strain of virus on or about gestation day 90. Ten age-matched control sows 
      free of PRRSV-specific antibody from the same source farm (group B) were 
      naturally bred and were oronasally exposed to aliquots of the homologous 
      challenge virus on or about gestation day 90. Nine of the 11 gilts in group A and 
      all animals in group B became pregnant following one breeding cycle. The two 
      nonpregnant gilts in group A were each naturally bred during four additional 
      estrus cycles and neither became pregnant. They were exposed to homologous 
      challenge virus 562 and 604 days post primary exposure, respectively. All animals 
      were necropsied 21 days post homologous challenge. Sera and alveolar macrophages 
      from each dam, and sera from each fetus were tested for virus. Transplacental 
      infection was detected in 0/9 and 8/10 litters in groups A and B, respectively. 
      Virus was detected in 0/11 and 10/10 of the alveolar macrophage samples collected 
      in groups A and B, respectively. Serum was harvested at selected times throughout 
      the experiment and tested for PRRSV-specific antibody by indirect 
      immunofluorescence microscopy. All gilts in group A were seropositive for the 
      duration of the experiment, and all animals in group B seroconverted following 
      exposure to field PRRSV. This study shows that adult swine can produce a 
      homologous protective immunity after PRRSV exposure that may persist for the 
      production life of the animal.
FAU - Lager, K M
AU  - Lager KM
AD  - Virology Swine Research Unit, National Animal Disease Center, USDA, Ames, IA 
      50010, USA. klager@nadc.ars.usda.gov
FAU - Mengeling, W L
AU  - Mengeling WL
FAU - Brockmeier, S L
AU  - Brockmeier SL
LA  - eng
PT  - Journal Article
PL  - Netherlands
TA  - Vet Microbiol
JT  - Veterinary microbiology
JID - 7705469
RN  - 0 (Antibodies, Viral)
SB  - IM
MH  - Animals
MH  - Antibodies, Viral/blood
MH  - Female
MH  - Immunity, Active
MH  - Porcine Reproductive and Respiratory Syndrome/*immunology
MH  - Porcine respiratory and reproductive syndrome virus/*immunology/isolation & 
      purification
MH  - Pregnancy
MH  - Pregnancy Complications, Infectious/*immunology
MH  - Pregnancy, Animal/*immunology
MH  - Swine
MH  - Time Factors
MH  - Uterus
EDAT- 1998/02/07 00:00
MHDA- 1998/02/07 00:01
CRDT- 1998/02/07 00:00
PHST- 1998/02/07 00:00 [pubmed]
PHST- 1998/02/07 00:01 [medline]
PHST- 1998/02/07 00:00 [entrez]
AID - S0378-1135(97)00159-4 [pii]
AID - 10.1016/s0378-1135(97)00159-4 [doi]
PST - ppublish
SO  - Vet Microbiol. 1997 Nov;58(2-4):127-33. doi: 10.1016/s0378-1135(97)00159-4.