PMID- 30459958
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20220330
IS  - 2055-5660 (Print)
IS  - 2055-5660 (Electronic)
IS  - 2055-5660 (Linking)
VI  - 4
DP  - 2018
TI  - Vaccination of 1-day-old pigs with a porcine reproductive and respiratory 
      syndrome virus (PRRSV) modified live attenuated virus vaccine is able to overcome 
      maternal immunity.
PG  - 25
LID - 10.1186/s40813-018-0101-x [doi]
LID - 25
AB  - BACKGROUND: The objective of the study was to evaluate the influence of 
      maternally derived antibodies (MDA) on the efficacy of a PRRSV-1 based attenuated 
      vaccine, when administered in 1 day-old piglets by the intramuscular route. The 
      protective immunity of the modified live virus vaccine was evaluated in pigs born 
      from seropositive sows, vaccinated at 1 day of age, upon inoculation with a 
      PRRSV-1 isolate. The animals were challenged when the levels of MDAs detected by 
      seroneutralization test (SNT) in the non-vaccinated control group became 
      undetectable (10 weeks after vaccination). RESULTS: A protective effect of 
      vaccination was observed since a significant reduction of viral load in serum 
      compared to the control group was detected in all sampling days after challenge; 
      efficacy was supported by the significant reduction of nasal and oral shedding as 
      well as in rectal temperatures. Clinical signs were not expected after the 
      inoculation of a PRRSV-1 subtype 1 challenge strain. However, the challenge virus 
      was able to develop fever in 61% of the control pigs. Vaccination had a positive 
      impact on rectal temperatures since the percentage of pigs that had fever at 
      least once after challenge was reduced to 31% in vaccinated animals, and control 
      pigs had significantly higher rectal temperatures than vaccinated pigs 3 days 
      post-challenge. The lack of a vaccination effect in body weight gain was probably 
      due to the short evaluation period after challenge (10 days). In the vaccinated 
      group, 9/16 pigs (56%) experienced an increase in ELISA S/P ratio from the day of 
      vaccination to 67 days post-vaccination. All vaccinated pigs were seropositive 
      before challenge, indicating the development of an antibody response following 
      vaccination even in the face of MDAs. In contrast to ELISA results, only 2/16 
      vaccinated pigs developed neutralizing antibodies detectable by a SNT that used a 
      subtype 1 MA-104 adapted strain. Even in the absence of SN antibodies, vaccinated 
      pigs were protected from challenge with a heterologous strain. The role of 
      cell-mediated immunity should be considered, if protection was not mediated by SN 
      antibodies only. CONCLUSIONS: The efficacy of the attenuated PRRSV-1 vaccine in 
      1-day-old pigs seropositive to PRRSV prior to a PRRSV-1 challenge was 
      demonstrated by improvement of clinical, virological and immunological variables. 
      With the current experimental design, maternal immunity did not interfere with 
      the development of a protective immune response against a PRRSV-1 challenge, 
      after vaccination of 1 day-old pigs. Confirmation of these results under field 
      conditions will be needed.
FAU - Balasch, Monica
AU  - Balasch M
AUID- ORCID: 0000-0002-9971-6409
AD  - Zoetis Manufacturing & Research Spain S.L., Ctra. Camprodon s/n, Finca La Riba, 
      17813, Girona, Vall de Bianya Spain.
FAU - Fort, Maria
AU  - Fort M
AD  - Zoetis Manufacturing & Research Spain S.L., Ctra. Camprodon s/n, Finca La Riba, 
      17813, Girona, Vall de Bianya Spain.
FAU - Taylor, Lucas P
AU  - Taylor LP
AD  - 2Zoetis Inc., 333 Portage St, Kalamazoo, MI 49007 USA. ISNI: 0000 0004 1790 2553. 
      GRID: grid.463103.3
FAU - Calvert, Jay G
AU  - Calvert JG
AD  - 2Zoetis Inc., 333 Portage St, Kalamazoo, MI 49007 USA. ISNI: 0000 0004 1790 2553. 
      GRID: grid.463103.3
LA  - eng
PT  - Journal Article
DEP - 20181115
PL  - England
TA  - Porcine Health Manag
JT  - Porcine health management
JID - 101684126
PMC - PMC6237022
OTO - NOTNLM
OT  - Maternal-derived immunity
OT  - Modified live vaccine
OT  - Porcine reproductive and respiratory syndrome
COIS- The study protocol was approved by the Zoetis Manufacturing & Research Spain S.L. 
      Animal Welfare committee prior to the start of the experiment, and was reported 
      to the competent authorities.Not applicable.The authors declare that they have no 
      competing interests.Springer Nature remains neutral with regard to jurisdictional 
      claims in published maps and institutional affiliations.
EDAT- 2018/11/22 06:00
MHDA- 2018/11/22 06:01
PMCR- 2018/11/15
CRDT- 2018/11/22 06:00
PHST- 2018/07/17 00:00 [received]
PHST- 2018/10/03 00:00 [accepted]
PHST- 2018/11/22 06:00 [entrez]
PHST- 2018/11/22 06:00 [pubmed]
PHST- 2018/11/22 06:01 [medline]
PHST- 2018/11/15 00:00 [pmc-release]
AID - 101 [pii]
AID - 10.1186/s40813-018-0101-x [doi]
PST - epublish
SO  - Porcine Health Manag. 2018 Nov 15;4:25. doi: 10.1186/s40813-018-0101-x. 
      eCollection 2018.