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Production results from piglets vaccinated in a field study in Spain with a Type 1 Porcine Respiratory and Reproductive virus modified live vaccine

View Article: PubMed Central - PubMed

ABSTRACT

Background: PRRS is a viral disease of pigs and sows that is one of the most costly to the pig industry worldwide. The disease can be controlled by focusing on different aspects. One of them is the vaccination of piglets, which is more controversial and difficult to manage than the vaccination of sows. However, pig producers could consider a piglet vaccination strategy if it reduces the negative clinical disease and improves zootechnical performance, decreases the probability to be infected and/or reduces the spread of the virus once the vaccinated piglet is infected. The efficacy of a novel PRRS modified live vaccine (Ingelvac PRRSFLEX® EU) was studied in a blinded, side-by-side placebo controlled field study of piglet vaccination including piglets weaned for three consecutive weeks (week groups 1, 2 and 3).

Results: This study established that PRRS piglet vaccination resulted in significantly better weight gain, seen as early as 4 weeks after vaccination, in naturally challenged pigs. Vaccine efficacy was supported by statistically significant increases in Average Daily Weight Gain (ADWG) among week group 3 vaccinated pigs from vaccination to the end of the study and statistically significant increases in bodyweight and ADWG from inclusion to 10 weeks of age in week group 2 vaccinated piglets. However, no differences were noted in week group 1 presumably because more than 30 % of the vaccinated pigs were viremic at the time of vaccination. Furthermore, the proportion of pigs showing any abnormal clinical sign at least once at any of the examination time points was lower in vaccinated pigs than in control pigs. Based on the viremia results (qPCR), early onset of PRRS was detected in this herd. Viremia occurred at the time of vaccination in week group 1 and shortly after vaccination in week groups 2 and 3. Peak wild type PRRSV infection was assumed at 4 weeks post vaccination in all groups based on the number of PRRS positive pigs in the control groups.

Conclusion: This study establishes that vaccination of piglets with Ingelvac PRRSFLEX® EU at 4 weeks of age improves weight gain and reduces the appearance of clinical sings during the growing period, even when the piglets are infected shortly after vaccination.

Electronic supplementary material: The online version of this article (doi:10.1186/s40813-016-0038-x) contains supplementary material, which is available to authorized users.

No MeSH data available.


Related in: MedlinePlus

Viremia in % positive pigs (qualitative) by qPCR at the different sampling times in 69 unvaccinated pigs (22, 24 and 23 in weeks groups 1, 2 and 3, respectively). Percentage of positive pigs and confidence interval 95 %
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Fig3: Viremia in % positive pigs (qualitative) by qPCR at the different sampling times in 69 unvaccinated pigs (22, 24 and 23 in weeks groups 1, 2 and 3, respectively). Percentage of positive pigs and confidence interval 95 %

Mentions: Percentage of PRRSV RNA positive pigs by qPCR throughout the study is shown in Figs. 2 and 3 for vaccinated and unvaccinated pigs. Peak of viremia with 80 % (68–88; 95 % CI) of vaccinated pigs and 83 % (72–91 %; 95 % CI) of unvaccinated pigs tested positive was at 4 weeks after vaccination. For all the time points, no differences were observed in the prevalence of viremic animals between vaccinated and unvaccinated pigs. For pigs in WG1, the PRRSV field infection was on-going at vaccination time with 38 % (19–59 %; 95 % CI) of vaccinated pigs and 27 % (11–50 %; 95 % CI) of unvaccinated pigs tested positive (see Figs. 2 and 3 at week 0). Notably, none of the vaccinated animals tested positive by PRRSV qPCR at the end of fattening while 3 % of the unvaccinated animals were still viremic at the end of fattening.Fig. 2


Production results from piglets vaccinated in a field study in Spain with a Type 1 Porcine Respiratory and Reproductive virus modified live vaccine
Viremia in % positive pigs (qualitative) by qPCR at the different sampling times in 69 unvaccinated pigs (22, 24 and 23 in weeks groups 1, 2 and 3, respectively). Percentage of positive pigs and confidence interval 95 %
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC5382400&req=5

Fig3: Viremia in % positive pigs (qualitative) by qPCR at the different sampling times in 69 unvaccinated pigs (22, 24 and 23 in weeks groups 1, 2 and 3, respectively). Percentage of positive pigs and confidence interval 95 %
Mentions: Percentage of PRRSV RNA positive pigs by qPCR throughout the study is shown in Figs. 2 and 3 for vaccinated and unvaccinated pigs. Peak of viremia with 80 % (68–88; 95 % CI) of vaccinated pigs and 83 % (72–91 %; 95 % CI) of unvaccinated pigs tested positive was at 4 weeks after vaccination. For all the time points, no differences were observed in the prevalence of viremic animals between vaccinated and unvaccinated pigs. For pigs in WG1, the PRRSV field infection was on-going at vaccination time with 38 % (19–59 %; 95 % CI) of vaccinated pigs and 27 % (11–50 %; 95 % CI) of unvaccinated pigs tested positive (see Figs. 2 and 3 at week 0). Notably, none of the vaccinated animals tested positive by PRRSV qPCR at the end of fattening while 3 % of the unvaccinated animals were still viremic at the end of fattening.Fig. 2

View Article: PubMed Central - PubMed

ABSTRACT

Background: PRRS is a viral disease of pigs and sows that is one of the most costly to the pig industry worldwide. The disease can be controlled by focusing on different aspects. One of them is the vaccination of piglets, which is more controversial and difficult to manage than the vaccination of sows. However, pig producers could consider a piglet vaccination strategy if it reduces the negative clinical disease and improves zootechnical performance, decreases the probability to be infected and/or reduces the spread of the virus once the vaccinated piglet is infected. The efficacy of a novel PRRS modified live vaccine (Ingelvac PRRSFLEX® EU) was studied in a blinded, side-by-side placebo controlled field study of piglet vaccination including piglets weaned for three consecutive weeks (week groups 1, 2 and 3).

Results: This study established that PRRS piglet vaccination resulted in significantly better weight gain, seen as early as 4 weeks after vaccination, in naturally challenged pigs. Vaccine efficacy was supported by statistically significant increases in Average Daily Weight Gain (ADWG) among week group 3 vaccinated pigs from vaccination to the end of the study and statistically significant increases in bodyweight and ADWG from inclusion to 10 weeks of age in week group 2 vaccinated piglets. However, no differences were noted in week group 1 presumably because more than 30 % of the vaccinated pigs were viremic at the time of vaccination. Furthermore, the proportion of pigs showing any abnormal clinical sign at least once at any of the examination time points was lower in vaccinated pigs than in control pigs. Based on the viremia results (qPCR), early onset of PRRS was detected in this herd. Viremia occurred at the time of vaccination in week group 1 and shortly after vaccination in week groups 2 and 3. Peak wild type PRRSV infection was assumed at 4 weeks post vaccination in all groups based on the number of PRRS positive pigs in the control groups.

Conclusion: This study establishes that vaccination of piglets with Ingelvac PRRSFLEX® EU at 4 weeks of age improves weight gain and reduces the appearance of clinical sings during the growing period, even when the piglets are infected shortly after vaccination.

Electronic supplementary material: The online version of this article (doi:10.1186/s40813-016-0038-x) contains supplementary material, which is available to authorized users.

No MeSH data available.


Related in: MedlinePlus