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The assessment of efficacy of porcine reproductive respiratory syndrome virus inactivated vaccine based on the viral quantity and inactivation methods.

Kim H, Kim HK, Jung JH, Choi YJ, Kim J, Um CG, Hyun SB, Shin S, Lee B, Jang G, Kang BK, Moon HJ, Song DS - Virol. J. (2011)

Bottom Line: While viremia did not reduce in the vaccinated groups, the IDEXX-ELISA-specific immunoglobulin G increased more rapidly and to significantly greater levels 7 days after the challenge in all the vaccinated groups compared to the non-vaccinated groups (p < 0.05).The inactivated vaccine failed to show the humoral immunity, but it showed different immune response after the challenge compared to mock group.Although the 106 PFU/mL-vaccinated and BEI-inactivated groups showed significantly greater VN titers 22 days after challenge, all the groups were already negative for viremia.

View Article: PubMed Central - HTML - PubMed

Affiliation: Optifarm Solution Inc., 48 Songnam-ri, Seonggeo-eup, Cheonan, Korea.

ABSTRACT

Background: There have been many efforts to develop efficient vaccines for the control of porcine reproductive and respiratory syndrome virus (PRRSV). Although inactivated PRRSV vaccines are preferred for their safety, they are weak at inducing humoral immune responses and controlling field PRRSV infection, especially when heterologous viruses are involved.

Results: In all groups, the sample to positive (S/P) ratio of IDEXX ELISA and the virus neutralization (VN) titer remained negative until challenge. While viremia did not reduce in the vaccinated groups, the IDEXX-ELISA-specific immunoglobulin G increased more rapidly and to significantly greater levels 7 days after the challenge in all the vaccinated groups compared to the non-vaccinated groups (p < 0.05). VN titer was significantly different in the 106 PFU/mL PRRSV vaccine-inoculated and binary ethylenimine (BEI)-inactivated groups 22 days after challenge (p < 0.05). Consequently, the inactivated vaccines tested in this study provided weak memory responses with sequential challenge without any obvious active immune responses in the vaccinated pigs.

Conclusions: The inactivated vaccine failed to show the humoral immunity, but it showed different immune response after the challenge compared to mock group. Although the 106 PFU/mL-vaccinated and BEI-inactivated groups showed significantly greater VN titers 22 days after challenge, all the groups were already negative for viremia.

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Related in: MedlinePlus

Virus-specific neutralization titer according to virus inactivation method using the samples 22 days after challenge. The virus neutralization test titer of the BEI-inactivated group was significantly greater than the formalin- and β-propiolactone-inactivated groups (p < 0.05).
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Figure 8: Virus-specific neutralization titer according to virus inactivation method using the samples 22 days after challenge. The virus neutralization test titer of the BEI-inactivated group was significantly greater than the formalin- and β-propiolactone-inactivated groups (p < 0.05).

Mentions: On the last day after challenge, the serum samples were analyzed to determine differences in VN titer, according to inactivation method used to prepare vaccines (Figure 8). Before challenge, all experimental groups were measured by VN test, and all groups were negative. Twenty-two days after the challenge, the BEI-inactivated group had a significantly higher titer compared to the formalin- and β-propiolactone-inactivated groups (p < 0.01).


The assessment of efficacy of porcine reproductive respiratory syndrome virus inactivated vaccine based on the viral quantity and inactivation methods.

Kim H, Kim HK, Jung JH, Choi YJ, Kim J, Um CG, Hyun SB, Shin S, Lee B, Jang G, Kang BK, Moon HJ, Song DS - Virol. J. (2011)

Virus-specific neutralization titer according to virus inactivation method using the samples 22 days after challenge. The virus neutralization test titer of the BEI-inactivated group was significantly greater than the formalin- and β-propiolactone-inactivated groups (p < 0.05).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3141684&req=5

Figure 8: Virus-specific neutralization titer according to virus inactivation method using the samples 22 days after challenge. The virus neutralization test titer of the BEI-inactivated group was significantly greater than the formalin- and β-propiolactone-inactivated groups (p < 0.05).
Mentions: On the last day after challenge, the serum samples were analyzed to determine differences in VN titer, according to inactivation method used to prepare vaccines (Figure 8). Before challenge, all experimental groups were measured by VN test, and all groups were negative. Twenty-two days after the challenge, the BEI-inactivated group had a significantly higher titer compared to the formalin- and β-propiolactone-inactivated groups (p < 0.01).

Bottom Line: While viremia did not reduce in the vaccinated groups, the IDEXX-ELISA-specific immunoglobulin G increased more rapidly and to significantly greater levels 7 days after the challenge in all the vaccinated groups compared to the non-vaccinated groups (p < 0.05).The inactivated vaccine failed to show the humoral immunity, but it showed different immune response after the challenge compared to mock group.Although the 106 PFU/mL-vaccinated and BEI-inactivated groups showed significantly greater VN titers 22 days after challenge, all the groups were already negative for viremia.

View Article: PubMed Central - HTML - PubMed

Affiliation: Optifarm Solution Inc., 48 Songnam-ri, Seonggeo-eup, Cheonan, Korea.

ABSTRACT

Background: There have been many efforts to develop efficient vaccines for the control of porcine reproductive and respiratory syndrome virus (PRRSV). Although inactivated PRRSV vaccines are preferred for their safety, they are weak at inducing humoral immune responses and controlling field PRRSV infection, especially when heterologous viruses are involved.

Results: In all groups, the sample to positive (S/P) ratio of IDEXX ELISA and the virus neutralization (VN) titer remained negative until challenge. While viremia did not reduce in the vaccinated groups, the IDEXX-ELISA-specific immunoglobulin G increased more rapidly and to significantly greater levels 7 days after the challenge in all the vaccinated groups compared to the non-vaccinated groups (p < 0.05). VN titer was significantly different in the 106 PFU/mL PRRSV vaccine-inoculated and binary ethylenimine (BEI)-inactivated groups 22 days after challenge (p < 0.05). Consequently, the inactivated vaccines tested in this study provided weak memory responses with sequential challenge without any obvious active immune responses in the vaccinated pigs.

Conclusions: The inactivated vaccine failed to show the humoral immunity, but it showed different immune response after the challenge compared to mock group. Although the 106 PFU/mL-vaccinated and BEI-inactivated groups showed significantly greater VN titers 22 days after challenge, all the groups were already negative for viremia.

Show MeSH
Related in: MedlinePlus