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Brucella abortus strain RB51 vaccine: immune response after calfhood vaccination and field investigation in Italian cattle population.

Tittarelli M, Bonfini B, De Massis F, Giovannini A, Di Ventura M, Nannini D, Caporale V - Clin. Dev. Immunol. (2008)

Bottom Line: The results indicate that the possibility to use RB51-CFT for the identification of cattle vaccinated at calfhood with RB51 is limited in time.The study outcomes indicate that in case of RB51-CFT positive results observed in officially Brucellosis-free (OBF) areas and, in any case, when an illegal use of RB51 vaccine is suspected, the use of the RB51-CFT alone is not sufficient to identify all the vaccinated animals.The design of a more sophisticated diagnostic protocol including an epidemiological investigation, the use of RB51-CFT, and the use of the skin test with RB51 as antigen is deemed more appropriate for the identification of RB51 vaccinated animals.

View Article: PubMed Central - PubMed

Affiliation: Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise G. Caporale, Campo Boario, 64100 Teramo, Italy. m.tittarelli@izs.it

ABSTRACT
Immune response to Brucella abortus strain RB51 vaccine was measured in cattle vaccinated at calfhood. After an increase at day 6 post-vaccination (pv), the antibody level recorded in the 10 vaccinated animals remained constant for two months, and then progressively decreased. All vaccinated animals remained negative from day 162 pv to the end of the study (day 300 pv). Only at days 13 and 14 pv the RB51-CFT showed 100% sensitivity (credibility interval (CI) 76.2%-100%). The results indicate that the possibility to use RB51-CFT for the identification of cattle vaccinated at calfhood with RB51 is limited in time. A field investigation was carried out on 26,975 sera collected on regional basis from the Italian cattle population. The study outcomes indicate that in case of RB51-CFT positive results observed in officially Brucellosis-free (OBF) areas and, in any case, when an illegal use of RB51 vaccine is suspected, the use of the RB51-CFT alone is not sufficient to identify all the vaccinated animals. The design of a more sophisticated diagnostic protocol including an epidemiological investigation, the use of RB51-CFT, and the use of the skin test with RB51 as antigen is deemed more appropriate for the identification of RB51 vaccinated animals.

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Percent of sera coming from the NationalSerum Bank (NSB, collected during the 2001–2003 period) and resulted positive to RB51-CFT, onregional basis.
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fig5: Percent of sera coming from the NationalSerum Bank (NSB, collected during the 2001–2003 period) and resulted positive to RB51-CFT, onregional basis.

Mentions: TheRB51-CFT threshold has been identified in the 100% of fixation at 1 : 4 serumdilution. This result corresponds to the 90th percentile of the distribution oftitres of all sera that have shown reactivity in the RB51-CFT and to the 99.9thpercentile of the distribution of titres of sera coming from Piedmont,Veneto and Fiuli-Venezia Giulia regions, andthe autonomous provinces of Trento and Bolzano.RB51-CFT results on NSB sera (2001–2003 period), expressed according to theregion of origin and as percent of animals resulted positive on tested, areshown in Figure 5. RB51-CFT results in NBEP sera (year 2004), expressed according to the region oforigin and animals resulted positive on tested, are shown in Figure 6. Giventhat they have been used for the threshold calculation, NSB sera from Piedmontregion, as well as NBEP sera from Veneto andFiuli-Venezia Giulia regions and the autonomous provinces of Trento and Bolzano, have not beenconsidered in Figures 5 and 6, respectively.


Brucella abortus strain RB51 vaccine: immune response after calfhood vaccination and field investigation in Italian cattle population.

Tittarelli M, Bonfini B, De Massis F, Giovannini A, Di Ventura M, Nannini D, Caporale V - Clin. Dev. Immunol. (2008)

Percent of sera coming from the NationalSerum Bank (NSB, collected during the 2001–2003 period) and resulted positive to RB51-CFT, onregional basis.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2291552&req=5

fig5: Percent of sera coming from the NationalSerum Bank (NSB, collected during the 2001–2003 period) and resulted positive to RB51-CFT, onregional basis.
Mentions: TheRB51-CFT threshold has been identified in the 100% of fixation at 1 : 4 serumdilution. This result corresponds to the 90th percentile of the distribution oftitres of all sera that have shown reactivity in the RB51-CFT and to the 99.9thpercentile of the distribution of titres of sera coming from Piedmont,Veneto and Fiuli-Venezia Giulia regions, andthe autonomous provinces of Trento and Bolzano.RB51-CFT results on NSB sera (2001–2003 period), expressed according to theregion of origin and as percent of animals resulted positive on tested, areshown in Figure 5. RB51-CFT results in NBEP sera (year 2004), expressed according to the region oforigin and animals resulted positive on tested, are shown in Figure 6. Giventhat they have been used for the threshold calculation, NSB sera from Piedmontregion, as well as NBEP sera from Veneto andFiuli-Venezia Giulia regions and the autonomous provinces of Trento and Bolzano, have not beenconsidered in Figures 5 and 6, respectively.

Bottom Line: The results indicate that the possibility to use RB51-CFT for the identification of cattle vaccinated at calfhood with RB51 is limited in time.The study outcomes indicate that in case of RB51-CFT positive results observed in officially Brucellosis-free (OBF) areas and, in any case, when an illegal use of RB51 vaccine is suspected, the use of the RB51-CFT alone is not sufficient to identify all the vaccinated animals.The design of a more sophisticated diagnostic protocol including an epidemiological investigation, the use of RB51-CFT, and the use of the skin test with RB51 as antigen is deemed more appropriate for the identification of RB51 vaccinated animals.

View Article: PubMed Central - PubMed

Affiliation: Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise G. Caporale, Campo Boario, 64100 Teramo, Italy. m.tittarelli@izs.it

ABSTRACT
Immune response to Brucella abortus strain RB51 vaccine was measured in cattle vaccinated at calfhood. After an increase at day 6 post-vaccination (pv), the antibody level recorded in the 10 vaccinated animals remained constant for two months, and then progressively decreased. All vaccinated animals remained negative from day 162 pv to the end of the study (day 300 pv). Only at days 13 and 14 pv the RB51-CFT showed 100% sensitivity (credibility interval (CI) 76.2%-100%). The results indicate that the possibility to use RB51-CFT for the identification of cattle vaccinated at calfhood with RB51 is limited in time. A field investigation was carried out on 26,975 sera collected on regional basis from the Italian cattle population. The study outcomes indicate that in case of RB51-CFT positive results observed in officially Brucellosis-free (OBF) areas and, in any case, when an illegal use of RB51 vaccine is suspected, the use of the RB51-CFT alone is not sufficient to identify all the vaccinated animals. The design of a more sophisticated diagnostic protocol including an epidemiological investigation, the use of RB51-CFT, and the use of the skin test with RB51 as antigen is deemed more appropriate for the identification of RB51 vaccinated animals.

Show MeSH