Inactivated recombinant Escherichia coli as a candidate vaccine against Clostridium perfringens alpha toxin in sheep

Humoral Immune Response Evaluation in Horses Vaccinated with Recombinant Clostridium perfringens Toxoids Alpha and Beta for 12 Months

“…After day 210, antibodies were not detected in any of the studied groups, which may have been a limitation of the immunodiagnostic technique; the test level used in serum neutralization detects no antibody titers below 4 IU/mL for anti-CPA, and 10 IU/mL for anti-CPB [ 15 , 23 ]. However, this could have also been related to vaccination protocols or even to the type of adjuvant used, which requires the development of new vaccine strategies that propose semiannual vaccination protocols, as well as the use and development of new adjuvant and immunostimulant molecules to maintain circulating neutralizing antibody levels for periods of up to one year.…”

“…Over the last decade, studies involving the production and evaluation of clostridial recombinant vaccines have shown that these immunobiological agents are an important alternative to inducing humoral immune responses in farm animals, achieving higher neutralizing antibody titers when compared to conventional commercial vaccines [ 13 , 14 , 15 , 16 , 17 ]. Thus, the objective of this study was to serve as a pioneer in the use, evaluation and comparison of the humoral immune response duration in horses immunized with recombinant vaccines containing different concentrations (100, 200 and 400 µg) of C. perfringens recombinant alpha (rCPA) and beta (rCPB) proteins for 12 months.…”

Measurement over 1 Year of Neutralizing Antibodies in Cattle Immunized with Trivalent Vaccines Recombinant Alpha, Beta and Epsilon of Clostridium perfringens

“…Recombinant proteins have shown promising results in the induction of neutralizing antibodies in different species, reaching the minimum titers required by law and higher than those obtained with commercial vaccines [ 3 , 4 , 15 , 16 , 17 , 18 , 19 , 20 , 21 ]. However, most of these studies involve potency tests, evaluating the production of neutralizing antibodies only at 56 days after the first vaccination, only two of them involving vaccines against botulism [ 12 , 18 ] among those that have evaluated the duration of the induced protection time in immunized animals.…”

“…Regarding the longevity of the induced immune response, it showed detectable antibody levels up to 150 days, but only for anti-CPB and anti-ETX. In recent years, other studies have also reported that the antibody titers induced by commercial clostridial vaccines were lower than those obtained with recombinant vaccines using the same adjuvant, aluminum hydroxide [ 10 , 15 , 16 , 17 , 19 ]. Augusto de Oliveira et al [ 22 ] evaluated the humoral immune response of cattle inoculated with polyvalent commercial vaccines containing C. botulinum toxoids type C and D (BoNTs) and the C. perfringens ETX toxoid for 1 year.…”

“…Recombinant clostridial vaccines are viable alternatives to conventional commercial production [ 2 , 3 , 4 , 10 , 11 , 15 , 16 , 17 , 18 , 19 , 20 ], eliciting the production of neutralizing antibodies to within the levels required by law. However, studies on the modulation of the animal immune system are still needed to establish the longevity of the humoral immune response induced by different doses of recombinant proteins [ 3 ].…”