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

Abstract

The alpha (CPA), beta (CPB) and epsilon (ETX) toxins of Clostridium perfringens are responsible for causing diseases that are difficult to eradicate and have lethal potential in production animals. Vaccination of herds is still the best control strategy. Recombinant clostridial vaccines have shown good success at inducing neutralizing antibody titers and appear to be a viable alternative to the conventional production of commercial clostridial toxoids. Research is still needed on the longevity of the humoral immune response induced by recombinant proteins in immunized animals, preferably in target species. The objective of this study was to measure the humoral immune response of cattle immunized with trivalent vaccines containing the recombinant proteins alpha (rCPA), beta (rCPB) and epsilon (rETX) of C. perfringens produced in Escherichia coli at three different concentrations (100, 200, and 400 µg) of each protein for 12 months. The recombinant vaccines containing 200 (RV2) and 400 µg (RV3) yielded statistically similar results at 56 days. They performed better throughout the study period because they induced higher neutralizing antibody titers and were detectable for up to 150 and 180 days, respectively. Regarding industrial-scale production, RV2 would be the most economical and viable formulation as it achieved results similar to RV3 at half the concentration of recombinant proteins in its formulation. However, none of the vaccines tested induced the production of detectable antibody titers on day 365 of the experiment, the time of revaccination typically recommended in vaccination protocols. Thus, reiterating the need for research in the field of vaccinology to achieve greater longevity of the humoral immune response against these clostridial toxins in animals, in addition to the need to discuss the vaccine schedules and protocols adopted in cattle production.

Keywords: antibody curve; biotechnology; immunology; recombinant alpha protein; recombinant beta protein; recombinant epsilon protein; serum neutralization; vaccine protocols.

Figure 1

Analysis of the mean titers of alpha (anti-CPA), beta (anti-CPB) and epsilon antitoxins (anti-ETX) of Clostridium perfringens in cattle immunized with the commercial vaccine (COMV) or with the recombinant trivalent vaccines (RV1, RV2, RV3) on day 56 after the first vaccination. Lowercase letters (a,b) were used to indicate whether the groups were statistically equal or different when compared by Dunn’s post hoc test (p < 0.05). The dashed lines show the minimum level of neutralizing antibody titers against each toxin required by law (4, 10 and 2 IU/mL for alpha, beta and epsilon, respectively). (A) Mean titers of neutralizing antibodies against CPA, (B) mean titers of neutralizing antibodies against CPB, and (C) mean titers of neutralizing antibodies against ETX.

Figure 2

(A) Mean titers of Clostridium perfringens alpha antitoxin (anti-CPA) in cattle immunized with the commercial vaccine (COMV) and cattle given the recombinant trivalent vaccines (RV1, RV2 and RV3) on days 56, 90, 120, 150 and 180 after the first vaccination. (B) Mean titers of Clostridium perfringens beta antitoxin (anti-CPB) in cattle immunized with the commercial vaccine (COMV) or a recombinant trivalent vaccine (RV1, RV2 and RV3) on days 56, 90, 120, 150 and 180 after the first vaccination. (C) Mean titers of Clostridium perfringens epsilon antitoxin (anti-ETX) in cattle immunized with commercial vaccine (COMV) or a recombinant trivalent vaccine (RV1, RV2 and RV3) on days 56, 90, 120, 150 and 180 after the first vaccination.