Alternative vaccination against equine botulism (BoNT/C).

The research article investigates whether a recombinant vaccine could be an effective preventative measure against botulism in horses. The study finds that the vaccine is capable of stimulating an immunity response that produces neutralising antibodies, and causes fewer adverse reactions compared to commercially available vaccines.

Research Objective

• The main aim of the research was to determine the efficacy of a recombinant vaccine against botulism in horses. The researchers specifically wanted to find out whether the C-terminal half of the heavy chain of the botulinum neurotoxin C (Hc BoNT/C), when combined with an adjuvant to stimulate the immune response, could prove effective in preventing botulism in horses, especially against the backdrop of the increased incidence of the disease in Europe’s horse population.

Methodology

• The study team compared the results from the recombinant vaccine with those of a commercial toxoid vaccine, in terms of immune response, adverse reactions, and other key parameters.
• They used ELISA and Western blot testing against Hc BoNT/C and also conducted tests for the induction of neutralising antibodies via a mouse protection assay.
• The team monitored the formation of oedema and local pain reactions as part of assessing the overall reactions to the vaccines.

Results

• The findings indicate that horses vaccinated with the recombinant version experienced only minor local swelling, with complete recovery within five days. The commercial toxoid vaccine, on the other hand, induced local painful reactions and required longer recovery periods of up to two weeks.
• Vaccinated horses induced neutralising antibodies after the second booster injection, for both the recombinant and toxoid vaccines. The seroconversion to Hc BoNT/C was apparent after the first dose of the recombinant vaccine and at diverse time points for horses that received the commercial toxoid vaccine.
• Fundraimentally, there was no correlation between the serological response to Hc BoNT/C and the neutralising ability of the serum.

Conclusions

• The study established that the recombinant vaccine not only showed fewer adverse reactions compared to the available commercial vaccine but also induced similar levels of neutralising antibodies.
• Therefore, it found that the recombinant Hc BoNT/C is a suitable vaccine candidate that can stimulate the production of neutralising antibodies against botulinum neurotoxin C in horses. The vaccine also induced only minor local reactions at the injection site making it a potentially safer alternative.