Botulinum neurotoxins (BoNTs) are among the most dangerous proteins. Vaccination is an excellent botulism prevention method. A recombinant non-His-tagged version of the Hc domain of botulinum neurotoxin serotype E (rEHc) was produced in Escherichia coli and purified by sequential chromatography to provide a vaccine appropriate for human usage. In mice, the immunogenicity of rEHc was investigated, and both antibody titers and protective efficacy were found to be dose- and time-dependent. Then, rEHc was expressed and purified on a pilot scale, and its immunological activity was assessed. Findings indicate that rEHc has high immunogenicity and may elicit substantial protective potency against botulinum neurotoxin serotype E (BoNT/E) in mice, indicating that rEHc is a viable botulism vaccine candidate. Furthermore, by extracting F(ab)2 from pepsin-digested serum IgG of rEHc-inoculated horses, researchers created a new antitoxin against BoNT/E. The antitoxin F(ab)2 was tested in vitro and in vivo for its protective effect. The findings showed that F(ab)2 antitoxin may successfully prevent botulism in BoNT/E-challenged mice and significantly reduce the development of paralysis induced by BoNT/E to achieve therapeutic benefits.

As a result, our findings provide useful experimental data for the development of a new antitoxin that might be used to treat BoNT/E-induced botulism.