A Clostridium botulinum type B vaccine for prevention of shaker foal syndrome.

The research paper discusses the development and testing of a vaccine, made from a chemically-inactivated toxin, to prevent Shaker Foal Syndrome, a fatal disease in horses caused by a bacterial toxin. The vaccine was found to induce immunity in horses, and it was also found that the immunity could be passed from a mother horse to her foal through nursing.

Vaccine Composition and Preparation

• The vaccine was created from a ‘toxoid’, a substance which has been derived from a toxin but rendered non-toxic, from the bacterium Clostridium botulinum type B. This was achieved by treating the toxin with 0.6% formalin for a period of 6 weeks.
• This toxoid was then absorbed onto aluminium hydroxide. Aluminium hydroxide is used in many vaccines as an adjuvant, a substance which enhances the body’s immune response to an antigen. This combined substance forms the basis of the vaccine.

Vaccine Testing for Safety and Immunogenicity

• The vaccine was tested for safety in guinea pigs, mice, and horses, to ensure that it did not cause any harmful effects. The specifics of the testing protocol and the results are not given in the abstract, so the full paper would need to be consulted for more detail.
• It was also tested for immunogenicity, or its ability to evoke an immune response, in both guinea pigs and horses. Again, the details of these tests and the results would be in the full paper.

Immunisation and Protection

• Neutralising antitoxin, an antibody with the ability to counteract the specific toxin, was found in adult horses after receiving two subcutaneous (under the skin) doses of the vaccine administered 6 weeks apart.
• A foal was also found to have these antibodies after it nursed from its vaccinated mother, showing that immunity can be passed on to offspring through nursing.
• Another horse and a passively immunised foal (i.e., a foal that received immunity through its mother’s milk rather than through direct vaccination) were protected against a large dose of toxin. These results suggest that the vaccine can provide effective safeguard against the toxin in horses.