Related Experiment Videos
Abstract:
Model experiments in mice were used for the investigation of oral immunization against tetanus. The efficacy of oral tetanus toxoid application was tested by subcutaneous challenge (10 LD50 tetanus toxin) and antitoxin determination by L+-method. Reasonable protection could only be achieved when toxoid was in intensive contact with the mucous membranes of the oral cavity, whereas immunization by way of the gastrointestinal tract failed completely. After a single oral vaccination with 200 Lf fluid tetanus toxoid onto mucous membranes of the oral cavity the efficiency index was 75. A 100% protection was obtained in challenge after 3 applications of 200 Lf toxoid. In comparison, a single subcutaneous dose of 2 Lf tetanus toxoid resulted in an efficiency index of 100 and a single intranasal immunization with 100 Lf in an efficiency index of 93. Development of immunity after oral immunization was much accelerated if compared with parenteral immunization. 20% of the orally treated animals were immune 5 days after vaccination. After the same period subcutaneously treated animals had failed to develop any protection at all. Antitoxin titers after one oral vaccination (200 Lf) were similar to the ones after one subcutaneous dose (2 Lf). A distinct increase in antitoxin titers could only be observed when revaccination was done subcutaneously. The results obtained with mice apply analogically to guinea pigs.
Insights
Oral immunization with tetanus toxoid shows promise when applied directly to oral mucous membranes, offering rapid immunity. However, gastrointestinal administration proved ineffective in mouse and guinea pig models.
Area of Science:
- Immunology
- Vaccinology
- Preclinical Research
Background:
- Tetanus remains a significant public health concern, necessitating effective immunization strategies.
- Parenteral vaccination is the current standard, but alternative routes are being explored for improved accessibility and efficacy.
- Oral immunization presents a potential needle-free alternative, but its effectiveness against tetanus requires further investigation.
Purpose of the Study:
- To investigate the efficacy of oral immunization against tetanus using tetanus toxoid in animal models.
- To compare the protective immunity induced by oral administration with traditional parenteral (subcutaneous) and intranasal routes.
- To assess the speed of immunity development and antitoxin titers following oral tetanus toxoid vaccination.
Main Methods:
- Model experiments were conducted using mice and guinea pigs.
- Tetanus toxoid was administered orally, focusing on contact with oral mucous membranes and gastrointestinal tract.
- Efficacy was evaluated through subcutaneous challenge with tetanus toxin (10 LD50) and antitoxin level determination (L+-method).
Main Results:
- Oral immunization was effective only when tetanus toxoid had intensive contact with oral mucous membranes; gastrointestinal administration failed.
- A single oral vaccination (200 Lf) yielded a 75% efficiency index, while three applications achieved 100% protection.
- Oral immunization accelerated immunity development compared to subcutaneous routes, with 20% of animals showing immunity after 5 days versus 0% for subcutaneous.
Conclusions:
- Direct application of tetanus toxoid to oral mucous membranes is a viable strategy for inducing protective immunity.
- Oral immunization offers a faster onset of immunity compared to parenteral vaccination.
- Further research into optimizing oral tetanus toxoid delivery could lead to improved vaccination protocols.