Duration of maternally derived immunity to tetanus and response in newborn foals given tetanus antitoxin.

The research paper investigates the duration of immunity in newborn foals against tetanus derived from their mothers, and their response to tetanus antitoxin (TAT) injections.

Study sample and timeline

• The study was conducted on a group of 30 newborn foals.
• The duration of the study was from birth to 4 months of age.

Testing for TAT Concentration

• At various times up to age 4 months, the researchers measured the serum tetanus antitoxin (TAT) concentrations in the foals.
• The measurements were taken at 1, 2, 3 and 4 months of age.

Results: Decreasing TAT levels over time

• In the first month of age, 5 out of 30 foals had serum titers less than 0.01 IU of TAT/ml.
• At the age of two months, 17 out of 28 foals showed TAT levels of less than 0.01 IU/ml.
• When the remaining foals reached three months, 22 out of 29 had TAT levels less than 0.01 IU/ml.
• Finally, when aged at 4 months, 24 out of 29 foals had TAT levels of less than 0.01 IU/ml.

Additional Immunity: Effect of TAT Injection

• The researchers found that administering TAT to newborn foals resulted in an immediate increase in their immunity, specifically in cases where circulating antitoxin levels were absent or minimal.
• Through testing, it was found that the immunity against tetanus provided by the TAT injections at birth lasted at least 3 months.

The overall conclusion of this research is that while maternal immunity to tetanus in foals decreases over time, supplementary TAT injections can boost immunity and provide protection for at least the first three months of life.