FREE SHIPPING over $40
OVER 10000 FIVE-STAR REVIEWS
5% OFF ALL SUBSCRIPTIONS
100% HAPPINESS GUARANTEE
Analyze Diet
0
Equine veterinary journal2026; doi: 10.1002/evj.70303

Antibody kinetics against tetanus toxoid before and after primary vaccination of foals.

Abstract: Vaccination recommendations for foals against Clostridium tetani vary. Available studies assessing foal immune responses, maternal antibody interference, or individual variation often used small foal numbers. Objective: To quantify antibody responses after tetanus vaccination in foals and explore associations with passively transferred tetanus antibodies. Methods: Longitudinal cohort study. Methods: Sixty-two Warmblood foals from a single stud farm were followed from birth to 360 days of age. Foals received tetanus vaccinations at day 180 (d180) and d220 of life. Serum samples were collected at 19 time points during the study period and analysed using a fluorescent bead-based Tetanus Multiplex assay to quantify total and isotype-specific anti-tetanus antibodies. Results: Passively transferred anti-tetanus antibodies in foal serum started to decline on d15 until d180. The first tetanus vaccination on d180 did not induce detectable antibodies. Following the second vaccination on d220, antibodies peaked on d230, before declining again to concentrations below pre-vaccination by d360. A weak correlation was observed between maternally derived antibodies on d5 and the vaccine-induced response on d230 (r = -0.36). Antibodies between pre- (d180) and post-vaccination (d230) did not correlate (r = -0.16). IgG1 contributed majorly to the initial vaccine-induced response, whereas IgM remained unaffected. The individual variability in antibody responses was high, with 38.7% of the foals showing low responsiveness to vaccination. Conclusions: Only foals from a single farm were included; only one vaccine and tetanus vaccination schedule were evaluated, and a nonvaccinated control group or foals without maternal antibodies were not available. Conclusions: The variability in foal responses and the rapid post-vaccination antibody decline suggest that tetanus vaccination schedules for foals, including booster timing, may benefit from optimisation. Low vaccine responses at a time when passively transferred antibody concentrations had waned challenges the hypothesis of maternal antibodies as the sole reason for reduced antibody induction in foals.
© 2026 The Author(s). Equine Veterinary Journal published by John Wiley & Sons Ltd on behalf of EVJ Ltd.
Get Full Text
Publication Date: 2026-08-09 PubMed ID: 42572177DOI: 10.1002/evj.70303Google Scholar: Lookup
The Equine Research Bank provides access to a large database of publicly available scientific literature. Inclusion in the Research Bank does not imply endorsement of study methods or findings by Mad Barn.
LinkedInCopy
  • Journal Article

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

Overview

  • This study investigated how foals’ antibody levels against tetanus toxoid change before and after primary vaccination, examining the role of maternal antibodies and individual variation in immune response.
  • The research aimed to evaluate the effectiveness of a tetanus vaccination schedule in foals and assess whether maternal antibodies interfere with vaccine-induced immunity.

Background and Purpose

  • Tetanus vaccination protocols for foals vary widely, and existing studies often use small sample sizes, limiting generalizability.
  • Foals receive some immunity through maternal antibodies transferred passively but these may interfere with the foal’s own immune response to vaccination.
  • This study aimed to quantify the antibody responses generated by tetanus vaccination in a larger cohort of foals and explore the relationship between those responses and the presence of maternally derived antibodies.

Study Design and Methods

  • Prospective longitudinal cohort study involving 62 Warmblood foals from a single stud farm.
  • Foals were followed from birth until 360 days of age.
  • Tetanus vaccinations were administered at day 180 and day 220 of life.
  • Serum samples were collected at 19 different time points across the study period to measure anti-tetanus antibody levels.
  • The Tetanus Multiplex assay, a fluorescent bead–based method, was used to quantify total antibodies and specific antibody isotypes (IgG1 and IgM) against tetanus toxoid.

Key Findings

  • Maternal antibodies against tetanus were detectable at birth but began to decline starting from day 15 and continued falling until day 180.
  • The first tetanus vaccination at day 180 did not induce detectable levels of new antibodies, indicating low immune activation at that time.
  • After the second vaccination at day 220, antibody levels peaked around day 230.
  • These post-vaccination antibody levels then declined, falling below the levels seen before vaccination by day 360.
  • There was a weak negative correlation (r = -0.36) between maternally derived antibody levels on day 5 and the vaccine-induced antibody response at day 230, suggesting that higher maternal antibodies might slightly dampen vaccine response but not strongly.
  • No significant correlation (r = -0.16) was found between antibody levels immediately before vaccination (day 180) and after vaccination (day 230), indicating preexisting antibody levels did not predict vaccine response.
  • The primary vaccine-induced antibody response was driven mainly by the IgG1 isotype, while IgM levels remained essentially unchanged.
  • Considerable individual variation was observed in vaccine response intensity, with about 38.7% of foals showing a low response to vaccination.

Interpretation and Implications

  • The rapid decline in maternally derived antibodies prior to vaccination suggests a limited window of passive immunity in foals.
  • The first vaccination at day 180 was insufficient to stimulate measurable active immunity, whereas the second at day 220 was required for a peak immune response.
  • The decline of antibodies below pre-vaccination concentrations after several months indicates the vaccine-induced immunity may be short-lived without boosters.
  • Since many foals showed low responsiveness even when maternal antibodies had waned, other factors beyond maternal antibody interference may contribute to low vaccine efficacy, challenging the assumption that maternal antibodies alone suppress immunization.
  • The wide inter-individual variability points to a need for personalized or optimized vaccination schedules rather than one-size-fits-all protocols.

Limitations

  • All foals studied came from a single farm, possibly limiting the external validity across breeds, environments, or management conditions.
  • Only one vaccine type and schedule (vaccinations at day 180 and 220) were tested; other vaccines or timing regimens were not evaluated.
  • Lack of a nonvaccinated control group or foals without maternal antibodies reduced the ability to directly assess the maternal antibody impact or natural antibody decay unrelated to vaccination.

Conclusions

  • The study suggests that foal tetanus vaccination protocols may need optimization, especially regarding the timing of boosters, to maintain effective immunity.
  • Findings question the notion that maternal antibody interference is the sole factor limiting vaccine response in foals.
  • More comprehensive studies with varied vaccines, schedules, and populations are needed to refine vaccination strategies for better protection of foals against tetanus.

Cite This Article

APA
Olbrich K, Venner M, Wagner B. (2026). Antibody kinetics against tetanus toxoid before and after primary vaccination of foals. Equine Vet J. https://doi.org/10.1002/evj.70303

Publication

Equine veterinary journal
ISSN: 2042-3306
NlmUniqueID: 0173320
Country: United States
Language: English

Researcher Affiliations

Olbrich, Katharina
  • Clinic for Horses, University of Veterinary Medicine, Hanover, Hanover, Germany.
Venner, Monica
  • Equine Clinic Destedt, Destedt, Germany.
Wagner, Bettina
  • Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.

Grant Funding

  • Gesellschaft für Pferdemedizin e. V.

References

This article includes 52 references
  1. Almas T, Niaz MA, Zaidi SMJ, Haroon M, Khedro T, Alsufyani R. The spectrum of clinical characteristics and complications of tetanus: a retrospective cross‐sectional study from a developing nation.. Cureus 2021;13(6):e15484.
  2. Cook TM, Protheroe RT, Handel JM. Tetanus: a review of the literature.. Br J Anaesth 2001;87(3):477–487.
  3. Bohnert S, Schiavo G. Tetanus toxin is transported in a novel neuronal compartment characterized by a specialized pH regulation.. J Biol Chem 2005;280(51):42336–42344.
  4. Kendall A, Anagrius K, Gånheim A, Rosanowski SM, Bergström K. Duration of tetanus immunoglobulin G titres following basic immunisation of horses.. Equine Vet J 2016;48(6):710–713.
  5. Ribeiro MG, Nardi Júnior GD, Megid J, Franco MMJ, Guerra ST, Portilho FVR. Tetanus in horses: an overview of 70 cases.. Pesqui Vet Bras 2018;38(2):285–293.
  6. Green SL, Little CB, Baird JD, Tremblay RRM, Smith‐Maxie LL. Tetanus in the horse: a review of 20 cases (1970 to 1990).. J Vet Intern Med 1994;8(2):128–132.
  7. Van Galen G, Delguste C, Sandersen C, Verwilghen D, Grulke S, Amory H. Tetanus in the equine species: a retrospective study of 31 cases.. Tijdschr Diergeneeskd 2008;133(12):512–517.
  8. Van Galen G, Saegerman C, Rijckaert J, Amory H, Armengou L, Bezdekova B. Retrospective evaluation of 155 adult equids and 21 foals with tetanus in Western, northern, and Central Europe (2000–2014). Part 1: description of history and clinical evolution.. J Vet Emerg Crit Care 2017;27(6):684–696.
  9. StIKo Vet am FLI. Leitlinie zur Impfung von Pferden—5. Auflage [Stand 06.01.2025].. Tierarztl Prax Ausg G Grosstiere Nutztiere 2025;53(1):33–38.
  10. AAEP. Core vaccination guidelines: tetanus.. Lexington, KY: American Association of Equine Practitioners; 2021.
  11. Ryan C, Giguère S. Equine neonates have attenuated humoral and cell‐mediated immune responses to a killed adjuvanted vaccine compared to adult horses.. Clin Vaccine Immunol 2010;17(12):1896–1902.
  12. Wilson WD. Vaccination Programs for Foals and Weanlings.. Proc Am Ass Equine Practnrs 1999;45:254–263.
  13. Wagner B, Burton A, Ainsworth D. Interferon‐gamma, interleukin‐4 and interleukin‐10 production by T helper cells reveals intact Th1 and regulatory TR 1 cell activation and a delay of the Th2 cell response in equine neonates and foals.. Vet Res 2010;41(4):47.
  14. Perkins GA, Wagner B. The development of equine immunity: current knowledge on immunology in the young horse.. Equine Vet J 2015;47(3):267–274.
  15. Jeffcott LB. Some practical aspects of the transfer of passive immunity to newborn foals.. Equine Vet J 1974;6(3):109–115.
  16. Jansen BC, Knoetze PC. The immune response of horses to tetanus toxoid.. Onderstepoort J Vet Res 1979;46(4):211–216.
  17. Liu IK, Brown SL, Kuo J, Neeley DP, Feeley JC. Duration of maternally derived immunity to tetanus and response in newborn foals given tetanus antitoxin.. Am J Vet Res 1982;43(11):2019–2022.
  18. Liefman CE. Active immunisation of horses against tetanus including the booster dose and its application.. Aust Vet J 1981;57(2):57–60.
  19. Liefman CE. Combined active‐passive immunisation of horses against tetanus.. Aust Vet J 1980;56(3):119–122.
  20. Gildea S, Sanchez Higgins MJ, Johnson G, Walsh C, Cullinane A. Concurrent vaccination against equine influenza and equine herpesvirus—a practical approach.. Influenza Other Respi Viruses 2016;10(5):433–437.
  21. Wagner B, Glaser A, Hillegas JM, Erb H, Gold C, Freer H. Monoclonal antibodies to equine IgM improve the sensitivity of West Nile virus‐specific IgM detection in horses.. Vet Immunol Immunopathol 2008;122(1):46–56.
  22. Sheoran AS, Lunn DP, Holmes MA. Monoclonal antibodies to subclass‐specific antigenic determinants on equine immunoglobulin gamma chains and their characterization.. Vet Immunol Immunopathol 1998;62(2):153–165.
  23. Keggan A, Freer H, Rollins A, Wagner B. Production of seven monoclonal equine immunoglobulins isotyped by multiplex analysis.. Vet Immunol Immunopathol 2013;153(3–4):187–193.
  24. Heldens JGM, Kersten AJ, Weststrate MW, Van Den Hoven R. Vaccinology: duration of immunity induced by an adjuvanted and inactivated equine influenza, tetanus and equine herpesvirus 1 and 4 combination vaccine.. Vet Q 2001;23(4):210–217.
  25. Wilson WD, Mihalyi JE, Hussey S, Lunn DP. Passive transfer of maternal immunoglobulin isotype antibodies against tetanus and influenza and their effect on the response of foals to vaccination.. Equine Vet J 2001;33(7):644–650.
  26. Gallacher K, Champion K, Denholm KS. Mare colostrum quality and relationship with foal serum immunoglobulin G concentrations and average daily weight gains.. Equine Vet J 2025;57(4):904–914.
  27. Rampacci E, Mazzola K, Beccati F, Passamonti F. Diagnostic characteristics of refractometry cut‐off points for the estimation of immunoglobulin G concentration in mare colostrum.. Equine Vet J 2023;55(1):102–110.
  28. Sobral GGD, Neto OCG, Da Silva AM, Carneiro GF. Evaluation of optical refractometer for assessing failure of transfer of passive immunity in foals.. J Equine Vet Sci 2021;106:103758.
  29. Erhard MH, Luft C, Remler H‐P, Stangassinger M. Assessment of colostral transfer and systemic availability of immunoglobulin G in new‐born foals using a newly developed enzyme‐linked immunosorbent assay (ELISA) system.. J Anim Physiol Anim Nutr 2001;85(5–6):164–173.
  30. Franco Ayala MS, Oliver‐Espinosa OJ. Risk factors associated with failure of passive transfer of Colostral immunoglobulins in neonatal paso Fino foals.. J Equine Vet Sci 2016;44:100–104.
  31. Kalinbacak A, Guzel M, Altıntaş I. Incidence of failure of immune passive transfer (FPT) in thoroughbred foals: Interest of a rapid diagnosis for FPT. Rev Med Vet 2005;156:163–165.
  32. Van Maanen C, Bruin G, De Boer‐Luijtze E, Smolders G, De Boer GF. Interference of maternal antibodies with the immune response of foals after vaccination against equine influenza. Vet Q 1992;14(1):13–17.
  33. Heldens JGM, Pouwels HGW, Derks CGG, Van De Zande SMA, Hoeijmakers MJH. Duration of immunity induced by an equine influenza and tetanus combination vaccine formulation adjuvanted with ISCOM‐matrix. Vaccine 2010;28(43):6989–6996.
  34. Scheibel I. The uses and results of active tetanus immunization. Bull World Health Organ 1955;13(3):381–394.
  35. Desanti‐Consoli H, Bouillon J, Chapuis RJJ. Equids' core vaccines guidelines in North America: considerations and prospective. Vaccines (Basel) 2022;10(3):398.
  36. Löhrer J, Radvila P. Aktive Tetanusprophylaxe beim Pferd und Immunitätsdauer. 1970.
  37. Borella‐Venturini M, Frasson C, Paluan F, De Nuzzo D, Di Masi G, Giraldo M. Tetanus vaccination, antibody persistence and decennial booster: a serosurvey of university students and at‐risk workers. Epidemiol Infect 2017;145(9):1757–1762.
  38. Tharu B, Ibrahim S, Shah M, Basnet S, Park T. An unusual case of evolving localized tetanus despite prior immunization and protective antibody titer. Cureus 2020;12(7):e9498.
  39. Vollman KE, Acquisto NM, Bodkin RP. A case of tetanus infection in an adult with a protective tetanus antibody level. Am J Emerg Med 2014;32(4):392.e3–392.e4.
  40. Wagner B, Freer H, Rollins A, Erb HN, Lu Z, Gröhn Y. Development of a multiplex assay for the detection of antibodies to Borrelia burgdorferi in horses and its validation using Bayesian and conventional statistical methods. Vet Immunol Immunopathol 2011;144(3–4):374–381.
  41. Goodman LB, Wimer C, Dubovi EJ, Gold C, Wagner B. Immunological correlates of vaccination and infection for equine herpesvirus 1. Clin Vaccine Immunol 2012;19(2):235–241.
  42. Guarino C, Franklin‐Guild R, Asbie S, Pinn‐Woodcock T, Sipka AS, Eade C. A fluorescent bead‐based multiplex assay for the detection of Brucella sp. specific antibodies in canine serum. Front Microbiol 2025;16:1655877.
  43. Sipka A, Wagner B. Fluorescent bead‐based multiplex assays improve serological disease diagnostics and have potential of identifying sensitive immune biomarkers for maintaining health and performance. J Am Vet Med Assoc 2025;263(S1):S33–S44.
  44. Perkins G, Babasyan S, Stout AE, Freer H, Rollins A, Wimer CL. Intranasal IgG4/7 antibody responses protect horses against equid herpesvirus‐1 (EHV‐1) infection including nasal virus shedding and cell‐associated viremia. Virology 2019;531:219–232.
  45. Schnabel CL, Babasyan S, Rollins A, Freer H, Wimer CL, Perkins GA. An equine herpesvirus type 1 (EHV‐1) Ab4 open reading frame 2 deletion mutant provides immunity and protection from EHV‐1 infection and disease. J Virol 2019;93(22):e01011‐19.
  46. Thein P, Röhm JA, Voss J. Experimental investigations to the immune response of foals and adult horses to tetanus toxoid using the Fassisi TetaCheck®. Pferdeheilkunde. Equine Med 2013;29(6):686–699.
  47. Davis EG, Bello NM, Bryan AJ, Hankins K, Wilkerson M. Characterisation of immune responses in healthy foals when a multivalent vaccine protocol was initiated at age 90 or 180 days. Equine Vet J 2015;47(6):667–674.
  48. Flaminio MJBF, Nydam DV, Marquis H, Matychak MB, Giguère S. Foal monocyte‐derived dendritic cells become activated upon Rhodococcus equi infection. Clin Vaccine Immunol 2009;16(2):176–183.
  49. Mérant C, Breathnach CC, Kohler K, Rashid C, Van Meter P, Horohov DW. Young foal and adult horse monocyte‐derived dendritic cells differ by their degree of phenotypic maturity. Vet Immunol Immunopathol 2009;131(1–2):1–8.
  50. Breathnach CC, Sturgill‐Wright T, Stiltner JL, Adams AA, Lunn DP, Horohov DW. Foals are interferon gamma‐deficient at birth. Vet Immunol Immunopathol 2006;112(3–4):199–209.
  51. Wagner B, Stokol T, Ainsworth DM. Induction of interleukin‐4 production in neonatal IgE+ cells after crosslinking of maternal IgE. Dev Comp Immunol 2010;34(4):436–444.
  52. Wagner B, Perkins G, Babasyan S, Freer H, Keggan A, Goodman LB. Neonatal immunization with a single IL‐4/antigen dose induces increased antibody responses after challenge infection with equine herpesvirus type 1 (EHV‐1) at weanling age. PLoS One 2017;12(1):e0169072.

Citations

This article has been cited 0 times.
Subscribe to our newsletter
Join 106,294 horse owners like you who receive our email updates on horse health and nutrition.