Evaluating the Biochemical and Haematological Safety of the Histoplasma capsulatum var. farciminosum ‘8ZH’ Vaccine in Foals

Q: What disease and pathogen does this study focus on?

The study focuses on epizootic lymphangitis (EEL), caused by Histoplasma capsulatum var. farciminosum (HCF).

Q: How was the ‘8ZH’ vaccine administered and what groups were used?

Thirty healthy foals were randomized into vaccinated (n=15) and control (n=15) groups. Vaccinated foals received 5 mL intramuscularly with a booster on Day 21, while controls received 5 mL sterile saline under identical conditions.

Q: What safety findings were observed after vaccination?

No severe or adverse reactions occurred. Mild, transient injection-site swelling (<4 cm) appeared in three vaccinated foals and resolved spontaneously, with most measured biochemical and acute-phase protein parameters staying within physiological limits.

Sep 30, 2026

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Epizootic lymphangitis (EEL), caused by Histoplasma capsulatum var. farciminosum, remains a neglected equine fungal disease without effective vaccines. This study evaluates the biochemical, haematological, and clinical safety of an inactivated HCF ‘8ZH’ vaccine in foals. A controlled, single-blinded trial followed 30 healthy foals randomized to vaccinated and control groups, with clinical monitoring and serial blood sampling for biochemical and acute-phase protein analyses. Vaccination produced only mild, transient local swelling and no long-term toxic or statistically significant adverse effects.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages8

Reading Time20 min

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Abstract

Background and Objectives

Methods

Results

Conclusions

Introduction

Methods

Study Design

Veterinary Medicine and Science ORIGINAL ARTICLE Equine Evaluating the Biochemical and Haematological Safety of the Histoplasma capsulatum var. farciminosum ‘8ZH’Vaccine in Foals Sabira E. Alpysbayeva1 Akbope A. Abdykalyk1 Kali Tileukhanov2 Azamat R. Abdimukhtar1 Alinur T. Toleukhan1 Makhpal K. Sarmykova1 Aktoty M. Anarbekova1 Yeraly A. Shayakhmetov1 Nazym S. Syrym1 Sergazy Sh. Nurabaev1 Bolat A. Yespembetov1 1 Research Institute for Biological Safety Problems, National Holding “QazBioPharm, Otar, Kazakhstan 2Al-Farabi Kazakh National University, Almaty, Kazakhstan Correspondence: Bolat A. Yespembetov ([b.yespembetov@biosafety.kz](b.yespembetov@biosafety.kz)) Received: 28 March 2025 Revised: 22 July 2025 Accepted: 11 December 2025 Keywords: biochemical markers | biochemical parameters | epizootic lymphangitis | equine vaccine | foals | histoplasma farciminosum | histoplasma capsulatum var. farciminosum | vaccine safety ABSTRACT Background: Epizootic lymphangitis (EEL), caused by Histoplasma capsulatum var. farciminosum (HCF), is a neglected equine fungal disease lacking effective vaccines. The newly developed inactivated ‘8ZH’ vaccine requires safety validation in the target species. Objectives: To evaluate the biochemical, haematological and clinical safety of the inactivated HCF ‘8ZH’ vaccine in foals. Methods: A controlled, single-blinded study was conducted on 30 clinically healthy foals (4–6 months), randomized into vaccinated (n = 15) and control (n = 15) groups. Vaccinated animals received a 5 mL intramuscular dose (10 mg antigen, MONTANIDE GEL 01 PR adjuvant) on Day 0 and a booster on Day 21. Clinical observations (temperature, appetite, behaviour, injection site) were recorded daily. Blood was collected at baseline and on Days 7, 14, 21, 35 and 42 for biochemical, haematological and acute-phase protein analysis. Data were analysed using repeated measures ANOVA. Results: No severe or adverse reactions were observed. Mild, transient injection-site swelling (<4 cm) occurred in three vaccinated foals and resolved spontaneously. All animals maintained normal temperature and appetite. AST showed a transient increase on Day 14 (p = 0.04); WBC also rose (p = 0.03), indicating a typical immune response. Other parameters, including ALT, GGT, creatinine, total bilirubin and acute-phase proteins (SAA, fibrinogen, haptoglobin), remained within physiological limits. No statistically significant long-term deviations or toxic effects were noted. Conclusions: The inactivated HCF ‘8ZH’ vaccine demonstrated a favourable safety profile in foals. These results support its continued development for use in EEL prevention programs. 1 Introduction Epizootic lymphangitis (EEL) is a chronic and highly contagious fungal disease in equines, caused by Histoplasma capsulatum var. farciminosum (HCF), a thermally dimorphic variety of Histoplasma capsulatum (Ameni 2007) . The disease predominantly impacts horses, although donkeys and mules exhibit enhanced resistance (Selim et al. 1985; Al-Ani and AlDelaimi 1986). EEL is characterized by granulomatous lesions in the lymphatic vessels, skin and lungs, posing significant risks to This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2026 The Author(s) . Veterinary Medicine and Science published by John Wiley & Sons Ltd. Veterinary Medicine and Science, 2026; 12:e70764 1 of 8 [https://doi.org/10.1002/vms3.70764](https://doi.org/10.1002/vms3.70764) equine health, productivity and welfare, especially in areas with limited veterinary access (Scantlebury & Reed, 2009) . The disease persists as endemic in various African countries (Ethiopia, Nigeria, Sudan, Senegal, South Africa) (Abdela et al. 2021; Ameni 2006; Addo 1980; Abdullahi et al. 2019; Awad 1960), the Middle East (Egypt, Iraq) (Hamid a

FAQs

What disease and pathogen does this study focus on?

The study focuses on epizootic lymphangitis (EEL), caused by Histoplasma capsulatum var. farciminosum (HCF).

How was the ‘8ZH’ vaccine administered and what groups were used?

Thirty healthy foals were randomized into vaccinated (n=15) and control (n=15) groups. Vaccinated foals received 5 mL intramuscularly with a booster on Day 21, while controls received 5 mL sterile saline under identical conditions.

What safety findings were observed after vaccination?

No severe or adverse reactions occurred. Mild, transient injection-site swelling (<4 cm) appeared in three vaccinated foals and resolved spontaneously, with most measured biochemical and acute-phase protein parameters staying within physiological limits.

Sep 30, 2026

Uploaded by kopisore