Anawach Phuengkasem Regional Technical Manager, Southeast Asia PATENT CO DOO. Misicevo, Serbia. As the global demand for pork increases, pig farming has become more intensive. This means that farmers need to rely heavily on vaccines to control diseases and prevent major financial losses. However, sometimes, even with a perfect vaccination schedule, vaccines do not work as expected. While many factors can affect a vaccine’s effectiveness, those that weaken a pig’s immune system are a major reason why an otherwise good vaccine might fail to protect the animal (Augustyniak y Pomorska-Mól, 2023). A vaccine can fail for several reasons... Sometimes, the issue lies with the vaccine itself—such as being stored at the wrong temperature or administered incorrectly. Other times, the problem is related to the pig, including factors like age, genetics, or diet. However, a particularly serious concern arises when something actively suppresses the pig’s immune system, making it unable to build protection even with a wellformulated vaccine (Augustyniak y Pomorska-Mól, 2023). THE HIDDEN CHALLENGE: MYCOTOXINS Mycotoxins are a natural defense mechanism produced by certain types of molds—such as Aspergillus, Fusarium and Penicillium, which are common in agricultural settings. These mycotoxins—including aflatoxins (AF), deoxynivalenol (DON), zearalenone (ZEN), fumonisins (FB), and ochratoxin A (OTA)- can develop on crops in the field or during feed storage (Bulgaru et al., 2021). While consuming a large dose of mycotoxins can make a pig visibly sick, a more frequent and costly problem arises from the ingestion of low levels of these toxins over a prolonged period. HOW DO MYCOTOXINS WEAKEN THE IMMUNE SYSTEM? A healthy immune system is a dynamic network of cells that are constantly working and replicating to protect the body. ⇒This continuous activity makes it particularly vulnerable to toxins that interfere with fundamental cellular functions. General mechanisms of immune disruption Mycotoxins impair the immune system through several interconnected pathways: Specific consequences for immune function These mechanisms result in functional impairments across various components of the immune system. WHEN PROTECTION IS DISRUPTED: THE LINK TO VACCINATION When a pig’s immune system is weakened, it is no surprise that vaccines cannot perform their role effectively. Mycotoxins interfere with this learning process at every stage (Augustyniak y Pomorska-Mól, 2023). Why vaccinations may be less effective with mycotoxins There is a wide array of mycotoxin-induced effects on the immune system can lead to vaccination failure. Clinical signs of reduced vaccination efficacy At the farm level, this issue may manifest as multiple production challenges: STRATEGIES FOR RESTORING BALANCE AND ENHANCING PROTECTION Protecting the investment in vaccination requires an integrated and proactive approach to mycotoxin risk management. In conclusion, the correlation between dietary mycotoxin contamination and vaccination failure is a critical concern for swine production. References Augustyniak, A., & Pomorska-Mól, M. (2023). Vaccination Failures in Pigs—The Impact of Chosen Factors on the Immunisation Efficacy.Vaccines. https://doi.org/10.3390/vaccines11020230 Bracarense, A.-P. F. L., Lucioli, J., Grenier, B., Pacheco, G. D., Moll, W.-D., Schatzmayr, G., & Oswald, I. P. (2011). Chronic ingestion of deoxynivalenol and fumonisin, alone or in interaction, induces morphological and immunological changes in the intestine of piglets.British Journal of Nutrition. https://doi.org/10.1017/S0007114511004946 Bulgaru, C. V., Marin, D. E., Pistol, G. C., & Taranu, I. (2021). Zearalenone and the Immune Response.Toxins. https://doi.org/10.3390/toxins13040248 Burel, C., Tanguy, M., Guerre, P., Boilletot, E., Cariolet, R., Queguiner, M., Postollec, G., Pinton, P., Salvat, G., Oswald, I. P., & Fravalo, P. (2013). Effect of Low Dose of Fumonisins on Pig Health: Immune Status, Intestinal Microbiota and Sensitivity to Salmonella.Toxins. https://doi.org/10.3390/toxins5040841 Chen, F., Ma, Y., Xue, C., Ma, J., Xie, Q., Wang, G., Bi, Y., & Cao, Y. (2008). The combination of deoxynivalenol and zearalenone at permitted feed concentrations causes serious physiological effects in young pigs.Journal of Veterinary Science. Lafleur Larivière, É., Zhu, C., Sharma, A., Karrow, N. A., & Huber, L.-A. (2022). The effects of deoxynivalenol-contaminated corn in low-complexity diets supplemented with either an immune-modulating feed additive, or fish oil on nursery pig growth performance, immune response, small intestinal morphology, and component digestibility. Translational Animal Science. https://doi.org/10.1093/tas/txac068 Liu, X., Xu, C., Yang, Z., Yang, W., Huang, L., Wang, S., Liu, F., Liu, M., Wang, Y., & Jiang, S. (2020). Effects of Dietary Zearalenone Exposure on the Growth Performance, Small Intestine Disaccharidase, and Antioxidant Activities of Weaned Gilts.Animals. https://doi.org/10.3390/ani10112157 Oswald, I. P., Marin, D. E., Bouhet, S., Pinton, P., Taranu, I., & Accensi, F. (2005a). Immunotoxicological risk of mycotoxins for domestic animals.Food Additives and Contaminants. https://doi.org/10.1080/02652030500058320 Pierron, A., Alassane-Kpembi, I., & Oswald, I. P. (2016). Impact of mycotoxin on immune response and consequences for pig health.Animal Nutrition. https://doi.org/10.1016/j.aninu.2016.03.001 Pistol, G. C., Gras, M. A., Marin, D. E., Israel-Roming, F., Stancu, M., & Taranu, I. (2013). Natural feed contaminant zearalenone decreases the expressions of important pro- and anti-inflammatory mediators and mitogen-activated protein kinase/NF-kB signalling molecules in pigs.British Journal of Nutrition. https://doi.org/10.1017/S0007114513002675 Rückner, A., Plagge, L., Heenemann, K., Harzer, M., Thaa, B., Winkler, J., Dänicke, S., Kauffold, J., & Vahlenkamp, T. W. (2022). The mycotoxin deoxynivalenol (DON) can deteriorate vaccination efficacy against porcine reproductive and respiratory syndrome virus (PRRSV) at subtoxic levels.Porcine Health Management. https://doi.org/10.1186/s40813-022-00254-1 Thapa, A., Horgan, K. A., White, B., & Walls, D. (2021). Deoxynivalenol and Zearalenone - Synergistic or Antagonistic Agri-Food Chain Co-Contaminants?Toxins. https://doi.org/10.3390/toxins13080561
E-mail: [email protected]
Understanding why these failures occur is critical for farmers who constantly face threats from swine diseases.
Mold contamination is a global problem: the Food and Agriculture Organization (FAO) estimates that at least 25 % of the world’s crops are affected each year (Thapa et al., 2021; Bracarense et al., 2011).
At such levels, mycotoxins weaken the immune system.
The purpose of vaccination is to train a healthy immune system to recognize a pathogen and remember how to fight it.
The goal is to minimize exposure to these toxins while supporting the animal’s natural resilience, thereby creating conditions in which vaccines can achieve their full effectiveness.
Mycotoxins can weaken immunity and compromise the protection normally provided by vaccines.
18/09/25
Mycotoxins in swine: Overlooked driver of vaccination failure
In pigs, exposure to mycotoxins can reduce vaccine efficacy by interfering with the activation of the immune system.
One of the most common—and often overlooked—causes of this immune suppression is hidden in the animal’s daily feed: mycotoxins.
This immune impairment reduces pigs’ resistance to disease, slows their growth and productivity, and—most importantly—undermines the very health programs designed to protect them, such as vaccination (Pierron et al., 2016; Oswald et al., 2005).
Mycotoxins exploit this vulnerability to disrupt the animal’s natural defenses (Pierron et al., 2016; Oswald et al., 2005).
By recognizing this risk and implementing a comprehensive management strategy, farmers can safeguard animal health and ensure that vaccination programs achieve their intended effectiveness.
Micotoxicosis prevention