The mycotoxin deoxynivalenol (DON) can deteriorate vaccination efficacy against porcine reproductive and respiratory syndrome virus (PRRSV) at subtoxic levels

Antje Rückner; Lisa Plagge; Kristin Heenemann; Maxi Harzer; Bastian Thaa; Janine Winkler; Sven Dänicke; Johannes Kauffold; Thomas W Vahlenkamp

doi:10.1186/s40813-022-00254-1

The mycotoxin deoxynivalenol (DON) can deteriorate vaccination efficacy against porcine reproductive and respiratory syndrome virus (PRRSV) at subtoxic levels

Porcine Health Manag. 2022 Mar 20;8(1):13. doi: 10.1186/s40813-022-00254-1.

Authors

Affiliations

¹ Centre for Infectious Diseases, Institute of Virology, Faculty of Veterinary Medicine, University of Leipzig, An den Tierkliniken 29, 04103, Leipzig, Germany.
² Institute of Animal Nutrition, Friedrich Loeffler Institute, Federal Research Institute for Animal Health, Brunswick, Germany.
³ Clinic for Ruminants and Swine, Faculty of Veterinary Medicine, University of Leipzig, Leipzig, Germany.
⁴ Centre for Infectious Diseases, Institute of Virology, Faculty of Veterinary Medicine, University of Leipzig, An den Tierkliniken 29, 04103, Leipzig, Germany. thomas.vahlenkamp@uni-leipzig.de.

^# Contributed equally.

Abstract

Background: Feedgrain contamination with mycotoxins, including deoxynivalenol (DON, "vomitoxin") is relatively frequently encountered. Pigs are particularly sensitive to the toxicity of DON. To assess the interplay between DON and porcine reproductive and respiratory syndrome virus (PRRSV), we performed an experimental DON exposure-PRRSV vaccination-challenge infection trial. Three-week-old piglets were divided into four groups. Groups I, II and III (10 animals/group) were vaccinated with a PRRSV modified live vaccine and 2 weeks later challenged with a heterologous field strain. While group I was not supplemented with DON, animals in groups II and III received DON for 4 weeks prior to challenge infection at levels that can be encountered in pig feed, employing a low-dose or high-dose regime (group II: 40 µg DON/kg body weight per day; group III: 80 µg DON/kg body weight per day, corresponding to approx. 1 or 2 mg DON/kg feed, respectively). Eight animals (group IV; unvaccinated, not DON exposed) served as control animals for the challenge infection.

Results: We assessed clinical signs, virus load in serum and various organs as well as antibody titres in the animals. All vaccinated animals mounted an efficient PRRSV-specific antibody response within 2 weeks, except for 20% of the animals receiving the higher DON dose. Upon virus challenge, the vaccinated animals in group I were protected from clinical signs. Vaccinated DON-exposed animals in group II and III were protected from clinical signs to a lesser extent. Clinical signs in group III receiving the higher dose of DON were as severe as in the (unvaccinated, not DON exposed) control group IV. The animals of group III also displayed lower antibody titres compared with the animals in group I and II.

Conclusions: The experimental vaccination/challenge study therefore revealed that exposure of pigs to DON for a period of 4 weeks deteriorates the efficacy of vaccination against clinical signs of PRRS.

Keywords: Arterivirus; Challenge; Deoxynivalenol; Modified live vaccine; Mycotoxin; Porcine reproductive and respiratory syndrome virus; Vaccination.