Reducing risks of antimicrobial resistance in livestock production: Vaccines keep pig herds healthy

Antimicrobial resistance is becoming one of the greatest challenges of the 21st century. In Vietnam, high levels of antibiotic use, especially in pig farming, are accelerating the spread of drug-resistant bacteria. This reality highlights the close link between human, animal, and environmental health under the One Health approach.

Antimicrobial resistance is classified by severity into MDR (multidrug-resistant), XDR (extensively drug-resistant), and PDR (pan-drug-resistant). According to Dr. Vo Thi Tra An from the Faculty of Animal Science and Veterinary Medicine (Nong Lam University - Ho Chi Minh City), the main cause is improper antibiotic use, which allows bacteria to develop resistance mechanisms such as producing degrading enzymes, increasing drug efflux pumps, or altering binding targets.

In animal husbandry, antibiotics are used for three purposes: treatment, disease prevention, and growth promotion. Overuse increases the risk of transmitting multidrug-resistant bacteria to people through food and the environment, particularly in the case of antibiotics critical for human medicine, such as fluoroquinolones and colistin.

Antibiotic consumption in Vietnam’s livestock sector in 2015 was estimated at 2,751 tons, with pigs accounting for 1,600 tons, higher than usage in human healthcare (1,086 tons). The consequences include reduced treatment effectiveness, higher mortality rates, lower productivity, and increased production costs. For example, post-weaning diarrhea can cause mortality rates of 10 - 20%, while medication costs may double or triple.

In response, Vietnam has implemented a roadmap to reduce antibiotic use. From January 1, 2020, antibiotics for growth promotion in animal feed were banned. By December 31, 2021, the use of critically important antibiotics in feed was prohibited. The next goal is a complete ban on antibiotic use for preventive purposes from January 1, 2026, under Decree 13/2020/ND-CP and Circular 12/2020/TT-BNNPTNT.

As reliance on antibiotics declines, vaccines are proving to be a sustainable solution. Proactive disease prevention through vaccination, combined with improved housing conditions, biosecurity, and proper nutrition, helps pig herds maintain health and productivity.

According to Nguyen Cong Huy, Technical Director of Boehringer Ingelheim Vietnam, experience from the Netherlands shows that over 14 years, antibiotic use fell by 70% while pig productivity increased significantly. International studies also demonstrate that PCV2 vaccines can reduce antibiotic use for respiratory diseases by more than 50%.

“Enterisol® Ileitis vaccination reduces antibiotic use by up to 79% in the prevention and treatment of ileitis, and can even replace some commonly used antibiotics. Another trial showed vaccinated pig herds required 36% fewer antibiotics and saved an average of €5.5 per pig thanks to lower drug costs, improved feed efficiency, and better growth,” Huy said.

The post-weaning stage is the most sensitive period as maternal antibodies decline and pigs experience high stress, accounting for approximately 80% of antibiotic use. “Most major pig diseases now have effective vaccines, enabling pigs to develop active immunity early, overcome immune stress, and reduce the need for antibiotics,” said the Technical Director of Boehringer Ingelheim Vietnam.

He also noted that gut health is the foundation of productivity, and live oral vaccines can induce dual immunity - mucosal and cell-mediated - without stressing the animals.

Apart from vaccination, integrated solutions are also essential. Farmers should follow the “five rights” in antibiotic use: right disease, right drug, right dose, right route, and right duration. Applying alternatives such as probiotics, organic acids, and herbal products, together with strong biosecurity measures, can enhance immunity and reduce disease outbreaks. Cross-sector collaboration among human health, veterinary, and environmental agencies under the One Health approach is crucial for monitoring resistance, tracing sources, and preventing spread.

Niklas Birkner, General Director of Boehringer Ingelheim Vietnam, said, “When animals are healthy, people become healthier. Vaccines and proactive disease prevention are key to maintaining productivity, ensuring food safety, and curbing antimicrobial resistance.”

Vietnam’s pig industry is currently undergoing a major transformation. Reducing reliance on antibiotics presents significant challenges for farmers, but also opens opportunities to improve product quality and meet export standards.

Many modern farms have adopted integrated biosecurity, nutrition management, and proactive disease prevention measures alongside vaccination, significantly reducing disease risks and treatment costs. Together with stricter antibiotic regulations, these efforts are gradually shaping a sustainable and safe pig farming sector that meets domestic demand while moving toward export markets.