Immunization Process for Gestating Sows

Immunization work in pig farms is essential to prevent various swine diseases. The immunization of gestating sows is a key focus of farm  epidemic prevention, but the immunization priorities vary across farms under different conditions, requiring adjustments based on actual circumstances. So, how should sows be immunized correctly? What is the immunization process for gestating sows?

Common Misconceptions and Risks in Immunization

For example, some enterprises exaggerate the effects of certain immunological adjuvants or so-called immune enhancers in product promotion. Their manuals may list an immunization schedule recommending up to 11 immunizations during gestation, even including live Porcine Parvovirus Vaccine—which should be administered before mating, as post-mating vaccination is ineffective. Marketing staff may emphasize the "necessity" of each immunization to farm owners, simultaneously promoting their products as vital for ensuring immunogenicity. In reality, most small-to-medium farms only immunize gestating sows 4 to 5 times. New or previously diseased farms, or those with new technical directors, may over-immunize out of caution, increasing immune stress and disease risk.

Gestating sows—whether primiparous or multiparous—are in a state of physiological stress, and immunization adds the burden of additional stress. It is unscientific to claim no side effects on fetuses or the dam. A concise, prioritized immunization plan aligns better with the physiological needs of gestation.

Key Principles for Immunization During Gestation

1. Prioritize Essential Vaccines: Ensure no critical vaccinations are missed, and administer them at the correct time. Avoid blindly trusting"expert" or manual recommendations to add unnecessary immunizations.
2. Case-by-Case Adjustment: Tailor the schedule to the farm’s disease history, local epidemiology, and antibody detection results (e.g., for Porcine Epidemic Diarrhea).

Specific Vaccines and Rational Administration

1. Japanese Encephalitis (JE) Vaccine

• Rational Practice: Universal immunization is conducted in March–April (before mosquito activity) and September (during mosquito season). Primiparous sows receive 1 dose before mating, with a booster 2–3 weeks later. Multiparous sows typically only need universal immunization.
• Caution: Avoid vaccinating pregnant sows, as cases of abortion and malformed fetuses after JE vaccination during gestation have been reported.

2. Classical Swine Fever (CSF) Vaccine

• Outdated Practice: Vaccinating gestating sows is obsolete. Live CSF virus can cross the placenta, causing fetal virus carriage, neonatal CSF, or environmental virus shedding.
• Correct Timing: Administer live vaccines to multiparous sows after piglets wean, alongside annual universal immunization.

3. E. coli Vaccine for Neonatal Diarrhea

• Limitations: Due to the diversity and rapid mutation of pathogenic E. coli strains, live vaccines only reduce morbidity rather than completely preventing yellow/white scours.
• Comprehensive Measures: Prioritize environmental hygiene, disinfection, diet control, and temperature/humidity management.

4. Streptococcus Suis Vaccine

• Serotype Dependence: Vaccines must match the local serotype, as cross-protection between serotypes is low. For farms with a history of infection, vaccinate sows 1 month before farrowing.
• Alternative Prevention: Focus on sanitation, disinfection, and wound care.

5. Atrophic Rhinitis Vaccine

• Low Prevalence: Routine vaccination is unnecessary in most farms, as the disease is no longer a major threat.

6. Clostridium perfringens Type C (Red Diarrhea) Vaccine

• Selective Use: Primiparous sows may be vaccinated 30 and 15 days before farrowing, but many farms prevent red diarrhea through refined management without vaccination, especially in disease-free settings.

Vaccines Mandatory During Gestation

1. Foot-and-Mouth Disease (FMD) Vaccine
2. Porcine Reproductive and Respiratory Syndrome (PRRS) Vaccine
3. Pseudorabies (PRV) Vaccine: Administering in early gestation prevents abortion, stillbirths, and mummified fetuses. Lactating piglets acquire passive immunity via colostrum, which lasts 3–4 weeks.

Critical Considerations for Immunization Quality

• Operational Errors: Avoid mistakes like improper vaccine storage, reusing needles, inadequate disinfection, or using incorrect diluents (e.g., saline instead of specific diluents).
• Management Correlation: Poor husbandry (e.g., poor ventilation, high density, dirty water, inadequate waste disposal) disrupts hormone balance, reduces immunity, and undermines vaccination efficacy.
• Core Principle: Immunization efficacy relies on comprehensive management. Gestating sow immunization should prioritize "quality over quantity," with fewer, targeted vaccinations outweighing excessive schedules.
• In practice, farm technicians must avoid rote vaccination and instead base decisions on evidence, local epidemiology, and antibody monitoring. By balancing scientific rigor with practical management, we can optimize disease prevention for gestating sows and piglets, moving toward healthier swine production.