Key Swine Diseases Targeted by Vaccination
A structured vaccination program addresses the major infectious diseases that drive production losses in commercial and research swine herds.
Porcine Reproductive & Respiratory Syndrome (PRRS):
- One of the costliest swine diseases globally; causes reproductive failure in sows and respiratory disease in growing pigs
- MLV vaccines reduce clinical severity but do not eliminate the virus; herd-specific autogenous vaccines are increasingly used
- Vaccination strategy depends on herd PRRS status (negative, positive-stable, positive-unstable)
Erysipelas (Erysipelothrix rhusiopathiae):
- Causes three distinct syndromes: acute septicemia (sudden death), subacute diamond-skin urticaria, and chronic polyarthritis/endocarditis
- Highly vaccine-preventable; bacterins give reliable protection with a two-dose primary series and semi-annual boosters
- Unvaccinated gilts entering positive herds are at high risk
Porcine Circovirus Type 2 (PCV2) / Mycoplasma hyopneumoniae:
- PCV2 is associated with Porcine Multisystemic Wasting Syndrome (PMWS), PDNS, and reproductive failure
- Mycoplasma causes enzootic pneumonia (“chronic pneumonia” or “barking cough”) — a primary contributor to reduced FCR
- Combination vaccines at weaning provide excellent ROI in commercial herds
Swine Influenza (SIV):
- H1N1, H1N2, H3N2 subtypes circulate; herd-matched autogenous vaccines are increasingly important due to antigenic diversity
- Sow vaccination protects piglets via maternally derived antibodies in the first weeks of life
Ileitis (Lawsonia intracellularis):
- Causes porcine proliferative enteropathy; reduces weight gain in nursery/finisher pigs
- Oral live attenuated vaccine is highly effective but requires a 3-day antibiotic-free window before and after administration
E. coli / Clostridium (neonatal protection):
- Pre-farrow vaccination of sows/gilts is the primary tool for preventing neonatal scours (enterotoxigenic E. coli) and enterotoxemia (Clostridium perfringens type C)
- Colostral IgA transferred to piglets provides mucosal immunity in the small intestine
Designing a Herd Vaccination Program
Effective vaccination programs are tailored to herd health status, production flow, and regional disease pressure.
Core principles:
1. Veterinary oversight is mandatory: USDA-licensed vaccines require a valid veterinarian-client-patient relationship (VCPR). Extra-label use is governed by AMDUCA regulations.
2. Timing relative to key events: Vaccines work best when given far enough in advance to allow seroconversion before disease challenge. Pre-farrow timing protects both sow and piglets via colostrum.
3. Cold chain compliance: Most swine vaccines must be refrigerated at 35–46°F (2–8°C). Never freeze adjuvanted bacterins. Check expiration dates before each use.
4. Route and site: Follow product labels for intramuscular (IM), subcutaneous (SQ), or intranasal routes. For IM vaccines, use the neck (behind the ear) as the preferred injection site to avoid carcass trim losses.
5. Needle length and gauge: Use 1-inch, 18-gauge needles for IM administration in adult swine; ½–¾ inch needles for piglets under 15 kg.
6. Record-keeping: Document vaccine brand, lot number, expiration date, dose, route, and individual or group ID for each administration event.
7. Autogenous vaccines: When commercial products don’t adequately match circulating strains (e.g., SIV, PRRS), autogenous vaccines prepared from herd-specific isolates may be superior.
8. Biosecurity integration: Vaccination does not replace biosecurity. Incoming animals should be quarantined for at least 21–30 days and vaccinated to herd health status before commingling.