Vaccination programs protect livestock from preventable diseases, reducing welfare harm at the population level while requiring individual animal handling that is itself a welfare consideration.
Livestock vaccination programs represent a clear welfare-positive intervention at the population level. Preventing serious diseases like bovine viral diarrhea, which causes reproductive failure, immune suppression, and death, avoids far more welfare harm than the transient handling stress of vaccination. Effective herd immunity through vaccination also protects vulnerable animals including immunocompromised or pregnant animals. The welfare case for comprehensive vaccination programs is robust. The implementation challenge is ensuring handling during vaccination is conducted with low-stress techniques that minimize the welfare cost of the procedure.