Chinese strain C, selecting strains with excellent cellular and humoral immune effects. Strict control, layer by layer checks, pure and free of exogenous viruses.1. Preferred strain: Chinese strain C, selecting strains with excellent cellular and humoral immune effects.2. Strict control: strict control, layer by layer inspection, pure and free of exogenous viruses.3. Unique technology: Using unique micro serum culture technology to reduce allergens.4. Efficient and stable: Ensure the quality control standard of the finished product, with an antigen content of ≥ 30000 RID per sample.Usage and dosage:Recommended immunization program (intramuscular injection): 1 dose for piglets, first immunization at 28-35 days of age, second immunization after one month; One reserve sow, immunized twice before mating (with an interval of one month); 1 sow per litter, every 4 months; P...