Bovine Parainfluenza

CFR · 2024-01-01 · US · Title 9

Bovine Parainfluenza (a) The Master Seed Virus shall meet the applicable general requirements prescribed in § 113.300. (b) Each lot of Master Seed Virus shall meet the special requirements prescribed in this section. (c) Each lot of Master Seed Virus used for vaccine production shall be tested for immunogenicity. The selected virus dose from the lot of Master Seed Virus shall be established as follows: (1) Twenty-five bovine parainfluenza, susceptible calves shall be used as test animals (20 vaccinates and five controls). Blood samples shall be drawn from these animals and individual serums tested. Also, nasal specimens (i) The results are negative at a 1:2 final serum dilution in a varying serum constant virus neutralization test with less than 500 TCID (ii) Shall be negative to bovine parainfluenza (2) A geometric mean titer of the dried vaccine produced from the highest passage of the Master Seed Virus shall be established before the immunogenicity test is conducted. The 20 calves to be used as vaccinates shall be injected with a predetermined quantity of vaccine virus and the remaining five calves held as uninjected controls. To confirm the dosage calculation, five replicate virus titrations shall be conducted on a sample of the vaccine virus dilution used. (3) The vaccinates and controls shall be examined for clinical signs of respiratory disease and the body temperature taken and recorded on each of the first 14 consecutive days post-injection. The vaccinates shall be b

official document · source cfr-2024 · id 9:§ 113.309