Pseudorabies Vaccine.

CFR · 2024-01-01 · US · Title 9

Pseudorabies Vaccine shall be prepared from virus-bearing cell culture fluids. Only Master Seed which has been established as pure, safe, and immunogenic shall be used for preparing seeds for vaccine production. All serials of vaccine shall be prepared from the first through the fifth passage from the Master Seed. (a) The Master Seed shall meet the applicable general requirements prescribed in § 113.300 and the requirements in this section. (b) Each lot of Master Seed shall be tested for immunogenicity. The selected virus dose shall be established as follows: (1) Twenty-five pseudorabies susceptible pigs (20 vaccinates and 5 controls) of the youngest age for which the vaccine is recommended, shall be used as test animals. Blood samples shall be taken from each pig and the serums inactivated and individually tested for neutralizing antibody against pseudorabies virus. Pigs shall be considered susceptible if there is no neutralization at a 1:2 final serum dilution in a constant virus-varying serum neutralization test using 50 to 300 TCID (2) A geometric mean titer of the vaccine produced at the highest passage (3) Fourteen to 28 days postvaccination, the vaccinates and controls shall be challenged with virulent pseudorabies virus furnished or approved by Animal and Plant Health Inspection Service and observed each day for 14 days. (i) If at least four of the five controls do not develop severe central nervous system signs or die, the test is a No Test and may be repeated. (ii)

official document · source cfr-2024 · id 9:§ 113.318