[Code of Federal Regulations]
[Title 9, Volume 1]
[Revised as of January 1, 2002]
From the U.S. Government Printing Office via GPO Access
[CITE: 9CFR113.102]

[Page 624]
 
                  TITLE 9--ANIMALS AND ANIMAL PRODUCTS
 
  CHAPTER I--ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF 
                               AGRICULTURE
 
PART 113--STANDARD REQUIREMENTS--Table of Contents
 
Sec. 113.102  Leptospira Icterohaemorrhagiae Bacterin.

    Leptospira Icterohaemorrhagiae Bacterin shall be produced from a 
culture of Leptospira icterohaemorrhagiae which has been inactivated and 
is nontoxic. Each serial of biological product containing Leptospira 
icterohaemorrhagiae fraction shall meet the applicable requirements in 
Sec. 113.100 and be tested for purity, safety, and potency as prescribed 
in this section. A serial found unsatisfactory by any prescribed test 
shall not be released.
    (a) Purity test. Final container samples of completed product from 
each serial and each subserial shall be tested for viable bacteria and 
fungi as provided in Sec. 113.26.
    (b) Safety test. Bulk or final container samples of completed 
product from each serial shall be tested for safety as provided in 
Sec. 113.38.
    (c) Potency test. Bulk or final container samples of completed 
product shall be diluted with physiological saline so that each 0.25 ml 
contains not more than 1/80th of the dose recommended on the label and 
shall be tested for potency, using the two-stage test provided in this 
paragraph.
    (1) Vaccinates. Inject each of at least 10 but not more than 12 
young adult hamsters, each weighing 50 to 90 grams, with 0.25 ml of the 
diluted bacterin either subcutaneously or intramuscularly, in accordance 
with the label recommendations for use.
    (2) Controls. Retain at least 10 but not more than 12 additional 
hamsters from the same group as unvaccinated controls.
    (3) Challenge. From 14 to 18 days postvaccination, challenge each of 
10 vaccinates and each of 10 controls intraperitoneally with a 
suspension of virulent Leptospira icterohaemorrhagiae organisms, using a 
dose of 10-10,000 hamster LD50 as determined by titration.
    (4) Post-challenge period. Observe the vaccinates and controls for 
14 days post-challenge and record all deaths. If eight or more controls 
die from leptospirosis, the test is valid and the results shall be 
evaluated according to the following table:

----------------------------------------------------------------------------------------------------------------
                                                                           Cumulative total    Cumulative total
                                       Number of       Cumulative number   dead hamsters for   dead hamsters for
              Stage                   vaccinates         of vaccinates       satisfactory       unsatisfactory
                                                                                serial              serial
----------------------------------------------------------------------------------------------------------------
1...............................  10................  10................  2 or less.........  5 or more.
2...............................  10................  20................  5 or less.........  6 or more.
----------------------------------------------------------------------------------------------------------------

    (5) If three or four vaccinates die in the first stage, the second 
stage shall be used. The second stage shall be conducted in a manner 
identical to the first stage.
    (6) If the second stage is used, each serial shall be evaluated 
according to the second part of the table. On the basis of cumulative 
results, each serial shall either pass or fail.

[39 FR 16862, May 10, 1974, as amended at 45 FR 40100, June 13, 1980. 
Redesignated at 55 FR 35562, Aug. 31, 1990, as amended at 56 FR 66785, 
Dec. 26, 1991]