[Code of Federal Regulations]
[Title 9, Volume 1]
[Revised as of January 1, 2006]
From the U.S. Government Printing Office via GPO Access
[CITE: 9CFR113.8]
[Page 623-627]
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. 113.8 In vitro tests for serial release.
(a) Master Seed which has been established as pure, safe, and
immunogenic shall be used for preparing seed for production as specified
in the Standard Requirements or in the filed Outline of Production. The
Administrator may exempt a product from a required animal potency test
for release when an evaluation can, with reasonable certainty, be made
by:
(1) Subjecting the master seed to the applicable requirements
prescribed in Sec. Sec. 113.64, 113.100, 113.200, and 113.300;
(2) Testing the Master Seed for immunogenicity in a manner
acceptable to the Animal and Plant Health Inspection Service (APHIS);
(3) Establishing satisfactory potency for the product in accordance
with the following provisions:
[[Page 624]]
(i) Potency for live products may be determined by log10
virus titer or determining the live bacterial count based on the
protective dose used in the Master Seed immunogenicity test plus an
adequate overage for adverse conditions and test error; and
(ii) Potency for inactivated products may be determined using tests
for relative antigen content by comparing the antigen content of the
test serial to a reference preparation using a parallel line immunoassay
or equivalent method which measures linearity, specificity, and
reproducibility in a manner acceptable to APHIS.
(b) In the case of live products, each serial and subserial of
desiccated product derived from an approved Master Seed and bulk or
final container samples of each serial of completed liquid product
derived from an approved Master Seed shall be evaluated by a test
procedure acceptable to APHIS. On the basis of the results of the test,
as compared with the required minimum potency, each serial and subserial
shall either be released to the firm for marketing or withheld from the
market. The evaluation of such products shall be made in accordance with
the following criteria:
(1) If the initial test shows the count or titer to equal or exceed
the required minimum, the serial or subserial is satisfactory without
additional testing.
(2) If the initial test shows the count or titer to be lower than
the required minimum, the serial or subserial may be retested, using
double the number of samples. The average counts or titers obtained in
the retests shall be determined. If the average is less than the
required minimum, the serial or subserial is unsatisfactory without
further consideration.
(3) If the average is equal to or greater than the required minimum,
the following shall apply to live virus vaccines:
(i) If the difference between the average titer obtained in the
retests and the titer obtained in the initial test is 10\0.7\ or
greater, the initial titer may be considered a result of test system
error and the serial or subserial considered satisfactory for virus
titer.
(ii) If the difference between the average titer obtained in the
retests and the titer obtained in the initial test is less than 10\0.7\,
a new average shall be determined using the titers obtained in all
tests. If the new average is below the required minimum, the serial or
subserial is unsatisfactory.
(4) If the average is equal to or greater than the required minimum,
the following shall apply to bacterial vaccines:
(i) If the average count obtained in the retests is at least three
times the count obtained in the initial test, the initial count may be
considered a result of test system error and the serial or subserial
considered satisfactory for bacterial count.
(ii) If the average count obtained in the retests is less than three
times the count obtained in the initial test, a new average shall be
determined using the counts obtained in all tests. If the new average
count is below the required minimum, the serial or subserial is
unsatisfactory.
(5) Exceptions. When a product is evaluated in terms other than
log10 virus titer or organism count, an appropriate
difference between the average potency value obtained in the retests and
the potency value obtained in the initial test shall be established for
use in paragraphs (b)(3) and (b)(4) of this section to evaluate such
products and shall be specified in the product Standard Requirement or
filed Outline of Production.
(c) In the case of inactivated products, bulk or final container
samples of completed product from each serial derived from an approved
Master Seed, shall be evaluated for relative antigen content (potency)
as compared with an unexpired reference by a parallel line immunoassay
or other procedure acceptable to APHIS.\1\ Firms currently using
immunoassays which do not satisfy this requirement shall have 2 years
from the effective date of the final rule
[[Page 625]]
to update their filed Outlines of Production to be in compliance with
this requirement unless granted an extension by the Administrator based
on a showing by the firm seeking the extension that they have made a
good faith effort with due diligence to achieve compliance. On the basis
of the results of such test procedures, each serial that meets the
required minimum potency shall be released to the firm for marketing;
each serial not meeting the required minimum potency shall be withheld
from the market. The evaluation of such products shall be made in
accordance with the following criteria:
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\1\ A method for evaluating relative antigen content, Supplemental
Assay Method 318, and relative potency calculation software are
available from the United States Department of Agriculture, Animal and
Plant Health Inspection Service, Veterinary Services, National
Veterinary Services Laboratories, Center for Veterinary Biologics--
Laboratory, 1800 Dayton Road, P. O. Box 844, Ames, Iowa 50010.
---------------------------------------------------------------------------
(1) A test that results in no valid lines is considered a ``no
test'' and may be repeated.
(2) An initial test (test 1) that results in valid lines that are
not parallel is considered a valid equivocal test. Release of the serial
may not be based on such test since the result cannot be termed
``satisfactory'' or ``unsatisfactory.''
(3) If the initial test (test 1) shows that potency equals or
exceeds the required minimum potency, the serial is satisfactory without
additional testing.
(4) If the initial test (test 1) is an equivocal test due to lack of
parallelism, the serial may be retested up to three times (tests 2, 3,
and 4) with disposition to be as specified in paragraphs (c)(4)(i) and
(ii) of this section; Provided, That, if the serial is not retested or
the other provisions of this section are not satisfied, the serial shall
be deemed unsatisfactory.
(i) If: The first retest (test 2) following an initial equivocal
test; the second retest (test 3) following two consecutive equivocal
tests (tests 1 and 2); or the third retest (test 4) following three
consecutive equivocal tests (tests 1, 2, and 3) shows that the potency
equals or exceeds the required minimum potency, the serial is
satisfactory.
(ii) If the first retest (test 2) following an initial equivocal
test shows that potency is less than the required minimum potency,
disposition of the serial will be based on the outcome of retests 2 and
3 (tests 3 and 4) as follows: if either retest (test 3 or 4) shows that
potency is less than the required minimum potency, the serial is
unsatisfactory. If either retest 2 or retest 3 (tests 3 or 4) is an
equivocal test, or in the event that each retest (tests 2, 3, and 4)
following an initial equivocal test is also an equivocal test, the
accumulated test results shall be considered indicative of a lack of
potency and release of the serial withheld. In which case, the licensee
may submit data confirming the continued validity of the test system to
APHIS for review and approval. If the data are acceptable to APHIS, the
potency test may be repeated by the firm, subject to the provisions
specified in paragraphs (i) and (ii) and confirmatory testing by APHIS.
(5) If the initial test (test 1) shows that potency is less than the
required minimum potency, the serial may be retested a minimum of two
times (tests 2 and 3) but not more than three times (tests 2, 3, and 4)
with disposition as specified in paragraphs (c)(5) (i) and (ii) of this
section; Provided, That, if the serial is not retested or the other
provisions of this section are not satisfied, the serial shall be deemed
unsatisfactory.
(i) If two consecutive retests (tests 2 and 3) show that potency of
the serial equals or exceeds the required minimum potency, the serial is
satisfactory. If one of the two retests (test 2 or 3) shows that the
potency is less than the required minimum potency, the serial is
unsatisfactory.
(ii) If one of the retests (tests 2 or 3) shows that the potency
equals or exceeds the required minimum potency and the other retest
(test 2 or 3) is an equivocal test, a third retest (test 4) may be
performed. If the third retest (test 4) shows that the potency of the
serial equals or exceeds the required minimum potency, the serial is
deemed satisfactory. If both retests (tests 2 and 3) or if the third
retest (test 4) is an equivocal test, the accumulated test results shall
be considered indicative of a lack of potency and release of the serial
withheld, in which case the licensee may submit data confirming the
continued validity of the test system to APHIS for review and approval.
If the data are acceptable to APHIS, the potency test may be repeated by
the firm, subject to the provisions specified
[[Page 626]]
in paragraphs (c)(4) (i) and (ii) and (c)(5) (i) and (ii) of this
section, and confirmatory testing by APHIS.
(d) Repeat immunogenicity tests. (1) The accuracy of the protective
dose established for live products in the Master Seed immunogenicity
test and defined as live virus titer or live bacterial count shall be
confirmed in 3 years in a manner acceptable to APHIS, unless use of the
lot of Master Seed previously tested is discontinued.
(2) All determinations of relative antigen content using parallel
line immunoassays or equivalent methods shall be conducted with an
unexpired reference. The lot of reference used to determine antigenic
content shall have an initial dating period equal to the dating of the
product or as supported by data acceptable to APHIS, except that frozen
references may have an initial dating of up to 5 years, Provided, That
the request for dating of the frozen references beyond the dating of the
product is supported by preliminary data acceptable to APHIS and
includes provisions for monitoring the stability of the reference to
determine when the potency starts to decline and for taking the
appropriate steps to requalify a reference with declining potency either
by testing a Qualifying Serial in host animals or by providing other
evidence of immunogenicity, e.g., antibody titers or laboratory animal
test data previously correlated to host animal protection in a manner
acceptable to APHIS. Prior to the expiration date, such reference may be
granted an extension of dating, Provided, That its immunogenicity has
been confirmed using a Qualifying Serial of product in a manner
acceptable to APHIS. The dating period of the Master Reference and
Working Reference may be extended by data acceptable to APHIS if the
minimum potency of the Master Reference is determined to be adequately
above the minimum level needed to provide protection in the host animal.
If a new Master Reference is established, it shall be allowed an initial
dating period equal to the dating of the product or as supported by data
acceptable to APHIS, except that frozen references may have an initial
dating period of 5 years, or as supported by data acceptable to APHIS.
Prior to the expiration date, such reference may be granted an extension
of dating by confirming its immunogenicity using a Qualifying Serial of
product.
(e) Final container samples of completed product derived from Master
Seed found immunogenic in accordance with paragraph (a) of this section
and found satisfactory in accordance with paragraphs (b) and (c) of this
section may also be subjected to an animal potency test by Animal and
Plant Health Inspection Service as provided in this paragraph. Products
shall be used according to label directions including dose(s) and route
of administration.
(1) A one stage test using 20 vaccinates and 5 controls or a two
stage test using 10 vaccinates and 5 controls for each stage shall be
used. The criteria used for judging the specific response in the
controls and vaccinates shall be in accordance with the test protocol
used in the Master Seed immunogenicity test.
(2) If at least 80 percent of the controls do not show specific
responses to challenge, the test is inconclusive and may be repeated. If
a vaccinate shows the specific responses to challenge expected in the
controls, the vaccinate shall be listed as a failure.
(3) The results of the testing shall be evaluated according to the
following table:
Cumulative totals
------------------------------------------------------------------------
Number Failures for Failures for
Stage of satisfactory unsatisfactory
animals serials serials
------------------------------------------------------------------------
1............................. 10 1 or less..... 3 or more.
2 (or 1)...................... 20 4 or less..... 5 or more.
------------------------------------------------------------------------
(4) When a serial has been found unsatisfactory for potency by the
test provided in paragraphs (e)(1), (2), and (3) of this section, the
serial shall be withheld from the market and the following actions
taken:
(i) The Administrator shall require that at least two additional
serials prepared with the same Master Seed be subjected to similar
animal potency tests by Animal and Plant Health Inspection Service or
the licensee or both.
(ii) If another serial is found unsatisfactory for potency, the
product shall be removed from the market while a
[[Page 627]]
reevaluation of the product is made and the problem is resolved.
[49 FR 22625, May 31, 1984, as amended at 56 FR 66784, 66786, Dec. 26,
1991; 62 FR 19038, Apr. 18, 1997]