[Federal Register Volume 62, Number 75 (Friday, April 18, 1997)]
[Rules and Regulations]
[Pages 19033-19039]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-10100]
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DEPARTMENT OF AGRICULTURE
Animal and Plant Health Inspection Service
9 CFR Parts 101 and 113
[Docket No. 94-051-3]
RIN 0579-AA66
Viruses, Serums, Toxins, and Analogous Products; In Vitro Tests
for Serial Release
AGENCY: Animal and Plant Health Inspection Service, USDA.
ACTION: Final rule.
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SUMMARY: We are amending the regulations to provide for the use of in
vitro potency tests when conducting immunoassays to determine the
relative antigen content (potency) of a serial of inactivated
veterinary biological product once immunogenicity is established using
host animal tests. Such tests would be conducted using unexpired
immunogenic reference preparations and parallel line assays, or other
methods which demonstrate linearity, specificity, and reproducibility
at least equivalent to the parallel line assay. Firms currently using
immunoassays which do not meet the standard in this amendment will have
2 years from the effective date of this final rule to update their
filed Outlines of Production. This amendment also changes the title of
the section and adds definitions of ``Master reference,'' ``Working
reference,'' ``Qualifying serial,'' and ``Immunogenicity'' to the
regulations.
The effect of this action is to standardize requirements for in
vitro immunoassay potency tests for inactivated products which cannot
be evaluated on the basis of virus titer or bacterial counts.
EFFECTIVE DATE: May 19, 1997.
FOR FURTHER INFORMATION CONTACT: Dr. David A. Espeseth, Director,
Center for Veterinary Biologics, Licensing and Policy Development, VS,
APHIS, 4700 River Road, Unit 148, Riverdale, MD 20737-1237, (301) 734-
8245.
SUPPLEMENTARY INFORMATION:
Background
The regulations pertaining to the testing of biologics provide that
no biological product shall be released (for sale) prior to the
completion of tests prescribed to establish the product to be pure,
safe, potent, and efficacious (9 CFR 113.5). Efficacy refers to the
specific ability of the product to effect the result for which it is
offered when used as recommended by the manufacturer. Tests to
establish efficacy include immunogenicity tests in host animals using
product which is manufactured according to specified requirements which
include specifications for antigen content and/or animal potency. If a
product has been tested for immunogenicity in animals and shown to
elicit the desired immune response, it should follow that subsequent
serials (batches) of the product manufactured to the same
specifications should also have the same effect. Based on this premise,
once immunogenicity is established in relation to a specific minimum
antigen content, it should no longer be necessary to test every
subsequent product serial for potency in animals if an evaluation of
the relative antigen content can be made by testing the serial or
subserial in an acceptable in vitro test system. Therefore, when
properly qualified and validated, in vitro immunoassays that determine
relative antigen content of a product can serve as acceptable
substitutes for potency tests that otherwise would need to be performed
in animals.
The regulations in 9 CFR 113.8 pertain to the use of in vitro tests
for determining the potency of serials and/or subserials of veterinary
biological products after required animal tests are completed. Prior to
this amendment, the in vitro test procedures prescribed in Sec. 113.8
were only applicable to products containing live microorganisms. With
these amendments Sec. 113.8 will be applicable to both live and
inactivated products.
On May 17, 1995, we published in the Federal Register (60 FR 26381-
26384, Docket No. 94-051-1) a proposal to amend the regulations
regarding the use of in vitro potency tests in place of animal tests
for immunogenicity. The proposed rule provided for the use of a
parallel line assay, or other valid method, and an unexpired reference
preparation in an in vitro immunoassay for relative antigen content to
determine the potency of a serial of inactivated product. In proposing
the parallel line assay or equivalent valid method and the use of an
unexpired reference as a standard for in vitro immunoassay potency
tests for serial release, APHIS did not intend to preclude the
validation of existing in vitro immunoassays or the adoption of
technological advances in antigen quantitation.
We solicited comments concerning our proposal for 90 days ending
August 15, 1995. We extended the comment period an additional 30 days
ending September 14, 1995 (60 FR 36743-36744, Docket No. 94-051-2, July
18,
[[Page 19034]]
1995). We also announced that we would be having a public hearing on
August 1, 1995, in Ames, IA, to have further discussion related to in
vitro testing by interested persons. We received comments from four
licensed manufacturers, and a national trade association representing
U.S. manufacturers of animal health products. Three comments from
biologics producers were received at the public hearing on August 1,
1995, in Ames, IA. While generally supportive of in vitro immunoassay
tests for determining the relative antigen content and thereby the
potency of products, most commenters suggested changes in one or more
sections as proposed. Others suggested that the comment period be
extended and the proposal be submitted to negotiated rulemaking. We
carefully considered all of the comments we received. They are
discussed below.
Analysis of Comments and APHIS' Response
Four commenters requested that the comment period be further
extended for 10 months beyond September 14, 1995, and that negotiated
rulemaking be initiated. In response to this comment, APHIS notes that
the history of this rulemaking began with a proposed rule published on
May 17, 1995 (60 FR 26381-26384, Docket No. 94-051-1). The comment
period of 90 days was extended to 120 days until September 14, 1995, in
response to a request for an extension from a national trade
association (See 60 FR 36743, July 18, 1995, Docket No. 94-051-2). In
addition, a public hearing was held on In Vitro Potency Testing on
August 1, 1995, in Ames, IA to obtain further comment on this topic.
Contrary to the commenters' request, the comment period cannot be
further extended for negotiated rulemaking because the initiation of
negotiated rulemaking necessitates the withdrawal of the current
proposal and the proposal of another rule after the conclusion of the
negotiated rulemaking. APHIS believes that the publication of a final
rule with appropriate consideration of responses and comments would be
a more efficient way of handling this matter and would allay concerns
and clarify issues raised by the commenters. Therefore, the request for
further extension of the comment period and initiation of negotiated
rulemaking is not granted.
Two commenters expressed concern that by specifying that in vitro
immunoassays used to determine relative antigen content be parallel
line assays, APHIS would be imposing a requirement which would not
allow the industry to take advantage of technological advances that are
occurring in the area of antigen quantitation. APHIS proposed the
parallel line assay as a standard for immunoassay tests for relative
antigen content. Assay formats which are equivalent to or exceed the
parallel line assay standard could have been used as provided for in 9
CFR 113.4. In response to these comments, however, APHIS has amended
Secs. 101.5(q) and 113.8(a) in the final rule to provide specifically
for the use of other valid methods for determining relative antigen
content which demonstrate linearity, specificity, and reproducibility
at least equivalent to the parallel line assay.
Five commenters recommended amending the rule to allow laboratory
animal tests and antibody titers that have been correlated to host
animal protection to be used to requalify or extend the dating of
reference preparations. One of the commenters pointed out that the
proposed standard requirement for Escherichia coli (E. coli) bacterins
(59 FR 51390-51392, October 11, 1994) which also uses a parallel line
immunoassay to test for potency, includes such a provision. In
addition, the commenter interpreted the E. coli standard requirement to
imply that in vitro assays may be used in place of reference
requalification in host animals. In response to the commenter, APHIS
agrees that the proposed E. coli standard requirement allows antibody
titers and laboratory animal studies, previously correlated to
protection, to be used to requalify reference preparations. These same
provisions were available under the proposal to amend Secs. 101.5 and
113.8 (See proposed terminology in Sec. 101.5(o) which provides for
direct or indirect correlation of potency to host animal
immunogenicity). However, by specifying in proposed Sec. 101.5(q)(1)
that Qualifying Serials used to requalify or extend the dating of a
Master Reference shall be ``tested for immunogenicity in host
animals,'' APHIS may have inadvertently implied that laboratory animal
tests could not be used for reference requalification. This was not the
intent of the proposed regulation. In response to the commenter, the
final rule has been amended in Sec. 101.5(q)(1) to clarify the
definition of Qualifying Serial to provide for the use of procedures
acceptable to APHIS which will include antibody titers and laboratory
animal testing along with host animal immunogenicity for reference
requalification.
In response to the comment regarding the use of in vitro assays to
requalify or extend the dating of a reference in place of performing
studies in animals, in vitro tests may not be substituted for animal
tests for reference requalification. The proposed E. coli standard
requirement stated that an in vitro procedure may be used to monitor
the potency of the Master Reference for indication of decline, but
specified that the reference must be requalified when a decline in
potency is detected. As proposed in the proposed E. coli standard
requirement, the immunogenicity of Qualifying Serials used in reference
requalification studies may be based on host animal studies (challenge
or antibody titer) or laboratory animal studies as provided in
protocols acceptable to APHIS. Therefore, to clarify these points and
to eliminate the apparent inconsistency between the two proposed rules,
APHIS is amending Sec. 113.8(d)(2) pertaining to in vitro testing to
include a monitoring provision and to clarify that: (1) The monitoring
procedure can only be used to monitor the unexpired reference to detect
when a decline in potency has occurred between requalification
intervals, and (2) to specify that, if such monitoring procedures
indicate the potency of the reference is declining, the reference must
be requalified either by testing a Qualifying Serial in host animals or
by providing other evidence of reference immunogenicity, e.g., antibody
titers or laboratory animal test data previously correlated to host
animal protection, or a new reference must be prepared and qualified.
In vitro monitoring, however, would not be a substitute for reference
requalification at the end of product dating.
One commenter suggested amending Sec. 113.8(c)(5) to include a
provision to allow a firm to declare a potency test with valid lines a
``no test'' if the firm does not have confidence in the test result.
APHIS does not agree that it would be appropriate to declare such a
test a ``no test''. The regulation, as proposed, allows a firm to
retest a serial two times when the initial test shows that potency is
less than the required minimum potency. The commenter's suggestion,
however, would make potency testing subjective and allow a firm to
disregard valid results that are not consistent with a desired outcome.
Conceivably, a serial with unsatisfactory test results could be
retested indefinitely. In response to this comment, APHIS has clarified
provisions for the retesting of such serials and permitted up to three
retests to be performed. Provisions have also been added to permit the
potency test to be repeated under certain specified conditions.
Two commenters requested that firms be allowed more than two years
to
[[Page 19035]]
convert currently approved in vitro immunoassays that are described in
filed Outlines of Production that are not parallel line assays, to
parallel line assays or to another method which demonstrates linearity,
specificity, and reproducibility at least equivalent to the parallel
line assay. They believed that the two-year timetable will have a
negative impact on new product development, and therefore result in
fewer new products on the market. In response, APHIS realizes that some
firms may require more than two years to convert to parallel line
assays or other valid methods. However, two years from the effective
date of the final rule should be adequate time for most firms to
validate their immunoassays and requalify references for existing
products, considering that a single reference requalification procedure
may be applicable to several different products. Also, those firms
experiencing difficulty in meeting the time period may be granted
additional time, if justified, by requesting an extension as provided
in the regulations. Therefore, no change to the regulations is made in
response to these comments.
One commenter requested that the definition of ``Master Reference''
in Sec. 101.5(o) be amended to include options and directions for
stabilizing and storing reference preparations. The commenter believed
that this will result in more options for treating the references.
APHIS does not agree that the rule needs to be amended. The definition
of a ``Master Reference'' does not limit the options available to firms
when it comes to stabilizing, storing, lyophilizing, or freezing Master
References provided that such procedures are described in the filed
Outline of Production. Specifying such procedures in the definition,
however, would limit the industry to the procedures defined. Since the
proposed definition does not limit the available options, no change to
the regulations is made in response to this comment.
Another commenter requested clarification of proposed Sec. 101.5(p)
of the regulations. The commenter inquired if a purified antigen
preparation could serve as the Working Reference. As proposed in
Sec. 101.5(p) of the regulations, the Working Reference may be the
Master Reference, and since the Master Reference may be a purified
preparation of the protective immunogen (antigen), it follows that a
purified antigen can serve as the Working Reference. Therefore, no
change to the regulations is made in response to this comment.
One commenter recommended amending proposed Sec. 101.5(q)(1) of the
rule to require Qualifying Serials for reference requalification to be
produced at the minimum antigen level specified in the Outline of
Production instead of specifying that the geometric mean relative
potency not exceed 1.0 when compared to the Master Reference. The
commenter reasoned that, by specifying that the amount of antigen in
the Qualifying Serial not exceed the amount of antigen contained in the
Master Reference, the antigen level contained in the Master Reference
is a more appropriate benchmark (measure of protection) than is the
antigen content specified in the Outline of Production. The commenter
believed that the amount of antigen specified in the Outline of
Production should establish the antigen requirement for the Qualifying
Serial. APHIS does not agree with the commenter's recommendation. In
measuring relative potency, the antigen level used to demonstrate host
animal protection becomes the benchmark by which other serials are
measured and is the level of antigen to be contained in a Qualifying
Serial that is used to determine if the Master Reference is still
protective and therefore eligible for continued use in the potency
assay. The commenter's recommendation of using a regular production
serial and devising a calculation procedure to show antigen equivalency
is an indirect method that was considered by APHIS and determined to be
inappropriate and less meaningful than the provision in the APHIS
proposal. Therefore, no change to the regulations is made in response
to this comment.
Two commenters expressed confusion regarding proposed
Secs. 113.8(a)(4) (i) and (ii) of the rule. The commenters noted that
although Sec. 113.8(a)(4) refers to in vitro methods for determining
the potency of inactivated products, the cited examples, i.e.,
determining log10 virus titer and determining the live bacterial
count only apply to live products. APHIS agrees that the wording of
proposed Sec. 113.8(a)(4) is contradictory and has amended the final
rule, eliminating the contradictory sections, by incorporating the
provisions of Sec. 113.8(a)(4) into Sec. 113.8(a)(3) as follows:
(3) Establishing a satisfactory potency test for the product in
accordance with the following provisions:
(i) Potency of 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.
One commenter requested that the phrase ``an appropriate
difference'' referred to in proposed Sec. 113.8(b)(5) be further
defined. Proposed Sec. 113.8(b)(5) pertains to in vitro potency tests
for live vaccines in which potency is measured in terms other than
log10 virus titer or live bacterial counts, e.g., Marek's Disease
vaccines in which potency is measured in terms of plaque forming units
(PFU). Generally, an appropriate difference pertains to how a serial is
determined to have satisfactory potency when the initial potency test
determines that the serial contains less than the number of PFU's
specified in the Outline of Production (OP) or standard requirement and
the manufacturer elects to retest the serial to rule out test system
error as the cause of the unsatisfactory test result. In accordance
with Sec. 113.8(b)(5), the manufacturer must specify in the OP the
difference between the average PFU count obtained in the retest and the
PFU count obtained in the initial test so that the initial test may be
considered a result of test system error. The commenter did not suggest
what this appropriate difference in PFU or organism count should be.
APHIS has noted that the appropriate difference between test results
may be different for each product and this is the reason the proposed
rule specified that this value should be placed in the product Standard
Requirement or filed OP. From data submitted to APHIS, however, it is
also noted that an acceptable guideline for determining such
appropriate difference would be if the difference between the average
PFU count obtained in the retest and the count obtained in the initial
test exceeds 20 per cent. However, because no specific value was
proposed by the commenter, and there is a need to address specific
product differences, no change to the regulation is made in response to
this comment.
One commenter proposed that tests for relative antigen content
which cannot be termed satisfactory or unsatisfactory should be called
``no tests'' and be eligible for unlimited retesting without prejudice.
In response, APHIS points out that Sec. 113.8(c)(1) of the regulation
classifies a test that results in no valid lines as a ``no test''.
Typically, this designation is used when a deficiency in the test
system renders an invalid test result which is
[[Page 19036]]
unsuitable for reaching a conclusion regarding the potency of a serial;
such serials may be retested. An equivocal test as that test is used in
Sec. 113.8(c)(2), is a test that results in valid lines which are not
parallel. Therefore, the test is considered inconclusive and the serial
cannot be termed satisfactory or unsatisfactory. In order to clarify
the proper handling and disposition of serials of product with
equivocal test results, APHIS has amended Secs. 113.8 (c) (4) and (5)
regarding the retest of serials with equivocal test results due to a
lack of parallelism by specifying (1) the number of times such serials
may be retested and, (2) the disposition of the serial based on the
results of the retest.
Four comments were received related to proposed Sec. 113.8(d)(2).
The commenters requested that: (1) Stabilized Master References be
allowed to serve as Working References; (2) Master References be
allowed an initial dating period at least twice as long as that allowed
for a regular serial of product; and (3) Frozen references be allowed
an initial expiration dating of 5 years, provided that they are
monitored by in vitro methods. In response to these comments regarding
item (1), APHIS notes that proposed Sec. 101.5(o) of the regulation
specifies that the Master Reference may be used as the Working
Reference. Regarding item (2), proposed Sec. 113.8(d)(2) specifies that
the dating of the reference shall be equal to the dating of the product
or as supported by data acceptable to APHIS. Stability can be
demonstrated by repeat testing of the reference over time or by
demonstrating that the reference has maintained immunogenicity after
being stored for a period of time equal to or greater than the dating
period requested. Regarding item (3), allowing longer dating for
references based on special treatments or storage conditions may be
justified if such treatments or storage conditions are better able to
maintain the stability of the reference. Section 113.8(d)(2) provides
for determining the stability of the reference on the basis of
confirming the immunogenicity in a manner acceptable to APHIS. This
would include data from a stabilized monitored reference demonstrating
stability in a manner acceptable to APHIS. Therefore, a reference may
be allowed to have an initial dating longer than that for a regular
production serial, provided that the request for the longer initial
dating is supported by appropriate preliminary data and provides for
monitoring stability to determine when the potency of the reference
starts to decline and for taking appropriate steps to requalify or
replace such a reference.
In response to the commenters, APHIS has amended the regulations to
allow frozen references an initial dating period of 5 years, provided
that the request for such initial dating is supported by preliminary
data and a frozen storage protocol, including monitoring procedures,
acceptable to APHIS. As amended, Sec. 113.8(d)(2) reads as follows:
(d)(2) * * * 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 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. * * *
APHIS received two comments on proposed Sec. 101.5(q)(2) inquiring
into the rationale for requiring the qualifying serial used to extend
the dating of a Master Reference to be prepared within 6 months of
initiating a requalification test. The commenters believed that the 6
month restriction limited their options relating to production
schedules and antigen manufacture. APHIS proposed the 6 month
restriction as a means of assuring that qualifying serials used to
extend the dating of a reference would be representative of the firm's
current production method. APHIS agrees with the commenters regarding
the potential restrictive aspects of the 6 month requirement and has
amended Sec. 101.5(q)(2) in response to the comment to be more
consistent with our intent as follows:
(2) Qualifying serials used to requalify or extend the dating
period of a Master Reference shall be determined to be immunogenic
in accordance with methods deemed appropriate by APHIS as provided
in paragraph (a)(1) of this section, and, in addition, shall be
within their permitted dating period and have been prepared in
accordance with the production method described in the currently
filed Outline of Production.
APHIS received one comment requesting clarification of proposed
Sec. 113.8(d)(1) concerning confirmation of the protective dose
established for live products in the Master Seed immunogenicity test
after three years. In response to this comment, confirming the accuracy
of the protective dose for live products three years after completion
of a satisfactory immunogenicity test is specified in the Standard
Requirements for live viral vaccines, and in the filed Outline of
Production for products where standards have not been codified.
Including a reference to this requirement for live viral vaccines in
Sec. 113.8(d)(1) corrects an omission and provides notification of the
requirement to those unfamiliar with this provision of the regulations.
As specified in the codified requirements for individual live viral
vaccines, only one retest is required. No change to the regulations is
made in response to this comment.
We received two comments regarding the definition of a ``Qualifying
Serial'' in Sec. 101.5(q)(1). The commenter expressed concern that
limiting a qualifying serial to a relative potency, when compared to
the Master Reference, of not greater than 1.0 is too restrictive. The
commenters suggested that the normal tolerance limits of 15
per cent for parallel line immunoassays could cause a Qualifying Serial
set at 1.0 to be as low as 0.85, which means that it may not pass a
requalification test in animals. APHIS does not agree that requiring
the Qualifying Serial to have a mean relative potency of not greater
than 1.0 is too restrictive. As the commenter is probably aware, test
assay variation is to be expected. Usually, a manufacturer will
optimize the test system to determine how much variation is normal, and
adjust the antigen levels so that the risk of failing a requalification
test in animals is minimized. The alternative would require APHIS to
include tolerance limits in the regulations. APHIS does not agree that
such tolerance limits are necessary. The individual manufacturers can
optimize antigen levels based on their individual experiences with test
assay variation to assure that a Qualifying Serial with a mean relative
potency of not greater than 1.0 will pass the requalification test in
animals. No change to the regulations is made in response to this
comment.
Therefore based on the rationale set forth in the proposed rule and
in this document, we are adopting the provisions of the proposal as a
final rule, with the changes discussed in this document.
[[Page 19037]]
Executive Order 12866 and Regulatory Flexibility Act
This rule has been reviewed under Executive Order 12866. The rule
has been determined to be not significant for purposes of Executive
Order 12866, and therefore, has not been reviewed by the Office of
Management and Budget.
This amendment allows any valid in vitro immunoassay to be used in
determining the relative antigen content of an inactivated veterinary
biological product, provided that it satisfies the parallel line
criteria or demonstrates linearity, specificity, and reproducibility
equivalent to the parallel line assay using an unexpired reference
preparation. This amendment affects all licensed manufacturers of
veterinary biologicals utilizing in vitro relative potency immunoassays
for determining the potency of animal biological products. There are
currently approximately 118 veterinary biologics establishments that
may be affected by this rule. According to the Small Business
Administration regulations, most of them would be classified as small
entities. The majority of these establishments currently utilize in
vitro relative potency tests to release serials of veterinary
biological products. Since potency testing is already required under
Sec. 113.5 of the regulations and since this rule does not require the
use of in vitro relative potency tests, any additional cost imposed by
the validity requirements specified in this rule should be minimal. In
the absence of a standard requirement prescribing a specific potency
test for inactivated products, the firms develop a potency test
suitable for their product, and designate such tests in the outline of
production that is filed with APHIS. Currently, firms are using host
animal tests, laboratory animal tests, and a variety of in vitro
immunoassays as potency tests for products. This rule does not restrict
the firm's discretion to choose the most appropriate test for its
product. The rule only prescribes validity requirements for in vitro
immunoassays for relative potency. The overall effect of this amendment
will be to standardize in vitro immunoassays that are used to determine
the potency of inactivated veterinary biological products.
Under these circumstances, the Administrator of the Animal and
Plant Health Inspection Service has determined that this action will
not have a significant economic impact on a substantial number of small
entities.
Executive Order 12372
This program/activity is listed in the Catalog of Federal Domestic
Assistance under No. 10.025 and is subject to Executive Order 12372,
which requires intergovernmental consultation with State and local
officials. (See 7 CFR part 3015, subpart V.)
Executive Order 12988
This final rule has been reviewed under Executive Order 12988,
Civil Justice Reform. It is not intended to have retroactive effect.
This rule would not preempt any State or local laws, regulations, or
policies, unless they present an irreconcilable conflict with this
rule. There are no administrative procedures which must be exhausted
prior to a judicial challenge to the provisions of this rule.
Paperwork Reduction Act
In accordance with the Paperwork Reduction Act of 1995 (44 U.S.C.
3501 et seq.), the information collection or recordkeeping requirements
included in this rule have been approved by the Office of Management
and Budget (OMB), and there are no new requirements. The assigned OMB
control number is 0579-0013.
Regulatory Reform
This action is part of the President's Regulatory Reform
Initiative, which, among other things, directs agencies to remove
obsolete and unnecessary regulations and to find less burdensome ways
to achieve regulatory goals.
List of Subjects
9 CFR Part 101
Animal biologics.
9 CFR Part 113
Animal biologics, Exports, Imports, Reporting and recordkeeping
requirements.
Accordingly, 9 CFR parts 101 and 113 are amended as follows:
PART 101--DEFINITIONS
1. The authority citation for part 101 continues to read as
follows:
Authority: 21 U.S.C. 151-159; 7 CFR 2.22, 2.80, and 371.2(d).
2. Section 101.5 is amended by adding new paragraphs (o), (p), (q),
and (r) to read as follows:
Sec. 101.5 Testing terminology.
* * * * *
(o) Master reference. A Master Reference is a reference whose
potency is correlated, directly or indirectly, to host animal
immunogenicity. The Master Reference may be used as the working
reference in in vitro tests for relative potency. The Master Reference
may also be used to establish the relative potency of a serial of
product used in requalification studies and to establish the relative
potency of working references. The preparation of a Master Reference as
described in a filed Outline of Production may be:
(1) A completed serial of vaccine or bacterin prepared in
accordance with a filed Outline of Production;
(2) A purified preparation of a protective immunogen or antigen; or
(3) A nonadjuvanted harvested culture of microorganisms.
(p) Working reference. A Working Reference is the reference
preparation that is used in the in vitro test for the release of
serials of product. Working References may be:
(1) Master References; or
(2) Serials of product that have been prepared and qualified, in a
manner acceptable to Animal and Plant Health Inspection Service for use
as reference preparations.
(q) Qualifying serial. (1) A serial of biological product used to
test for immunogenicity when the Master or Working Reference is a
purified antigen or nonadjuvanted harvest material. Qualifying serials
shall be produced in accordance with the filed Outline of Production,
tested for immunogenicity in accordance with methods deemed appropriate
by the Animal and Plant Health Inspection Service, and have a geometric
mean relative potency, when compared to the Master Reference, of not
greater than 1.0 as established by: independent parallel line assays
with five or more replicates; or other valid assay methods for
determining relative antigen content which demonstrate linearity,
specificity, and reproducibility at least equivalent to the parallel
line assay and are acceptable to the Animal and Plant Health Inspection
Service.
(2) Qualifying serials used to requalify or extend the dating
period of a Master Reference shall be determined to be immunogenic in
accordance with methods deemed appropriate by the Animal and Plant
Health Inspection Service as provided in paragraph (a)(1) of this
section, and, in addition, shall be within their permitted dating
period and have been prepared in accordance with the production method
described in the currently filed Outline of Production.
(r) Immunogenicity. The ability of a biological product to elicit
an immune response in animals as determined by test methods or
procedures acceptable
[[Page 19038]]
to the Animal and Plant Health Inspection Service.
PART 113--STANDARD REQUIREMENTS
3. The authority citation for part 113 continues to read as
follows:
Authority: 21 U.S.C. 151-159; 7 CFR 2.22, 2.80, and 371.2(d).
4. Section 113.8 is amended as follows:
a. The section heading is revised to read as set forth below.
b. Paragraph (a) is revised to read as set forth below.
c. Paragraph (b) introductory text is revised to read as set forth
below.
d. Paragraph (b)(5) is revised to read as set forth below.
e. Paragraph (c) is redesignated as paragraph (e) and new
paragraphs (c) and (d) are added to read as set forth below.
f. In redesignated paragraph (e), in the introductory text, the
reference to ``paragraph (b)'' is removed and ``paragraphs (b) and
(c)'' are added in its place. In redesignated paragraph (e)(4), the
reference to ``paragraphs (c)(1),'' is removed and ``paragraphs
(e)(1),'' is added in its place.
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 Secs. 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:
(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:
* * * * *
(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 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.
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(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
[[Page 19039]]
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 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.
* * * * *
Done in Washington, DC, this 15th day of April 1997.
Donald W. Luchsinger,
Acting Administrator, Animal and Plant Health Inspection Service.
[FR Doc. 97-10100 Filed 4-17-97; 8:45 am]
BILLING CODE 3410-34-P
