Review of animal use requirements in WHO biologics guidelines – database of suggested guideline revisions

Original text

Each final lot should be tested for unexpected toxicity (sometimes called abnormal toxicity) using a general safety (innocuity) test approved by the national regulatory authority. This test may be omitted for routine lot release once consistency of production has been well established to the satisfaction of the national regulatory authority and when good manufacturing practices are in place. Each lot, if tested, should pass a test for general safety.

New text

Original text

The NIH test as described in Laboratory techniques in rabies (10) should be used to evaluate consistency of production of the vaccine in question. This should also be used to test product stability for the purpose of establishing shelf life as well as to calibrate reference preparations. In this test mice are immunized and subsequently challenged with rabies virus. The test is conducted by vaccinating groups of mice, on two occasions, 7 days apart, with dilutions of an appropriate reference material calibrated against the International Standard for Rabies Vaccine the and vaccine being tested.

New text

Currently, in vitro assays (e.g. ELISA) have been developed or are under development and may be appropriate as a replacement to the in vivo assay for determination of potency. A quantitative in vitro test, approved by the NRA and using well-characterized antibodies, should be performed on each final vaccine lot. In vitro potency assays are preferred, however if an in vivo assay is carried out, it must be scientifically justified and should be approved by the NRA.

Original text

Each final lot should be tested for pyrogenic substances. The test should be
approved by the national regulatory authority.

New text

The need for pyrogenicity testing should be assessed during the manufacturing development process and be re-evaluated following any significant changes in the production process or relevant reported production inconsistencies that may influence pyrogenicity. A risk-based approach should be implemented which is suitable to the manufacturing process and the product depending on the potential presence of endotoxins and non-endotoxin pyrogens. The endotoxin content of the final product should be determined using a suitable in vitro assay, such as the recombinant factor C (rFC) or limulus/tachypleus amoebocyte lysate (LAL/TAL) tests. The rFC method is strongly recommended due to concerns over the impact on the sustainability of limulus stocks. The endotoxin content should be consistent with levels found to be acceptable in final product lots used in clinical trials and within the limits agreed upon with the NRA. A monocyte activation test (MAT) may be used for pyrogen testing after a product-specific validation. The use of the rabbit pyrogen test should be avoided due to its inherent variability, high retesting rates, and interspecies differences in pyrogenic responses as compared to humans.

Original text

A sample of the virus suspension should be tested for the presence of adventitious agents pathogenic to mice by intracerebral inoculation of 0.01 ml and intraperitoneal inoculation of at least 0.1 ml into at least 10 suckling mice. The mice should be less than 24 hours old and originate from more than one litter. They should be observed daily for at least 14 days. All mice that die within the first 24 hours following inoculation or that show signs of illness should be examined for evidence of viral infection.

New text

A strategy for testing adventitious viruses in vaccines must be developed based on a risk assessment. Relevant culture methods and/or specific molecular biology or broad molecular methods should be part of the overall testing package with the agreement of the NRA. In vivo tests may only be used if the risk assessment indicates that this test provides an additional risk mitigation taking into account the overall testing package.

Original text

A sample of the virus suspension should be tested for the presence of adventitious agents pathogenic to mice by intracerebral inoculation of 0.03 ml, intraperitoneal inoculation of at least 0.25 ml, and inoculation of 0.01 ml into the footpad in at least 20 adult mice, each weighing 15–20 g. The mice should be observed for at least 4 weeks. All mice that die within the fi rst 24 hours of inoculation or that show signs of illness should be examined for evidence of viral infection.

New text

A strategy for testing adventitious viruses in vaccines must be developed based on a risk assessment. Relevant culture methods and/or specific molecular biology or broad molecular methods should be part of the overall testing package with the agreement of the NRA. In vivo tests may only be used if the risk assessment indicates that this test provides an additional risk mitigation taking into account the overall testing package.

Original text

Moreover, whenever in vivo tests are performed during vaccine development or manufacturing, it is desirable for ethical reasons to apply the 3Rs principles (Replacement, Reduction, Refinement) to minimize the use of animals where scientifically appropriate (97).

New text

Moreover, whenever in vivo tests are performed during vaccine development or manufacturing, it is desirable for both scientific and ethical reasons to apply the 3Rs principles (Replacement, Reduction, Refinement) to minimize the use of animals where scientifically appropriate (97).

Original text

Each virus MS lot should also be tested in animals if the risk assessment indicates that this test provides a risk mitigation taking into account the overall testing package (103). The animals used might include guinea-pigs, adult mice and suckling mice.

New text

A strategy for testing adventitious viruses in vaccines must be developed based on a risk assessment. Relevant culture methods and/or specific molecular biology or broad molecular methods should be part of the overall testing package with the agreement of the NRA. In vivo tests may only be used if the risk assessment indicates that this test provides an additional risk mitigation taking into account the overall testing package.

Original text

As outlined in Part B below, studies should, when relevant, be performed in animals to determine that the MS virus displays attenuating features which are maintained throughout subsequent vaccine process steps. For certain candidate vaccines it may be required to test at least once during nonclinical development for these features in a relevant animal model. For an MS virus to be identified as attenuated the criteria for determining attenuation should be clearly defined. The NRA may decide that such testing does not need to be repeated each time a new WS lot is derived.

New text

Original text

Each recombinant baculovirus seed should be tested in cell cultures for adventitious agents appropriate to the origin and passage history of the seed baculovirus.

New text

A strategy for testing adventitious viruses in vaccines must be developed based on a risk assessment. Relevant culture methods and/or specific molecular biology or broad molecular methods should be part of the overall testing package with the agreement of the NRA. In vivo tests may only be used if the risk assessment indicates that this test provides an additional risk mitigation taking into account the overall testing package.

Original text

For replicating vectors, in vivo growth characteristics in a suitable animal model may also be informative and should be performed if justified.

New text

For replicating vectors, growth characteristics in a suitable model may also be informative and should be performed if justified.