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

Original text

A potency test on the final bulk may be performed if it has not been performed on the final bulk. The required potency of the vaccine and the assay method shall be based on evidence submitted to prove efficacy in clinical trials and shall be approved by the national control authority.

New text

As suitable in vitro assays (e.g. ELISA) have been developed and are considered to be appropriate as a potency assay, a quantitative in vitro test, approved by the NRA or using appropriately characterized monoclonal antibodies or other affinity binders, should be performed on each final vaccine bulk or final lot. In vitro potency assays are preferred. However, an in vivo assay may be used if scientifically justified and approved by the NRA.

Original text

Each final lot shall be tested for the absence of abnormal toxicity in mice and guinea-pigs by atenteral injection. The test procedures shall be approved by the NCA

New text

Original text

Each final lot shall be tested for endotoxin. The test and limits shall be approved by the NCA

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

If serum is used for the propagation of mammalian cells, it should be tested to demonstrate freedom from bacteria, fungi and mycoplasmas, according to WHO requirements (11). Validated molecular tests for bovine viruses may replace the cell culture tests of bovine sera. As an additional monitor of quality, sera may be examined for freedom from phage and endotoxin. Gamma irradiation may be used to inactivate potential contaminant viruses.

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

Each final aqueous bulk should be tested for bacterial endotoxins. The endotoxin content should be consistent with levels found to be acceptable in vaccine lots used in clinical trials; the limits should be approved by the NRA.

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

If an in vivo potency test (i.e. immunogenicity) is used, this test may be performed on the final vaccine bulk. The methods for detecting antibodies to HBsAg and for analysing data should be approved by the NRA. The vaccine potency should be compared with that of a reference preparation and the NRA should determine the limits of potency and should approve the reference preparation used. If an in vitro potency test is performed, it should be performed on every lot of final vaccine. Methodological considerations regarding potency assays are outlined in Appendix 1.

New text

In vitro assays for antigen detection (e.g. ELISA) have been developed and are considered to be appropriate for the potency assay. A quantitative in vitro test, approved by the NRA and using appropriately characterized antibodies, should be performed using samples representative of each final vaccine bulk or final lot. If an in vivo assay is carried out instead of an in vitro assay, it must be scientifically justified and should be approved by the NRA.

Original text

An appropriate quantitative test for potency should be performed on samples that are representative of the final vaccine lot. The method and the analysis of data should be approved by the NRA. If an in vivo potency test is performed on the final bulk, the test on the final container may be omitted.

New text

An appropriate quantitative test for potency should be performed on samples that are representative of the final vaccine lot. The method and the analysis of data should be approved by the NRA.

Original text

Each final lot should be tested for the absence of abnormal toxicity in mice and guinea-pigs, using a general safety (innocuity) test approved by the NRA, and should pass the test. This test may be omitted for routine lot release once consistency of production has been established to the satisfaction of the NRA.

New text

Original text

The vaccine in the final container should be tested for pyrogenic activity, either by intravenous injection into rabbits or by a Limulus amoebocyte lysate test. Endotoxin content or pyrogenic activity should be consistent with levels found to be acceptable in vaccine lots used in clinical trials and approved by the NRA. The test is conducted until consistency of production is demonstrated to the satisfaction of the NRA.

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

Potency tests should reflect the activity of the vaccine and should be able to identify vaccines of low potency, which may be of reduced immunogenicity in humans. At the time when the WHO Requirements for recombinant hepatitis B vaccines were published, it was considered that assays that determine the HBsAg content of adjuvanted vaccines would be difficult to standardize. Therefore, it was proposed that immunogenicity in mice should form the basis for determining vaccine potency – by comparing the antibody response induced by the test and by the vaccine reference preparation – and that the specification for potency should be approved by the NRA.

New text

Potency tests should reflect the activity of the vaccine and should be able to identify vaccines of low potency, which may be of reduced immunogenicity in humans. Several manufacturers have developed and validated in vitro potency tests that are suitable for monitoring the product consistency of their individual vaccines. Where in vitro potency assays are not available or appropriate an immunogenicity assay in mice may be perfored.