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

Original text

The Identity of the Vi polysaccharide lot with an in-house standard Vi polysaccharide confoirming to the purity requirements of sections A.3.3.2 shall be established by immunoprecipitation.
Hyperimmune serum prepared by multiple intravenous injections of Citrobacter freudii, a non-pathological organism that has a Vi polysaccharide identical to that of S.typhi, has proven reliable

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An identification test shall be carried out using a suitable immunochemical method.

Original text

The identity of the final bulk shall be established by a serological assay based on immunoprecipitation.

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An identification test shall be carried out using a suitable immunochemical method.

Original text

An identity shall be performed by a serological method on at least on labbelled container.

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An identification test shall be carried out using a suitable immunochemical method.

Original text

Each final lot shall be tested for pyrogenicity by intravenous injection into rabbits. A test that has been found to be suitable for the current vaccine involves injection into the ear vein of rabbits of 1ml per kg of body weight of a dilution of vaccine containing 25ng per ml.

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 lot shall be tested for abnormal toxicity by the intraperitoneal injection of one human dose into each of five mice (weighing 17-22g) and at least one human dose into each of two guinea-pigs (weighing 250g.350g).

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Original text

The vaccine should be manufactured in such a way that reversion to toxicity does not occur during the defined shelf-life, provided that the vaccine is stored under the conditions recommended on the label. To confirm thatn the vaccine does not revert to toxicity during storage, the specific toxicity test described in Part A, section A.3.5.2.5, should be scheduled up until the expiry date as part of the stability studies. In addition, at the time of the expiry date, the vaccine should meet the requirements or acceptance limits for the final product in terms of sterility, potency,

New text

The vaccine should be manufactured in such a way that reversion to toxicity does not occur during the defined shelf-life, provided that the vaccine is stored under the conditions recommended on the label. To confirm that the vaccine does not revert to toxicity during storage, a Vero cell assay can be performed on the final purified bulk at time of the expiry date. If the production method removes the risk of reversion or historical data demonstrate a lack of reversion, this test is not required and should be omitted.

Original text

Harvests should be treated as potentially toxic, and subject to the appropriate safety restrictions until the detoxification has been shown to be complete by performance of a specific toxicity test (as detailed in section A.3.4.4) or any other suitably validated in vivo or in vitro method.
SMALL PRINT: Detoxification can be confirmed by subcutaneous inoculation of the toxin into guinea-pigs, or by intradermal injection into guinea-pigs or rabbits. A cell culture assay, such as the Vero cell assay, is also suitable.

New text

Detoxification should be confirmed using a suitable assay in agreement with the NRA. The Vero cell assay is highly sensitive and is considered superior to existing in vivo test methods. Once validated, in vitro assays should be used for batch release testing.

Original text

Each bulk purified toxoid should be tested for the presence of diphtheria toxin. The test may be performed in vivo using guinea-pigs or in vitro using a suitable cell culture assay, such as the Vero cell assay.
Some manufacturers carry out an alternative test for determining whether diphtheria toxin is present: they inject intradermally into rabbits or guinea-pigs at least 20 Lf of purified toxoid and observe the injection sites for specific erythema. Erythema with a diameter greater than 5 mm is typically considered to be positive.

New text

The absence of diphtheria toxin should be confirmed using a suitable assay in agreement with the NRA. The Vero cell assay is highly sensitive and is considered superior to existing in vivo test methods. Once validated, in vitro assays should be used for batch release testing

Original text

Each bulk purified toxoid should be tested to ensure that reversion to toxicity does not take place during storage. The test may be performed in vivo using guinea‑pigs or in vitro using a suitable cell culture assay, such as the Vero cell assay. The test employed should be approved by the NRA, and should be sufficiently sensitive to detect very small amounts of toxin. For the in vivo assay, the bulk purified toxoid should be diluted in order to obtain the same concentration and chemical environment as present in the final bulk vaccine
SMALL PRINT: For bulk toxoid that will be used in the preparation of more than one final-bulk formulation, the test should be performed using dilutions of the bulk toxoid that represent the lowest and highest concentrations of toxoid that will be present in the final formulations

New text

Each bulk purified toxoid should be tested to ensure that reversion to toxicity does not take place during storage. The test may be performed using a suitable cell culture assay, such as the Vero cell assay. The test employed should be approved by the NRA and should be sufficiently sensitive to detect very small amounts of toxin.

Original text

Each final bulk should be tested for specific toxicity in at least five guinea-pigs; each guinea-pig should weigh 250–350 g and not have been used previously for experimental purposes. Each guinea-pig is given a subcutaneous injection of a quantity equivalent to at least 5 SHDs, and is observed for 42 days

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