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Step 2.1 – Complete national regulatory processes
For new technologies, the ministry of health should work closely with the relevant government authorities, manufacturers and authorized service providers to meet the requirements of the national regulatory authority. Sufficient time must be allowed for review of the application and any supplementary evidence. Regulatory approval is generally provided for a specific test produced by a specific manufacturer, not for the class of the test. Approval of more than one test may improve access to tests and allow countries to choose between different tests based on test performance, as well as cost–effectiveness, feasibility and other operational aspects.
As an example, the regulatory pathway for approval of TBST will probably be the same as the one for TST materials. In many settings, because TB infection skin test material is injected, it is considered to be a medicine or a vaccine; therefore, the time to approval may be longer, with greater requirements for data (especially for safety), and the procedures for regulatory approval need to be initiated well in advance.
Step 2.2 – Determine importation requirements
National authorities should be consulted to determine relevant processes to be followed for importation of equipment and supplies for new tests. Early in the implementation process, countries should work closely with manufacturers and authorized providers of equipment and consumables to determine importation and registration as well as transportation and storage requirements, and to initiate country verifications, if required.
Step 2.3 – Conduct country validation and verification studies, as required
Validation studies are typically large-scale evaluations that measure the performance of the test, to determine whether it performs as expected under a setting’s implementation conditions or whether country-specific factors (e.g. prevalence of different mutations or microorganism strains) cause performance to deviate substantially from the manufacturer’s results or other evaluation studies. Validation studies are an essential part of the WHO review process and the development of recommendations for the use of a new test. Once large-scale validation studies have been published and a test’s target performance characteristics have been established, countries that are implementing the method do not need to repeat such large-scale studies. Repeat validation should only be conducted if registration or importation regulations require it, because the efforts may use valuable limited testing resources and delay the implementation of the test.
Instead, implementing laboratories should conduct small-scale verification studies to demonstrate that they can achieve the same performance characteristics that were obtained during the validation studies when using the test as described in those validation studies, and establish that the method is suitable for its intended use in the population being tested. This usually involves testing a well-characterized panel of known positive and negative samples (in a blinded fashion), in line with requirements for national or international accreditation schemes. In addition, these studies may include prospectively testing the current gold standard and the new test in parallel on clinical specimens. Verification is also required before commencing testing of clinical specimens in cases where laboratories perform non-standard or modified methods, use tests outside their intended scope (e.g. on specimens for which the test has not been validated), or use methods developed in-house. These studies, in addition to testing a wellcharacterized panel of known positive and negative samples, may include prospectively testing the current gold standard and the new test in parallel on clinical specimens (65), or testing it in situations where a method has changed when compared with a previously completed validation (e.g. new versions) (66).
Countries must make their own determination on the need for validation or verification studies, based on national regulatory policies, guidelines and accreditation requirements.