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Variation Type A

Variation Type A


Approval by the responsible national regulatory authority (NRA) and by WHO is required before implementation of variations categorized as Type A, for lots to be supplied through UN agencies. However, variations may be approved based on the NRA report provided that:

  • the vaccine has an established data sharing agreement with the NRA of record as part of a streamlined procedure for prequalification
  • variation assessment information from the responsible NRA is supplied.

As a general rule, the time required by WHO to evaluate a Type A variation should not exceed 90 days, with manufacturers granted a maximum of a further 30 days to provide any supplementary information requested by WHO.

Documents to be submitted

The following documents should be provided with each application for a variation Type A:

  • a covering letter (see template)
  • a completed variation form (see application form)
  • if a variation is the consequence of or related to another variation, a description of the relationship between these variations should be provided in the appropriate section of the application form
  • documentary evidence that the variation meets the conditions referred to in Guidance on Variations to a Prequalified Vaccine and that relevant supportive documentation is available, as referred to in this document
  • where relevant, a side-by-side comparison of the previously approved product and the proposed information
  • documents listed in the relevant section of Appendix 2 (Manufacturing and Quality Control) or Appendix 3 (Efficacy and Safety) of Guidance on Variations to a Prequalified Vaccine, as appropriate.

WHO shall inform the manufacturer and the NRA of the concerned country about the approval or rejection of the variation (including the rationale for a negative outcome).

It may be the case that a Type A variation may imply modifications to labeLling or package leaflet of the vaccine, in which case the applicant should submit updates – with the corresponding translations – of the product information texts according to the current prequalification procedure.

Where to submit a Type A variation application

The changes included in this reporting category should be submitted by the vaccine manufacturer  by email to: vaccprequalification@who.int