INN for Variant COVID-19 Vaccine Active Substances
International Nonproprietary Names for Variant COVID-19 Vaccine Active Substances
1 April 2024
| Publication

Overview
Any change to the structure of a medicinal active substance will trigger a requirement for a new INN to be assigned. To highlight the close relationship of a variant COVID-19 vaccine substance to the original vaccine active substance, the INN of the variant active substance will be linked to the original INN (where one exists) by the addition of a short, random, two or three-letter syllable as a prefix to the original INN. This approach will be applied only to COVID-19 vaccine substances in which changes have been made to an original substance in order to direct the immune response to a VOC, i.e., a strain change, and where regulators are likely to authorise the variant vaccine by an abbreviated procedure. Any other change to the structure of the active substance, e.g., a change that alters the structure for other reasons such as improved antigen stability, or a change that improves expression or otherwise of a nucleic acid or vector, will be assigned a new unique alternative INN, not necessarily related to any preceding INN (where one exists). It is highlighted further that each active substance of a multivalent COVID-19 vaccine requires its own INN.
WHO Team
INN and Classification of Medical Products (INN)
Editors
Programme on International Nonproprietary Names (INN)
Number of pages
3
Reference numbers
WHO Reference Number: INN Working Document 21-520
Copyright
© World Health Organization 2024