Key points:
- Vaccination remains an important public health countermeasure against COVID-19. As per the WHO Director General's standing recommendations for COVID-19 , Member States are recommended to continue to offer COVID-19 vaccination based on the recommendations of the WHO Strategic Advisory Group of Experts on Immunization (SAGE).
- SARS-CoV-2 continues to circulate and evolve with important genetic and antigenic evolution of the spike protein since the beginning of the COVID-19 pandemic.
- The objective of an update to COVID-19 vaccine antigen composition is to enhance vaccine-induced immune responses to circulating SARS-CoV-2 variants.
- The WHO TAG-CO-VAC advises retaining the use of a monovalent JN.1 lineage variant as the antigen in future formulations of COVID-19 vaccines.
- In accordance with WHO SAGE policy, vaccination should not be delayed in anticipation of access to vaccines with an updated composition; vaccination programmes can continue to use any available WHO emergency-use listed or prequalified COVID-19 vaccines.
The WHO Technical Advisory Group on COVID-19 Vaccine Composition (TAG-CO-VAC) continues to closely monitor the genetic and antigenic evolution of SARS-CoV-2 variants, immune responses to SARS-CoV-2 infection and COVID-19 vaccination, and the performance of COVID-19 vaccines against circulating variants. Based on these evaluations, WHO advises vaccine manufacturers and regulatory authorities on the implications for future updates to COVID-19 vaccine antigen composition. In April 2024, the TAG-CO-VAC recommended the use of a monovalent JN.1 lineage vaccine antigen as one approach to induce enhanced neutralizing antibody responses to JN.1 and its descendent lineages. Several manufacturers (using mRNA and recombinant protein-based vaccine platforms) have updated COVID-19 vaccine antigen composition to monovalent JN.1 lineage formulations (JN.1 or KP.2) and some of these have been approved for use by regulatory authorities. Previous statements from the TAG-CO-VAC can be found on the WHO website .
The TAG-CO-VAC reconvened on 10-12 December 2024 to review the genetic and antigenic evolution of SARS-CoV-2; immune responses to SARS-CoV-2 infection and/or COVID-19 vaccination; the performance of currently approved vaccines against circulating SARS-CoV-2 variants; and the implications for COVID-19 vaccine antigen composition.
Evidence reviewed
The published and unpublished evidence reviewed by the TAG-CO-VAC included: (1) SARS-CoV-2 genetic evolution with additional support from the WHO Technical Advisory Group on SARS-CoV-2 Virus Evolution
