(AGENPARL) - Roma, 23 Dicembre 2024 - (AGENPARL) – lun 23 dicembre 2024 No images? Click here https://hq_who_departmentofcommunications.cmail19.com/t/d-e-swurjl-iitylyihjr-k/
Monday, 23 December 2024
Media Advisory
23 December 2024
Statement on the antigen composition of COVID-19 vaccines [https://www.who.int/news/item/23-12-2024-statement-on-the-antigen-composition-of-covid-19-vaccines/]
Key points:Vaccination remains an important public health countermeasure against COVID-19. As per the WHO Director General’s standing recommendations for COVID-19 [https://www.who.int/publications/m/item/standing-recommendations-for-covid-19-issued-by-the-director-general-of-the-world-health-organization-(who)-in-accordance-with-the-international-health-regulations-(2005)-(ihr)], 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 [https://www.who.int/publications/i/item/WHO-2019-nCoV-Vaccines-SAGE-Prioritization-2023.1] (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 [https://extranet.who.int/prequal/sites/default/files/document_files/summary-status-of-covid-19-vaccines-within-who-eul-pq-evaluation-process-09-december-2024.pdf] COVID-19 vaccines.
The WHO Technical Advisory Group on COVID-19 Vaccine Composition [https://www.who.int/groups/technical-advisory-group-on-covid-19-vaccine-composition-(tag-co-vac)] (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 [https://www.who.int/news/item/26-04-2024-statement-on-the-antigen-composition-of-covid-19-vaccines] 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 [https://www.who.int/groups/technical-advisory-group-on-covid-19-vaccine-composition-(tag-co-vac)/about].
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 [https://www.who.int/groups/technical-advisory-group-on-virus-evolution] (TAG-VE); (2) Antigenic characterization of previous and emerging SARS-CoV-2 variants using virus neutralization tests with animal antisera and further analysis of antigenic relationships using antigenic cartography; (3) Immunogenicity data on the breadth of neutralizing antibody responses elicited by currently approved vaccine antigens against circulating SARS-CoV-2 variants using animal and human sera; (4) Preliminary immunogenicity data on immune responses following infection with circulating SARS-CoV-2 variants; (5) Available vaccine effectiveness (VE) estimates of currently approved vaccines during periods of circulation of XBB.1 and JN.1 lineages; and (6) Preliminary preclinical and clinical immunogenicity data on the performance of candidate vaccines with updated antigens shared confidentially by vaccine manufacturers with TAG-CO-VAC. Further details on the publicly available data reviewed by the TAG-CO-VAC can be found in the accompanying data annex. Unpublished and/or confidential data reviewed by the TAG-CO-VAC are not shown.
Summary of available evidence
The TAG-CO-VAC acknowledges several limitations of the available data:
Other approaches that demonstrate broad and robust neutralizing antibody responses against currently circulating JN.1 descendent lineage variants, such as vaccine antigens derived from more recent variants or alternative formulations, could also be considered.
As per the WHO Director General’s standing recommendations for COVID-19 [https://www.who.int/publications/m/item/standing-recommendations-for-covid-19-issued-by-the-director-general-of-the-world-health-organization-(who)-in-accordance-with-the-international-health-regulations-(2005)-(ihr)], Member States are recommended to continue to offer COVID-19 vaccination based on the recommendations of the WHO SAGE [https://www.who.int/publications/i/item/WHO-2019-nCoV-Vaccines-SAGE-Prioritization-2023.1]. 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 [https://extranet.who.int/prequal/sites/default/files/document_files/summary-status-of-covid-19-vaccines-within-who-eul-pq-evaluation-process-09-december-2024.pdf] COVID-19 vaccines.
Further data requested
Given the limitations of the evidence upon which the recommendations above are derived and the anticipated continued evolution of the virus, the TAG-CO-VAC strongly encourages generation of the following data (in addition to the types of data outlined in October 2024 [https://www.who.int/news/item/07-10-2024-types-of-data-requested-to-inform-december-2024-covid-19-vaccine-antigen-composition-deliberations]):
Immune responses and clinical endpoints (i.e. VE and/or comparator rates of infection and severe disease) in varied human populations who receive COVID-19 vaccines with a monovalent JN.1 or KP.2 vaccine antigen composition, across different vaccine platforms, as well as further clinical and laboratory data on the performance of all currently approved COVID-19 vaccines against emerging SARS-CoV-2 variants.Strengthened epidemiological and virological surveillance [https://www.who.int/publications/m/item/who-policy-brief-covid-19-surveillance], as per the Standing Recommendations for COVID-19 in accordance with the International Health Regulations (2005) [https://www.who.int/publications/m/item/standing-recommendations-for-covid-19-issued-by-the-director-general-of-the-world-health-organization-(who)-in-accordance-with-the-international-health-regulations-(2005)-(ihr)], to determine if emerging variants are antigenically distinct and able to displace circulating variants.Clinical evaluation of relevant new vaccine antigens derived from more recent variants.
As previously stated, the TAG-CO-VAC continues to encourage the further development of vaccines that may improve protection against infection and reduce transmission of SARS-CoV-2.
The TAG-CO-VAC will continue 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. The TAG-CO-VAC will also continue to reconvene every six months to evaluate the implications for COVID-19 vaccine antigen composition. At each meeting, recommendations to either maintain current vaccine composition or to consider updates will be issued.
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