Publication date: Dec 19, 2025
Immunization of nave mice and mice previously immunized with SARS-CoV-2 variants with monovalent LP. 8.1 induced high neutralizing antibody titers against the homologous antigen, JN. 1, NB. 1.8. 1 and XFG. In May 2025, the TAG-CO-VAC recommended that monovalent JN. 1 or KP. 2 remain appropriate vaccine antigens and that monovalent LP. 8.1 is a suitable alternative vaccine antigen. Based on these evaluations, WHO advises vaccine manufacturers and regulatory authorities on the implications for future updates to COVID-19 vaccine antigen composition. Multiple manufacturers (using mRNA or recombinant protein-based vaccines) have updated COVID-19 vaccine antigen composition to monovalent JN. 1 lineage formulations (JN. 1, KP. 2 or LP. 8.1). Data on the immune responses following JN. 1 descendent lineage infection or monovalent JN. 1, KP. 2 or LP. 8.1 vaccination are largely restricted to neutralizing antibodies. As observed in mice, post-monovalent JN. 1 vaccination neutralizing antibody titers against XFG and BA. 3.2 were lower than those against the homologous JN. 1 antigen. Prior to each meeting, the TAG-CO-VAC will publish an update to the statement on the types of data requested to inform COVID-19 vaccine antigen composition deliberations.
| Concepts | Keywords |
|---|---|
| Australia | Antigen |
| Genetic | Circulating |
| Influenza | Co |
| Protectionrelative | Cov |
| Covid | |
| Jn | |
| Lp | |
| Neutralizing | |
| Sars | |
| Tag | |
| Vac | |
| Vaccination | |
| Vaccine | |
| Vaccines | |
| Variants |
Semantics
| Type | Source | Name |
|---|---|---|
| disease | MESH | Influenza |
| disease | MESH | XFG |
| disease | MESH | death |
| disease | MESH | infection |
| disease | MESH | included |
| pathway | REACTOME | SARS-CoV-2 Infection |
| disease | MESH | COVID-19 |