WHO Requests Data Ahead of December 2026 COVID-19 Vaccine Composition Review

On 27 October 2026, the World Health Organization (WHO) issued a statement outlining the types of data requested to inform the December 2026 deliberations of the Technical Advisory Group on COVID-19 Vaccine Composition (TAG-CO-VAC). The group continues to monitor the genetic and antigenic evolution of SARS-CoV-2 variants, immune responses to infection and vaccination, and the performance of COVID-19 vaccines against circulating variants, advising vaccine manufacturers and regulatory authorities on the implications for future updates to vaccine antigen composition. A statement on COVID-19 vaccine antigen composition, with an accompanying data annex, will be published after the December meeting. The request updates a similar statement issued in March 2026.

The requested data cover the genetic evolution of SARS-CoV-2 and the antigenic characteristics of previously and currently circulating variants, analysed through one-way and two-way neutralization tests using animal antisera and human sera; immunogenicity data assessing the breadth and durability of immune responses; and vaccine effectiveness estimates for currently approved vaccines that control for time since vaccination and provide variant-specific estimates across outcomes ranging from any infection to severe disease. Manufacturers are asked to share animal and human data on the breadth and durability of responses elicited by authorized vaccines and any candidates in development, together with observational epidemiological data on their effectiveness. Key antisera and antigens of interest for the December meeting include LP.8.1, NB.1.8.1, XFG (including recent sublineages ST.1 and SW.2.1), BA.3.2, PQ.16.1.1 and potentially emerging variants such as PJ.2.1, while relative vaccine effectiveness estimates are requested for monovalent XFG, LP.8.1, JN.1 and KP.2 compositions.

For vaccine manufacturers, the statement is effectively a workplan: data packages generated and shared ahead of the meeting can inform a composition decision that will define what updated products regulators expect in the next production cycle. For distributors, procurement agencies and immunization programme partners, a December 2026 decision signals potential antigen updates to authorized COVID-19 vaccines in the months that follow, which is worth tracking when drafting tender specifications, forecasting demand and planning shelf-life and cold-chain logistics. Submissions and enquiries are directed to the TAG-CO-VAC Secretariat.

Source: WHO, Types of data requested to inform December 2026 COVID-19 vaccine antigen composition deliberations, https://www.who.int/news/item/27-10-2026-types-of-data-requested-to-inform-december-2026-covid-19-vaccine-antigen-composition-deliberations