Global regulators agree on way forward to adapt COVID-19 vaccines to emerging variants
International regulators have published a report today highlighting the outcomes of their discussions on COVID-19 vaccines and the need for and strategy to update their composition based on the emerging evidence on coronavirus SARS-CoV-2 variants and lessons learned from previous vaccine updates. The workshop, co-chaired by the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA), was organised under the umbrella of the International Coalition of Medicines Regulatory Authorities (ICMRA) and took place on 8 May 2023.
Currently authorised vaccines continue to be effective at preventing hospitalisation, severe disease and death due to COVID-19. However, protection against infection wanes over time and as new SARS-CoV-2 variants emerge. Preliminary data show that COVID-19 vaccines adapted to the currently circulating strains improve immunity to recently emerged variants, such as XBB descendent lineages.
Meeting participants discussed the available scientific evidence on epidemiology, seroprevalence (i.e. the number of persons in a population who test positive for a specific disease based on blood serum measurements) and vaccine performance, and key regulatory considerations related to the adaptation of authorised or new COVID-19 vaccines against emerging coronavirus variants. There is a broad agreement that vaccine formulations for the upcoming winter season in the northern hemisphere should include only one virus strain and be based on the XBB family of Omicron subvariants (such as XBB.1.5). International regulators also highlighted that such monovalent vaccines could be used for both booster and primary vaccinations (the latter, for example, only in young children below 4-5 years of age). They noted that only data on manufacturing and quality of the vaccine and laboratory data would be required for the authorisation or approval of strain changes for the already authorised COVID-19 vaccines, provided that post-authorisation data regarding vaccine quality, effectiveness, immunogenicity and safety data are collected.
The meeting built on the experience and knowledge gained from a series of ICMRA workshops on COVID-19 vaccine development and virus variants held over the past three years. Participants included representatives of international regulators as well as experts from the World Health Organization (WHO).
The workshop was co-chaired by Peter Marks, Director of the Center for Biologics Evaluation and Research (CBER) at US FDA, and Marco Cavaleri, Head of Health Threats and Vaccines Strategy at EMA.