Global regulators agree on way forward to adapt Covid-19 vaccines to emerging variants

International regulators have published a report on the outcomes of their discussions on Covid-19 vaccines and the need for a strategy to update their composition based on the emerging evidence on coronavirus SARS-CoV-2 variants and lessons learned from previous vaccine updates, the European Medicines Agency (EMA) said.

The May 8 workshop, co-chaired by the EMA and the US Food and Drug Administration (FDA), was organised under the umbrella of the International Coalition of Medicines Regulatory Authorities (ICMRA).

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, the EMA said.

“Preliminary data show that Covid-19 vaccines adapted to the currently circulating strains improve immunity to recently emerged variants, such as XBB descendent lineages,” the agency said.

Meeting participants discussed the available scientific evidence on epidemiology, seroprevalence (that is, the number of people 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),” the EMA said.

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 four to five years of age).

They said 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 EMA said.

(Photo: Bulgaria’s Health Ministry)

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