EMA Issues New Guidance for Variant-Modified COVID-19 Vaccines

The European Medicines Agency (EMA) has issued new guidance outlining requirements for drug manufacturers that modify their COVID-19 vaccines to protect against several emerging variants to SARS-CoV-2.

EMA said it assumes new versions of the vaccines — targeting variants from Brazil, the UK and South Africa — would largely rely on the same technology and platform as their parent vaccines, with a new regulatory focus on triggering an immune response in the body. Large-scale safety and efficacy studies are not required, but EMA recommends conducting at least one clinical trial for participants who have not been vaccinated and have never been infected with SARS-CoV-2.

“A small group of [participants] should be randomly selected to receive either the parent or the variant vaccine,” EMA says. “This ‘bridging study’ is intended to gather evidence to demonstrate that the immune response, measured as neutralizing antibodies, triggered by the variant vaccine against the variant virus is of the same magnitude as the immune response elicited by the parent vaccine against the parent virus.”

The EU agency added that in the event vaccination with the parent vaccine is no longer feasible, a comparison between immune responses triggered by vaccination with the variant vaccine against the variant strain and prior data on the immune response with the parent vaccine against the parent strain would suffice.

Manufacturers should also study the efficacy of the variant vaccine when given as a single dose, as a booster, to participants previously vaccinated with the parent vaccine, EMA says. “The immune response induced by one dose of the variant vaccine against the variant strain should be compared with the immune response recorded during clinical trials with the parent vaccine against the parent strain of the virus.”

Although no further laboratory studies are required to support the development of variant vaccines, EMA said it expects variant vaccines to be produced by the same manufacturer and in line with processes and controls used for the parent vaccine. “The manufacturer will need to generate data that show that the quality of the variant vaccine complies with the standards set for the parent vaccine,” the agency said. “In the case of a multivalent vaccine — one that contains different viral variant strains — additional evidence may be required to ensure the quality of the active substances and the finished product.”

Read the EMA guidance here: www.fdanews.com/02-25-21-EMA.pdf.