Europe's medicines regulator said on Thursday it has issued new guidance for drug makers that modify their COVID-19 vaccines to protect against variants of the virus to speed up the approval process.
The move comes after variants first identified in Brazil, Britain and South Africa spread around the world, piling pressure on governments struggling to tame the pandemic which has killed more than 2.5 million people.
Drugmakers including Pfizer, Moderna and AstraZeneca have been testing their vaccines against several fast-spreading, more infectious variants of the coronavirus.
The European Medicines Agency (EMA) said it assumes any new variant vaccine would largely rely on the same technology as the parent vaccine, so regulatory focus would be on the immune response.
"Large-scale safety and efficacy studies are not needed," the EU regulator said, adding it recommends that at least one clinical trial would be conducted in subjects not vaccinated and never infected with SARS-Cov-2.
A small group of subjects should be randomly selected to receive either the parent or the variant vaccine as part of a bridging study to test the immune response, it said.
The EU agency said manufacturers should also study the efficacy of the variant vaccine when given as a single dose - as a booster - to people previously vaccinated with the parent vaccine.
The immune response induced by one dose of the variant vaccine against the variant strain should be compared with that recorded during clinical trials with the parent vaccine against the parent strain of the virus, it said.
No further laboratory studies are required to support the development of variant vaccines. It also expects the variant vaccines to be produced by the same manufacturer, and in line with processes and controls used for the parent vaccine, it said.
(Reporting by Yadarisa Shabong in Bengaluru and Emilio Parodi in Milan; Editing by Arun Koyyur and Josephine Mason)
