Britain, Canada will fast-track modified COVID-19 vaccines to tackle variants

Woman receiving COVID-19 vaccination
A woman receives a COVID-19 shot in London.
(Frank Augstein / Associated Press)

Regulators in Britain, Canada, and three other countries plan to fast-track the development of modified COVID-19 vaccines to ensure that drugmakers are able to move swiftly in targeting emerging variants of the coronavirus.

Previously authorized vaccines that are adjusted to target new variants “will not need a brand new approval or ‘lengthy’ clinical studies,” Britain’s Medicines and Healthcare Products Regulatory Agency, or MHRA, said in a statement.

“The clear goal is that future vaccine modifications that respond to the new variants of coronavirus can be made available in the shortest possible time to U.K. recipients without compromising at any stage on safety, quality or effectiveness,” Dr. June Raine, the head of the agency, told reporters.


The new guidance on fast-tracking is based on the model already used to tweak the seasonal flu vaccine to keep up with annual changes in the virus, and was issued jointly by regulators in Britain, Canada, Australia, Singapore and Switzerland. The U.S. Food and Drug Administration and European Medicines Agency have issued similar guidance.

Under the new rules, developers will be required to provide “robust evidence” that modified COVID-19 vaccines produce a strong immune response to the variant, as well as data showing they are safe and meet quality standards.

This means that developers will be required to carry out small-scale trials on a few hundred people, rather than the trials in tens of thousands of individuals that were required for initial approval, said Dr. Christian Schneider, the MHRA’s chief scientific officer.

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“I’d like to emphasize that, to date, we don’t have evidence that the vaccines in use in the U.K. are significantly lacking in effectiveness,” Raine said.

The announcement comes amid concerns that the coronavirus may mutate to create new versions that are resistant to existing vaccines. Britain has banned direct flights from 33 countries in an effort to prevent variants discovered in Brazil and South Africa from spreading.

Vaccine-makers have already been developing booster shots to target the new variants.

Moderna said Feb. 24 that it had shipped a variant-specific vaccine candidate to the U.S. National Institutes of Health for review.