Covid-19: Pfizer-BioNTech, Moderna expect data on shot protection against new variant soon

"A booster dose of an authorized vaccine represents the only currently available strategy for boosting waning immunity," Moderna said in the statement.

Escape variants are those that elude the targeted immune response brought about by vaccination. Pfizer and BioNTech would be able to redesign their shot within six weeks and ship initial batches within 100 days, BioNTech added.

BioNTech ADRs gained 14.2% to close at $348 on Friday and Pfizer shares rose 6.1% to end at $54. Moderna gained 20.6% to close at $329.63.

Global authorities reacted with alarm on Friday to the new variant, with the EU and Britain among those tightening border controls as scientists sought to find out if the mutation was vaccine-resistant. 

Pfizer and BioNTech have already created versions of their established mRNA-based vaccine - based on the original virus found in the Chinese city of Wuhan - to target the so-called Alpha and Delta variants, with clinical trials ongoing.

Those efforts are not meant to yield commercial products; the exercise is carried out to establish a routine with regulators that will help speed up any future vaccine relaunch.

Analysts at Evercore ISI said data from Qatar on another recent variant showed a high level of initial efficacy by current vaccines that faded significantly four months after dosing.

Johnson and Johnson said it is also closely monitoring emerging strains of COVID-19 and is testing the effectiveness of its shot against the new variant.