The omicron variant of COVID-19 appears to be more infectious than the delta variant, and the high number of mutations on omicron means that all vaccines may be less effective, Moderna's CEO said Monday.
Stephane Bancel made the comments in an interview with CNBC.
"We believe this virus is highly infectious ... it seems to be much more infectious than delta," Bancel said. He estimated that any country that has accepted travelers from the southern African nations in the last 7 to 10 days now likely has the omicron variant present.
"It is highly possible that the efficacy of the vaccines -- all of them -- is going down," he added later.
Bancel said it will be at least a couple of weeks before the scientific community can get a better handle on the vaccine efficacy question, and anywhere from 2 to 6 weeks until they know whether omicron is more virulent than delta.
But Moderna is already working on boosters to address the new variant, he said. Within a couple of weeks, Bancel noted, the company will know which strategy to pursue -- a higher dose of current vaccines, or a booster, or a new vaccine to address the variant.
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Pfizer CEO Albert Bourla, appearing on CNBC later in the morning, echoed Bancel's sentiments.
“There are a lot of unknowns right now. Keep in mind we have been preparing for something like that for months," Bourla said of the possible emergence of a stronger variant of COVID.
"I think the results could be -- which we don’t know yet -- that the vaccines protect less," Bourla added.
He said Pfizer already started work last Friday on development of a new version of the vaccine that targets omicron, one that could be ready in about 100 days. (Pfizer also made new vaccines for the beta and delta variants, but they ultimately proved unnecessary.)