Source: CNN and BBC (including justification)Meanwhile, Pfizer said it did not have data to demonstrate that just a single dose of its vaccine would provide protection against the disease after more than 21 days.
"Pfizer and BioNTech's Phase 3 study for the Covid-19 vaccine was designed to evaluate the vaccine's safety and efficacy following a 2-dose schedule, separated by 21 days," Pfizer said in a statement on Thursday. "There are no data to demonstrate that protection after the first dose is sustained after 21 days."
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