The second dose of Pfizer and BioNTech’s coronavirus vaccine can be delayed for as long as six weeks if need be, World Health Organization advisers said Friday.
The Strategic Advisory Group of Experts on Immunization (SAGE), which advises WHO about vaccines, published interim guidance for the use of the Pfizer/BioNTech Covid vaccine under emergency use listing on Friday.
“WHO’s recommendation at present is that the interval between doses may be extended up to 42 days (6 weeks), on the basis of currently available clinical trial data,” the guidance document reads.
Pfizer’s vaccine is supposed to be given as two doses 21 days apart. On Friday, President-elect Joe Biden’s team said his administration would release all doses of coronavirus vaccines right away, instead of holding back half to ensure second doses are given on time, as the Trump administration has been doing.
If more information becomes available on longer intervals it may be revised and countries should ensure that any adjustments don’t affect the likelihood of receiving the second dose of vaccine, SAGE said.
Some countries face “exceptional circumstances of vaccine supply constraints combined with a high disease burden,” the panel said.