The agency said this “pragmatic approach” could be considered as a response to “exceptional epidemiological circumstances.”
“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,” it said, adding: “Should additional data become available on longer intervals between doses, revision of this recommendation will be considered.”
Hard-hit Britain, for example, has decided to delay for as much as 12 weeks — and data from that expansion could help contribute to possible revisions in the WHO recommendation, said WHO spokeswoman Dr. Margaret Harris.
In the recommendations, WHO added that countries seeking to extend the interval should make sure that vaccinated patients can still have access to a second dose.
The agency also said it also does not recommend COVID-19 vaccination of travelers unless they face high risks or qualify as priority cases.
WHO also said that symptomatic reinfection by the coronavirus within six months of a first infection is “rare,” so people who have had the illness within the previous six months “may delay vaccination until near the end of this period.”