The World Health Organization on Wednesday released its interim recommendations for using the Oxford/AstraZeneca Covid-19 vaccine in people 18 and older. The new guidance was developed based on advice issued by its Strategic Advisory Group of Experts (SAGE) on Immunization.
WHO recommends the vaccine is administered eight to 12 weeks apart.
WHO’s interim guidance states: “In light of the observation that two-dose efficacy and immunogenicity increase with a longer interdose interval, WHO recommends an interval of 8 to 12 weeks between the doses. If the second dose is inadvertently administered less than 4 weeks after the first, the dose does not need to be repeated. If administration of the second dose is inadvertently delayed beyond 12 weeks, it should be given at the earliest possible opportunity. It is recommended that all vaccinated individuals receive two doses.”
The Oxford/AstraZeneca vaccine is administered as an intramuscular injection and has an efficacy of 63.09% against symptomatic coronavirus infection, according to WHO’s interim recommendations.
WHO chief scientist Dr. Soumya Swaminathan said on Wednesday that SAGE had already made recommendations on the Pfizer/BioNTech and Moderna vaccines, and that in “in the coming weeks, you will see more recommendations coming out as we review the evidence from the different candidates.”