Interim guidance, 26 October 2021 This interim guidance has been developed on the basis of the advice issued by the Strategic Advisory Group of Experts (SAGE) on Immunization at its meeting on 5 October 2021. SAGE said moderately and severely immunocompromised persons should be offered an additional dose of all WHO approved vaccines “since these individuals are less likely to respond adequately to vaccination following a standard primary vaccine series and are at high risk of severe COVID-19 disease.” People aged 60 and older who received the Sinovac and Sinopharm vaccines should get a third dose too, the experts added, though use of other vaccines may also be considered depending on supply and access. “When implementing this recommendation, countries should initially aim at maximizing 2-dose coverage in that population, and thereafter administer the third dose, starting in the oldest age groups”, they said. SAGE has also reviewed a vaccine developed by Indian company Bharat Biotech and will issue a policy recommendation after WHO greenlights it for emergency use.