According to WHO guidelines based on several co-administration studies of COVID-19 vaccines and inferred from co-administration studies of other adult vaccines, COVID-19 vaccines may be given concomitantly (during the same visit), or any time before or after, other adult vaccines including live attenuated, inactivated, adjuvanted, or non-adjuvanted vaccines.

When administered concomitantly, the vaccines should be injected using individual syringes, in separate sites, preferably different extremities.

For children and adolescents, evidence from co-administration studies is currently insufficient. Nevertheless, the same principle as with adults can be applied. Each opportunity or visit to a health care provider should be used to administer missing vaccines to get maximum protection.