* a history of laboratory-confirmed or clinically confirmed covid-19 infection prior to enrolment. * have previously already received one or two doses of any covid-19 vaccines except coronavac or bnt162b2, for example but not limited to bbibp-corv (inactivated vaccine, sinopharm), azd1222 (adenovirus vector-based vaccine, oxford/astrazeneca), sputnik v (adenovirus vector-based vaccine, gamaleya research institute) and ad26.cov2.s (adenovirus vector-based vaccine, johnson \& johnson). * individuals who report any medical condition, or as determined by a clinician, not suitable to receive mrna or inactivated covid-19 vaccines, including but not limited to allergies to the active substance or other ingredients of the vaccine. * currently with diagnosed medical conditions related to their immune system. * use of medication that impairs immune system in the last 6 months, except topical steroids or short-term oral steroids (course lasting ≤ 14 days). * administration of immunoglobulins and/or any blood products within 90 days preceding the planned administration of the study vaccines. * pregnancy, lactation or intention to become pregnant in the coming 3 months.

* a history of laboratory-confirmed or clinically confirmed covid-19 infection prior to enrolment. * have previously already received one or two doses of any covid-19 vaccines except coronavac or bnt162b2, for example but not limited to bbibp-corv (inactivated vaccine, sinopharm), azd1222 (adenovirus vector-based vaccine, oxford/astrazeneca), sputnik v (adenovirus vector-based vaccine, gamaleya research institute) and ad26.cov2.s (adenovirus vector-based vaccine, johnson \& johnson). * individuals who report any medical condition, or as determined by a clinician, not suitable to receive mrna or inactivated covid-19 vaccines, including but not limited to allergies to the active substance or other ingredients of the vaccine. * currently with diagnosed medical conditions related to their immune system. * use of medication that impairs immune system in the last 6 months, except topical steroids or short-term oral steroids (course lasting ≤ 14 days). * administration of immunoglobulins and/or any blood products within 90 days preceding the planned administration of the study vaccines. * pregnancy, lactation or intention to become pregnant in the coming 3 months.

- a history of laboratory-confirmed or clinically confirmed covid-19 infection prior to enrolment. - have previously already received one or two doses of any covid-19 vaccines except coronavac or bnt162b2, for example but not limited to bbibp-corv (inactivated vaccine, sinopharm), azd1222 (adenovirus vector-based vaccine, oxford/astrazeneca), sputnik v (adenovirus vector-based vaccine, gamaleya research institute) and ad26.cov2.s (adenovirus vector-based vaccine, johnson & johnson). - individuals who report any medical condition, or as determined by a clinician, not suitable to receive mrna or inactivated covid-19 vaccines, including but not limited to allergies to the active substance or other ingredients of the vaccine. - currently with diagnosed medical conditions related to their immune system. - use of medication that impairs immune system in the last 6 months, except topical steroids or short-term oral steroids (course lasting ≤ 14 days). - administration of immunoglobulins and/or any blood products within 90 days preceding the planned administration of the study vaccines. - pregnancy, lactation or intention to become pregnant in the coming 3 months.

- a history of laboratory-confirmed or clinically confirmed covid-19 infection prior to enrolment. - have previously already received one or two doses of any covid-19 vaccines except coronavac or bnt162b2, for example but not limited to bbibp-corv (inactivated vaccine, sinopharm), azd1222 (adenovirus vector-based vaccine, oxford/astrazeneca), sputnik v (adenovirus vector-based vaccine, gamaleya research institute) and ad26.cov2.s (adenovirus vector-based vaccine, johnson & johnson). - individuals who report any medical condition, or as determined by a clinician, not suitable to receive mrna or inactivated covid-19 vaccines, including but not limited to allergies to the active substance or other ingredients of the vaccine. - currently with diagnosed medical conditions related to their immune system. - use of medication that impairs immune system in the last 6 months, except topical steroids or short-term oral steroids (course lasting ≤ 14 days). - administration of immunoglobulins and/or any blood products within 90 days preceding the planned administration of the study vaccines. - pregnancy, lactation or intention to become pregnant in the coming 3 months.