Participant must be >= 20 years of age inclusive, at the time of signing the informed consent. Participant who have received 2 doses of SARS-CoV-2 vaccine (Adults:only SPIKEVAX, Older adults: COMIRNATY or SPIKEVAX) and 6 months or more and 8 months or less after second dose.

Participant must be >= 20 years of age inclusive, at the time of signing the informed consent. Participant who have received 2 doses of SARS-CoV-2 vaccine (Adults:only SPIKEVAX, Older adults: COMIRNATY or SPIKEVAX) and 6 months or more and 8 months or less after second dose.