The second/third vaccine dose less than 4 weeks prior to vaccination with the third/fourth dose. Pregnant patients or women of childbearing potential (WOCBP) not on highly effective contraception (not acceptable methods: progesterone-only oral hormonal contraception, male/female condom without spermicide or cap, diaphragm or sponge with spermicide). Solid organ transplant recipients transplanted less than 6 months before the third dose vaccination. Serious side effect of previous SARS-CoV-2 vaccination. Allergic to any vaccine excipients. Acute febrile illness or acute infection. Received any vaccination against other infectious diseases within the last four weeks prior to the third dose. Have experienced breakthrough SARS-CoV-2 infection during or following primary vaccination. Participation in other vaccine studies.

The second/third vaccine dose less than 4 weeks prior to vaccination with the third/fourth dose. Pregnant patients or women of childbearing potential (WOCBP) not on highly effective contraception (not acceptable methods: progesterone-only oral hormonal contraception, male/female condom without spermicide or cap, diaphragm or sponge with spermicide). Solid organ transplant recipients transplanted less than 6 months before the third dose vaccination. Serious side effect of previous SARS-CoV-2 vaccination. Allergic to any vaccine excipients. Acute febrile illness or acute infection. Received any vaccination against other infectious diseases within the last four weeks prior to the third dose. Have experienced breakthrough SARS-CoV-2 infection during or following primary vaccination. Participation in other vaccine studies.

 Pregnant or lactating female patients.  Serious side effect of previous SARS-CoV-2 vaccination

 Pregnant or lactating female patients.  Serious side effect of previous SARS-CoV-2 vaccination