| Active Not Recruiting | A Study to Learn About How Well Yearly Updates to the COVID-19 Vaccine Work to Protect People From COVID-19 an NCT06923137 | Pfizer | — |
| Unknown | UNAIR Inactivated COVID-19 Vaccine as Homologue Booster (Immunobridging Study) NCT06259578 | Dr. Soetomo General Hospital | EARLY_Phase 1 |
| Unknown | UNAIR Inactivated COVID-19 Vaccine INAVAC as Heterologue Booster (Immunobridging Study) in Adolescent Subjects NCT06272253 | Dr. Soetomo General Hospital | EARLY_Phase 1 |
| Completed | Effectiveness of BNT162b2 Formulations Using State Vaccine Registry and Insurance Claims Data NCT06199934 | Pfizer | — |
| Completed | PREPARE-iVAC Trial NCT05924685 | University Medical Center Groningen | Phase 4 |
| Unknown | INAVAC Vaccine Phase III (Immunobridging Study) in Healthy Population Aged 12 to 17 Years Old NCT06282692 | Dr. Soetomo General Hospital | Phase 3 |
| Active Not Recruiting | Bringing Optimised COVID-19 Vaccine Schedules To ImmunoCompromised Populations (BOOST-IC): an Adaptive Randomi NCT05556720 | Monash University | Phase 3 |
| Unknown | UNAIR Inactivated COVID-19 Vaccine as Heterologue Booster (Immunobridging Study) NCT05918939 | Dr. Soetomo General Hospital | EARLY_Phase 1 |
| Completed | Improving Pediatric COVID-19 Vaccine Uptake Using an mHealth Tool NCT05386355 | IDeA States Pediatric Clinical Trials Network | N/A |
| Active Not Recruiting | Getting to Yes, Michigan! (G2YMI) NCT05096260 | University of Michigan | N/A |
| Unknown | UNAIR Inactivated COVID-19 Vaccine Phase III (Immunobridging Study) NCT05508477 | Dr. Soetomo General Hospital | Phase 3 |
| Unknown | Variables Influencing Anti-COVID-19 Vaccinations Around the World: an Analysis Conducted on Aggregated Data So NCT05471635 | Alberto Peano | — |
| Completed | Intradermal Tozinameran for Patients With Immune-mediated Dermatologic Diseases NCT05406908 | Mahidol University | Phase 4 |
| Unknown | Randomized, Single-blinded, Multicenter Trial Comparing the Immune Response to a 2nd Booster Dose of COVID-19 NCT05405283 | Assistance Publique - Hôpitaux de Paris | Phase 3 |
| Completed | Effect of a Third COVID-19 Booster Among Health Care Workers NCT05373459 | Hong Kong Sanatorium & Hospital | — |
| Unknown | COVID-19 Booster Dose Reminder/Recall for Adolescents NCT05571657 | Marshfield Clinic Research Foundation | N/A |
| Unknown | Platform Trial to Compare Homologous Boost of Authorized COVID-19 Vaccines and Heterologous Boost With UB-612 NCT05293665 | Vaxxinity, Inc. | Phase 3 |
| Terminated | Safety, Reactogenicity and Immunogenicity of a Novel MVA-SARS-2-ST Vaccine Candidate NCT05226390 | Hannover Medical School | Phase 1 |
| Unknown | Effectiveness of Vaccination Against COVID-19 in Brazil: Case-Control Study NCT05621928 | The Immunobiological Technology Institute (Bio-Manguinhos) / Oswaldo Cruz Foundation (Fiocruz) | — |
| Unknown | Effectiveness of COVID-19 Vaccine in Hematopoietic Stem Cell Transplant Patients NCT05185817 | Tehran University of Medical Sciences | Phase 2 |
| Unknown | Combined Immunization of COVID-19 Inactivated Vaccine With QIV and PPV23 NCT05298800 | Centers for Disease Control and Prevention, China | Phase 4 |
| Completed | The ARCT-154 Self-Amplifying RNA Vaccine Efficacy Study (ARCT-154-01) NCT05012943 | Vinbiocare Biotechnology Joint Stock Company | Phase 2 / Phase 3 |
| Unknown | Strategies for Combining the First Component of Sputnik V With Other Adenoviral or mRNA-based Vaccines. NCT05027672 | Ministerio de Salud de Ciudad Autónoma de Buenos Aires | Phase 2 |
| Unknown | Study to Evaluate the Immunogenicity and Safety of Heterologous SARS-CoV-2 Vaccine Schemes in an Elderly Popul NCT04983537 | Ministerio de Salud de Ciudad Autónoma de Buenos Aires | Phase 2 |
| Completed | Study to Evaluate the Immunogenicity and Safety of Heterologous SARS-CoV-2 Vaccine Schemes NCT04962906 | Ministerio de Salud de Ciudad Autónoma de Buenos Aires | Phase 2 |
| Unknown | Comparative Evaluation of Covid-19 Vaccines Response NCT04895007 | Karamanoğlu Mehmetbey University | — |
| Completed | Immune Response to Anti COVID-19 Vaccine in Immunocompromised Patients: a Cohort Study NCT04888793 | Pontificia Universidad Catolica de Chile | — |
| Completed | Response of Haemodialysis Patients to BNT162b2 mRNA Cov-19 Vaccine NCT04881396 | Hospices Civils de Lyon | — |
| Unknown | The Future of Viral Communications: Video-Based Health Promotion Strategies for COVID-19 Vaccinations NCT04876885 | McMaster University | N/A |
| Unknown | Follow-up of COVID-19 Vaccine Response in Strasbourg University Hospitals NCT04852835 | University Hospital, Strasbourg, France | — |
| Unknown | Analysis of Immunogenicity, Safety and Efficacy of COVID-19 Vaccines in Immunosuppressed Individuals NCT04871165 | Vilnius University | — |
| Completed | COVID-19 Serologies Among Healthcare Workers at CHSD (SERO2) NCT06989307 | Centre Hospitalier de Saint-Denis | — |
| Completed | Impact of Maternal COVID-19 Vaccines on Breast Milk NCT04751734 | Institute of Agrochemistry and Food Technology, National Research Council | — |
| Unknown | Immunologic Responses to Single and Double Doses of COVID-19 Vaccines in Egyptians NCT04706143 | Assiut University | — |
| Unknown | The COVID-19 Back-to-Normal Study: Analysis of Multiple Outcomes NCT04832932 | Mebo Research, Inc. | — |
| Completed | Improving COVID-19 Vaccine Uptake in Nursing Homes NCT04732819 | Brown University | N/A |
| Completed | COVID-19 Quantitative Antibody Titers & Booster Vaccinations NCT05104359 | Epividian | — |
| Unknown | Effectiveness and Safety of the Inactivated COVID-19 Vaccine in Thousands of Patients With Autoimmune Diseases NCT05831826 | Zhejiang Chinese Medical University | — |