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Search / Trial NCT05109559

Ad26.COV2.S as a Heterologous Booster in Adults After Single- or Two-Dose of Inactivated COVID-19 Vaccine

Launched by MAHIDOL UNIVERSITY · Nov 4, 2021

Trial Information

Current as of August 02, 2025

Unknown status

Keywords

Sars Co V 2 Covid 19 Booster Heterologous

ClinConnect Summary

This clinical trial is studying a new booster vaccine called Ad26.COV2.S to see how safe it is and how well it works when given to adults who have already received either one or two doses of inactivated COVID-19 vaccines, like Sinovac or Sinopharm. The goal is to understand if this booster can help improve the immune response against COVID-19. The trial is currently looking for participants aged 18 and older who meet specific health criteria, such as being in good health and having documentation of their previous COVID-19 vaccinations.

If you choose to participate, you will receive either a half or full dose of the booster vaccine, and you will be monitored for any side effects and how well your immune system responds to the vaccine. It’s important to note that there are certain health conditions and recent vaccinations that may exclude you from participating, so your health status will be carefully reviewed. Overall, this study aims to provide valuable information about how well this booster can enhance protection against COVID-19 in adults who have previously been vaccinated with other types of COVID-19 vaccines.

Gender

ALL

Eligibility criteria

  • Inclusion Criteria:
  • Potential participants must meet all inclusion criteria to be enrolled and participate in the study, as follows:
  • 1. Adult male or female aged 18 years or more on the day of signing the ICF, confirmed by identification cards.
  • 2. Verified, documentation of past COVID-19 vaccination i. Study Part A: having completed the 2-dose homologous primary regimen (21 to 35 days apart) of inactivated COVID-19 vaccine of either Sinovac-Sinovac OR Sinopharm-Sinopharm ii. Study Part B: having received one dose of inactivated COVID-19 vaccine of either Sinovac or Sinopharm with the appropriate interval period
  • 3. Women of childbearing potential who are test negative with a highly sensitive urine pregnancy test at Visit 1, prior to study vaccine administration.
  • 4. Subject has provided written informed consent prior to performance of any study-specific procedures and is willing and has means to be contacted and to contact the investigator during the study.
  • 5. In the investigator's clinical judgment, the participant is in good health, or has stable and well-controlled medical conditions.
  • 6. Participant agrees to not donate bone marrow, blood, and blood products from the study vaccine administration until 3 months after receiving the study vaccine.
  • Exclusion Criteria:
  • Potential participants who meet any of the following exclusion criteria will be excluded from enrolment and participation in the study:
  • 1. The participant has a clinically significant acute illness (this does not include minor illnesses such as diarrhea or mild upper respiratory tract infection), or is a patient under investigation (PUI) or has a body temperature ≥38.0ºC (100.4°F) within 24 hours prior to the planned study vaccination. Assignment may be made at a later date is permitted at the discretion of the investigator. Please notify the Sponsor (or medical monitor) of this decision.
  • 2. Contraindication to Ad26.COV2.S according to labelling of the product. For example, if the participant has a known or suspected allergy or history of anaphylaxis or other serious adverse reactions to vaccines or their excipients (including specifically the excipients of the study vaccine;refer to the IB (IB Edition 5 Ad26.COV2.S 2021 and its addenda).
  • 3. Pregnant or planning to become pregnant within 3 months after study vaccine administration
  • 4. Participant has a history or current condition as follows
  • 1. Known documented history of COVID-19 infection prior to enrollment
  • 2. Any confirmed or suspected immunosuppressive or immunodeficient state.
  • 3. Heparin-induced thrombocytopenia or thrombosis in combination with thrombocytopenia.
  • 4. Acute polyneuropathy (e.g. Guillain-Barré syndrome).
  • 5. Capillary leak syndrome
  • 6. Contraindication to IM injections and blood draws e.g., bleeding disorders.
  • 7. An underlying clinically significant acute or chronic medical condition or physical examination findings for which, in the opinion of the investigator, participation would not be in the best interest of the participant (e.g., compromise the well being) or that could prevent, limit, or confound the protocol-specified assessments.
  • 8. Major psychiatric illness which in the investigator's opinion would compromise the participant's safety or compliance with the study procedures.
  • 5. If the participant received or plans to receive:
  • 1. Licensed live attenuated vaccines - within 28 days before or after planned administration of study vaccine.
  • 2. Other licensed (not live) vaccines - within 14 days before or after planned administration of study vaccine.
  • 3. Treatment with immunoglobulins (Ig) in the 3 months or exogenous blood products (autologous blood transfusions are not exclusionary) in the 4 months before the planned administration of the study vaccine or has any plans to receive such treatment during the study.
  • 6. If the participant cannot communicate reliably with the investigator, or, in the opinion of the investigator, is unlikely to adhere to the requirements of the study or is unlikely to complete the full course of vaccination and observation.
  • 7. Employee of the study center directly involved with the proposed study or with study investigators.

About Mahidol University

Mahidol University, a premier institution in Thailand, is dedicated to advancing healthcare through innovative research and education. As a leading sponsor of clinical trials, the university leverages its extensive expertise in medical and health sciences to facilitate rigorous scientific investigations aimed at improving patient care and public health outcomes. With a commitment to ethical practices and collaboration, Mahidol University fosters multidisciplinary approaches, engaging a diverse array of researchers and healthcare professionals to drive meaningful advancements in clinical research.

Locations

Bangkok, , Thailand

Patients applied

0 patients applied

Trial Officials

Punnee Pitisuttithum, MD

Study Chair

Vaccine Trial Centre, Faculty of Tropical Medicine, Mahidol University

Timeline

First submit

Trial launched

Trial updated

Estimated completion

Not reported

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