Evaluating COVID-19 immunity and reinfection risk

Evaluation of COVID-19 Immune Barrier and Reinfection Risk

Sun Yat-sen University · NCT05774093

This study is testing how well COVID-19 vaccines and previous infections protect medical staff from getting reinfected with the virus over 48 weeks.

Quick facts

Study typeObservational
Enrollment300 (estimated)
SexAll
SponsorSun Yat-sen University (other)
Locations1 site (Guangzhou, Guangdong)
Trial IDNCT05774093 on ClinicalTrials.gov

What this trial studies

This observational study aims to assess the protective effect of immune barriers against secondary COVID-19 infections following vaccination or infection with the Omicron variant. It will involve 300 participants, primarily medical staff, who will be monitored over 48 weeks for COVID-19 antibody levels and symptoms of reinfection. Participants will undergo regular testing for COVID-19 antibodies and nucleic acid, with follow-up visits scheduled every few weeks to track their health status and any potential reinfections.

Who should consider this trial

Good fit: Ideal candidates include medical and administrative staff at the Third Affiliated Hospital of Sun Yat-sen University who can commit to the 48-week follow-up.

Not a fit: Patients with serious respiratory diseases or other conditions that affect immune function may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could enhance understanding of COVID-19 immunity and inform vaccination strategies to better protect against reinfection.

How similar studies have performed: While studies on COVID-19 immunity are ongoing, this specific approach to evaluating immune barriers against reinfection is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. No age limit, no gender limit;
2. Medical staff, administrative and logistics staff who work in the Third Affiliated Hospital of Sun Yat-Sen University or other participants who can cooperate with the follow-up for 48 weeks;
3. The participants need to be sure whether they have ever been infected with COVID-19, and need to be clearly remember the time when they first infected with COVID-19.

Exclusion Criteria:

1. Have the following serious respiratory diseases: such as asthma, bronchiectasis, chronic obstructive pulmonary disease, pulmonary interstitial disease, tuberculosis and other respiratory diseases that may interfere with symptom observation;
2. Those with other serious diseases or disease history that affect immune function, including but not limited to uncontrolled and unresectable malignant tumors,hematological diseases, cachexia, active bleeding, severe malnutrition, mental diseases, autoimmune diseases, HIV, etc.
3. Those who have long-term assignment plans and cannot return to the hospital regularly for follow-up.

Where this trial is running

Guangzhou, Guangdong

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: COVID-19 Infection, Immunization, Infection

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.