Examining antibody responses in COVID-19 patients and vaccinated individuals

Association of Phenotypic Age and Antibody Titers Among SARS-Co-V2 Infected Patients and Vaccinated Groups

Observational Chang Gung Memorial Hospital · NCT05827939

This study is trying to see how well the antibodies from COVID-19 infections and vaccinations work against the virus and if they change over time, especially in people with long-COVID symptoms.

Quick facts

Study typeObservational
Enrollment330 (estimated)
Ages20 Years and up
SexAll
SponsorChang Gung Memorial Hospital Academic / other
Locations1 site (New Taipei City)
Trial IDNCT05827939 on ClinicalTrials.gov

What this trial studies

This observational study investigates the neutralizing antibody response to SARS-CoV-2 among individuals who have been infected or vaccinated. It aims to understand how the spike protein neutralizing antibody correlates with natural infection and vaccination, as well as how mutations in viral strains affect these antibodies. The study also explores cognitive function and the decline of antibody titers over time, particularly in relation to long-COVID symptoms. A total of 97 patients from a specialized infectious pneumonia ward will be enrolled for this analysis.

Who should consider this trial

Good fit: Ideal candidates include individuals over 20 years old who have had a confirmed COVID-19 infection or have been vaccinated.

Not a fit: Patients who refuse blood draws or follow-up schedules will not benefit from this study.

Why it matters

Potential benefit: If successful, this study could enhance understanding of long-term immunity and inform vaccine efficacy against COVID-19.

How similar studies have performed: Other studies have shown promising results in understanding antibody responses to SARS-CoV-2, but this specific approach is novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

1. Age \> 20 yrs
2. Evidenced COVID-19 infeciton by PCR sequening or commercial IVD rapid test kits. (stratified by infection periods, before 2022 vs. in 2022)
3. Clealry understand the study protocol, blood drawing, organ function survey, phenoage and phenoageAccel exams and cognitive functional evaluation.
4. Agree with regular follow-up as the protocol designs

Exclusion Criteria:

1. Refuse any blood draw or follow-up schedule
2. Refuse at any time
3. The PIs judges that the patient is no longer suitable to continue the study follow-up
4. Death

Where this trial is running

New Taipei City

Study contacts

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.
Conditions COVID-19SARS-CoV-2Neutralizing antibodySpike antibodyCognitive functionlong-COVIDVaccine efficacy
Last reviewed 2026-06-13 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.