---
title: Gut Microbiota, the Potential Key to Modulating Humoral Immunogenicity of New Platform COVID-19 Vaccines
nct_id: NCT05150834
overall_status: UNKNOWN
sponsor: Korea University Guro Hospital
study_type: OBSERVATIONAL
primary_condition: Microbiome
countries: South Korea
canonical_url: "https://parkinsonspathways.com/agent/trials/NCT05150834.md"
clinicaltrials_gov: "https://clinicaltrials.gov/study/NCT05150834"
ct_last_update_post_date: 2021-12-09
last_seen_at: "2026-05-12T06:35:37.585Z"
source: ClinicalTrials.gov (mirrored, no enrichment)
---
# Gut Microbiota, the Potential Key to Modulating Humoral Immunogenicity of New Platform COVID-19 Vaccines

**Official Title:** Gut Microbiota, the Potential Key to Modulating Humoral Immunogenicity of New Platform COVID-19 Vaccines: Adenovirus-vectored Vaccine Versus mRNA Vaccine

**NCT ID:** [NCT05150834](https://clinicaltrials.gov/study/NCT05150834)

## Key Facts

- **Status:** UNKNOWN
- **Study Type:** OBSERVATIONAL
- **Target Enrollment:** 53
- **Lead Sponsor:** Korea University Guro Hospital
- **Conditions:** Microbiome, Vaccine, Covid-19, SARS-CoV-2, Immunogenicity
- **Start Date:** 2021-02-25
- **Completion Date:** 2023-12-31
- **CT.gov Last Update:** 2021-12-09

## Brief Summary

Vaccination is the best way to mitigate the coronavirus disease 2019 (COVID-19) pandemic, but the vaccine immunogenicity may be quite variable from person to person. There is increasing evidence suggesting that the gut microbiome is a major determinant of vaccine immunogenicity. Thus, the investigators investigated the relationship between gut microbiota and humoral immune response after COVID-19 vaccination.

## Eligibility

- **Minimum age:** 18 Years
- **Sex:** ALL
- **Healthy Volunteers:** Yes

```
Inclusion Criteria:

* People assigned to get either BNT162b2 or ChAdOx1 vaccines
* informed concents

Exclusion Criteria:

* Participants were excluded if they had a history of medication which would affect gut microbiota in the past 1 month, including antibiotics, laxatives, and motility drugs.
```

## Arms

- **ChAdOx1 vaccinated group** — From Febrary 25, 2021 to July 16, 2021, healthy healthcare workers were prospectively recruited at a tertiary hospital in Seoul, Republic of Korea, and they were assigned to get ChAdOx1 (Oxford/AstraZeneca) (n=26) vaccines. Participants were excluded if they had history of medication which would affect gut microbiota in the past 1 month, including antibiotics, laxatives, and motility drugs; previous history of positive SARS-CoV-2 test on nasopharyngeal PCR; or positive serum Spike IgG results.
- **BNT162b2 vaccinated group** — From Febrary 25, 2021 to July 16, 2021, 53 healthy healthcare workers were prospectively recruited at a tertiary hospital in Seoul, Republic of Korea, and they were assigned to get BNT162b2 (n=27) vaccines. Participants were excluded if they had history of medication which would affect gut microbiota in the past 1 month, including antibiotics, laxatives, and motility drugs; previous history of positive SARS-CoV-2 test on nasopharyngeal PCR; or positive serum Spike IgG results.

## Interventions

- **This is observational study** (OTHER) — We enrolled the healthcare workers assigned to get either BNT162b2 or ChAdOx1 by the Korean government.

## Primary Outcomes

- **Taxonomic biomarkers predicting immune responses** _(time frame: before the administration of first-dose)_ — This study aimed to analyze whether fecal microbiota composition before vaccination was associated with immmune response level

## Secondary Outcomes

- **Antibody titres after the first dose vaccination** _(time frame: 3weeks from the first-dose administration in BNT162b2 group, 8-12weeks from the first-dose administration in ChAdOx1)_
- **Antibody titres after the second dose vaccination** _(time frame: 3 weeks from the second dose administration in both BNT162b2 and ChAdOx1 groups)_

## Locations (1)

- Koera University Guro Hospital, Seoul, South Korea — _RECRUITING_

## Recent Field Changes (last 30 days)

- `status.overallStatus` — added _(2026-05-12)_
- `status.primaryCompletionDate` — added _(2026-05-12)_
- `status.completionDate` — added _(2026-05-12)_
- `status.lastUpdatePostDate` — added _(2026-05-12)_
- `design.enrollmentCount` — added _(2026-05-12)_
- `eligibility.criteria` — added _(2026-05-12)_
- `eligibility.minAge` — added _(2026-05-12)_
- `eligibility.sex` — added _(2026-05-12)_
- `outcomes.primary` — added _(2026-05-12)_
- `outcomes.secondary` — added _(2026-05-12)_
- `armsInterventions.arms` — added _(2026-05-12)_
- `armsInterventions.interventions` — added _(2026-05-12)_
- `sponsor.lead` — added _(2026-05-12)_
- `results.hasResults` — added _(2026-05-12)_
- `locations.koera university guro hospital|seoul||south korea` — added _(2026-05-12)_

---

*Canonical: https://parkinsonspathways.com/agent/trials/NCT05150834.md*  
*Source data (authoritative): https://clinicaltrials.gov/study/NCT05150834*  
*This page is a raw mirror with no AI summary, no editorial enrichment, and no Parkinson's-specific filtering.*