Gut Microbiota Profile and Its Impact on Immunity Status in COVID-19 Vaccinated Cohorts

Active, not recruiting

• Conditions: COVID-19 Vaccination; Gut Microbiota

• Registration Number: NCT04980560
• Lead Sponsor: Chinese University of Hong Kong

Brief Summary

This study aims to examine the association between gut microbiota composition and the magnitude and duration of immune response in subjects who have received different COVID-19 vaccines in Hong Kong and to identify the differences compared to those COVID-19 recovered subjects.

Detailed Description

SARS-CoV-2, the cause of COVID-19, emerged as a new zoonotic pathogen of humans at the end of 2019 and rapidly developed into a global pandemic in March 2020. Over 106 million COVID-19 cases including 2.3 million deaths have been reported to the WHO as of February 9th 2021. Overall 80% of cases are mild/moderate or asymptomatic while 20% may develop severe or critical disease with respiratory failure requiring oxygen support and intensive care. As of 16 February 2021, 10789 cases have been confirmed in HK with 193 deaths while 10231 patients have been discharged from acute public hospitals with a mean length of stay of 15 days. Up to 16 Feb., 2021, there were 568 patients with COVID-19 have been managed at the Prince of Wales Hospital (PWH) with 12 deaths.

Studies showed that the quality of life of the patients who have recovered from COVID-19 was impaired. This situation is similar to some patients who suffered from SARS-CoV1 infection in 2003.

Natural infection by virus triggers an effective system immunity so that the host can resist or highly reduce the chance of re-infection.

In many cases, this protection can maintain a long period of time. On the other hand, vaccination, which aims to induce the similar immunity but in a controlled manner, presents only selected antigen(s) to the host through different delivery strategies. Lacking a normal virus replication cycle, vaccination can only partially mimic the infection process that makes the immunogenicity or durability of the vaccines sometimes not as effective as natural infection. This situation was also observed during the development of SARS and MERS vaccines. A number of studies focused on examining the humoral and cellular immunities from the COVID-19 patients during their acute stage or only few months after recovery. However, the long-term immunities (over a year) from the patients are not yet very clear.

The HKSAR government has procured 2 different types of COVID-19 vaccines for all the HK citizens that is one of the few regions/countries adopt this strategy. BioNTech mRNA vaccination programme will commence in early March 2021 and Sinovac inactivated whole virus vaccine will also be available soon for vaccination after formal approval recently. All these vaccines are so far only evaluated at their own designated population and countries and there is still lack of prospective study to "side-by-side" comparing the microbial biomarkers in the stool of different vaccines. Having different vaccines which will soon be available in Hong Kong, it would be of great interest to investigate and compare the microbial biomarkers in the stool of recovered COVID-19 patients versus those who have received different COVID-19 vaccines by setting up a 2-year longitudinal study.

Study Timeline

• Study Start: 2021-05-14
• Study First Submitted: 2021-07-26
• Study First Submitted QC: 2021-07-26
• Study First Posted: 2021-07-28
• Primary Completion: 2024-06-17
• Status Verified: 2024-08
• Last Update Submitted: 2024-08-23
• Last Update Posted: 2024-08-26
• Study Completion: 2025-12-31

Recruitment & Eligibility

• Status: ACTIVE_NOT_RECRUITING
• Sex: All
• Target Recruitment: 215

Inclusion Criteria

Not provided

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Exclusion Criteria

• None

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Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
To identify and compare the microbiome profile and immune response	3 months	To identify and compare the microbiome profile and immune response in subjects who have received different COVID-19 vaccines and in subjects who recovered from COVID-19 in Hong Kong

Secondary Outcome Measures

Name	Time	Method
SARS-CoV-2 specific antibody	across 24 months	Compare the levels of SARS-CoV-2 specific antibody
Compare the serum neutralization assay against pseudovirus and live virus, as well as the detection of IgM and IgG against receptor-binding domain [RBD] and S1	across 24 months	Compare the serum neutralization assay against pseudovirus and live virus, as well as the detection of IgM and IgG against receptor-binding domain \[RBD\] and S1
SARS-CoV-2 IgG antibody level	across 24 months	SARS-CoV-2 IgG antibody level in VAC cohort

Trial Locations

Locations (1)

Prince of Wales Hospital; 🇭🇰 Hong Kong, Hong Kong