Modification of the COVID-19 Vaccine Response by an Intervention on the Intestinal Flora

NCT05195151 | Completed DMC

• 1 other identifier: EG9-179473
• Study Type: interventional
• Target: 592
• Locations: 1 country
• Sites: 1

Brief Summary

The elderly, who are often in poorer health, have been particularly affected by the COVID-19 pandemic. Recent study results show that while vaccines have been very effective in the short term, protection for the elderly may not be sufficient 6 months after the 2nd dose. Some countries have started to offer a 3rd dose. We are considering acting on the intestinal flora of the elderly (which is often unbalanced) in order to increase the effectiveness of the vaccination. Indeed, it has been demonstrated that probiotics (which can rebalance the intestinal flora) significantly increase the production of antibodies after vaccination against the flu virus. Our hypothesis is that taking probiotics one month before and one month after the 4th dose of COVID vaccine would result in longer lasting vaccine protection in seniors. This study will include 688 seniors, aged 65-89 years, who have not had COVID-19, who have received 3 doses of an mRNA vaccine and who will accept a another booster dose . All participants will take 1 capsule/day (probiotics or placebo) for 1 month and in the middle of this period will receive a booster dose. On 3 occasions (inclusion, 3 months and 6 months post-vaccination), they will prick their fingertip and express the drop of blood on a blotting paper. They will mail this dried blood sample in an envelope for antibody testing in Quebec Research center. A subgroup of 100 participants willing to travel at CHUS' Clinical Research Center for 2 times (inclusion visit and final visit) will be invited to do a blood test. The investigators expect to reduce the number of seniors who are poorly protected by a booster dose 6 months after the injection. If successful, this approach could quickly be implemented worldwide as probiotics have few side effects and are affordable.

Conditions

COVID-19; Vaccine Reaction; Elderly

Keywords

Probiotics; COVID-19 Vaccine; Elderly; Immunity

Outcome Measures

Primary Outcomes (1)

• Receptor-Binding Domain (RBD) antibodies, 6 months after the vaccine booster shot

  The RBD antibody level will be determined by a validated ELISA test (95% sensitivity and 100% specificity). The primary outcome measure is a dichotomous measure of RBD antibodies (detectable or undetectable). The positivity threshold was defined based on the mean optical density (colorimetric reaction on blotting paper) of negative sera +3 SD. Possibly, a quantitative variable will be available.

  inclusion, 3 and 6 months

Secondary Outcomes (1)

• Anti-N Antibodies

  inclusion, 3 and 6 months

Study Arms (2)

Probiotics

EXPERIMENTAL

taking a capsule containing the probiotics 15 d before and 15 d after booster shot.

Dietary Supplement: Taking capsule containing probiotics or placebo

Control

PLACEBO COMPARATOR

taking a capsule containing a placebo 15 d before and 15 d after booster shot.

Dietary Supplement: Taking capsule containing probiotics or placebo

Interventions

Taking capsule containing probiotics or placebo DIETARY_SUPPLEMENT

The probiotics capsule containing two strains of probiotics.

Control; Probiotics

Eligibility Criteria

• Age: 65 Years - 89 Years
• Gender Eligibility Details: Male or Female
• Healthy Volunteers: Yes
• Age Groups: Older Adult (65+)

You may qualify if:

• Men and women
• aged 65-89 years
• who have received 3 doses of a mRNA vaccine (Pfizer-BioNTech or Moderna) for more than 6 months;
• volunteered for a booster dose
• had telephone or internet access
• were able to provide informed consent
• lived \<75 km from the CRC (subgroup of 100 participants only)

You may not qualify if:

• Patients with COVID-19 disease (clinical and serological data at post);
• with possibly affected cognitive functions (score \< 12 on the Functional Activities Questionnaire (FAQ))
• with allergies (soy, lactose, yeast, maltodextrin)
• with a chronically weakened immune system (AIDS...)
• undergoing anti-cancer treatment (chemotherapy or radiotherapy)
• who do not speak French or English.

Sponsors & Collaborators

• Université de Sherbrooke: lead
• CHU de Quebec-Universite Laval: collaborator

Study Sites (1)

Centre de recherche clinique du CHUS

Sherbrooke, Quebec, J1H 5N4, Canada

Location

Related Publications (1)

• Pasquier JC, Plourde M, Ramanathan S, Chaillet N, Boivin G, Laforest-Lapointe I, Allard-Chamard H, Baron G, Beaulieu JF, Fulop T, Genereux M, Masse B, Robitaille J, Valiquette L, Bilodeau S, H Buch D, Piche A. P robiotics i nfluencing r esponse of a ntibodies over t ime in s eniors after CO VID-19 v accine (PIRATES-COV): a randomised controlled trial protocol. BMJ Open. 2025 Mar 18;15(3):e088231. doi: 10.1136/bmjopen-2024-088231.

  PMID: 40107677 DERIVED

MeSH Terms

Conditions

COVID-19

Condition Hierarchy (Ancestors)

Pneumonia, Viral; Pneumonia; Respiratory Tract Infections; Infections; Virus Diseases; Coronavirus Infections; Coronaviridae Infections; Nidovirales Infections; RNA Virus Infections; Lung Diseases; Respiratory Tract Diseases

Study Officials

• Jean-Charles Pasquier, Dr

  Université de Sherbrooke

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: January 13, 2022
• First Posted: January 18, 2022
• Study Start: November 10, 2022
• Primary Completion: July 17, 2024
• Study Completion: July 17, 2024
• Last Updated: January 15, 2025

Record last verified: 2025-01

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)