Clinical Trial Details
— Status: Active, not recruiting
Administrative data
NCT number |
NCT05195151 |
Other study ID # |
EG9-179473 |
Secondary ID |
|
Status |
Active, not recruiting |
Phase |
N/A
|
First received |
|
Last updated |
|
Start date |
November 10, 2022 |
Est. completion date |
July 17, 2024 |
Study information
Verified date |
January 2024 |
Source |
Université de Sherbrooke |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Interventional
|
Clinical Trial 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 668 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 4th dose of vaccine. All
participants will take 1 capsule/day (probiotics or placebo) for 1 month and in the middle of
this period will receive a 4th dose of vaccine. On five occasions (inclusion, vaccination,1
month, 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 City. A subgroup of 100 participants willing to travel the
Sherbrooke Clinical Research Center for 2 times (inclusion visit and final visit) will be
invited to do a blood test. The investigators expect to reduce by 1/3 the number of seniors
who are poorly protected by the 4rd dose of vaccine 6 months after the injection thanks to
the probiotics. If successful, this approach could quickly be implemented worldwide as
probiotics have few side effects and are affordable.
Description:
The elderly are at high risk of morbidity and mortality from COVID-19. They are particularly
targeted by recent data: i) faster decline of the immune response in the elderly and ii)
increase of COVID infection 6 months after the 2nd dose of vaccine. In addition, they often
have an imbalance of the microbiota that plays a key role in the activation of the immune
system. Taking probiotics, which improve the microbiota, could increase the vaccine response
of the elderly. Indeed, it has been shown in 2 meta-analyses that probiotics improve immune
response after influenza vaccination. The investigators believe that probiotics taken at the
time of4t dose (booster dose) of vaccine could improve immune memory: i) humoral (cellular
Receptor-Binding Domain antibody) and ii) (B lymphocytes, CD4+ T and CD8+ T), in the medium
term and would then allow a greater spacing of the booster doses in the future OBJECTIVE: To
reduce by 33% the percentage of elders without RBD antibodies, 6 months after the booster
dose of vaccine, by taking 2 strains of probiotics compared to placebo. Secondary objectives:
To improve the evolution of RBD Ac by longitudinal analysis at 5 different time points
(inclusion, vaccination, 1 month, 3 months, and 6 months post-vaccination).- To compare the
evolution of neutralizing Ac and memory B, CD4+ T, and CD8+ T cells, at inclusion and 6
months post-vaccination. METHODOLOGYDesign. A randomized, intention-to-treat, blinded,
placebo-controlled trial.Investigation products are: for the intervention group, a capsule
with 2 strains of probiotics and for control group or a placebo capsule. Participants will
take one capsule per day for 30 days (15 d and 15 d after the booster dose of vaccine). Both
vaccines (Pfizer-BioNTech, Moderna) may be used depending on availability and state of
knowledge . With 1:1 allocation, via the REDCap application, using permuted blocks and
stratified according to randomization.gender, age (65-79 and 80-89 years) and vaccine type
for the booster dose. Inclusion criteria: (Pfizer-BioNTech or Moderna) for more than 6
months, volunteers for booster dose of vaccine, telephone or internet access, informed
consent, and living <75 km from CRC (only for participants for blood test visits). Exclusion
criteria: patients with allergies (soy...), COVID-19 disease, possibly affected cognitive
functions, chronically weakened immune system (AIDS...) or undergoing anti-cancer treatment.
Five finger-prick dried blood samples (DBS) are planned (inclusion, vaccination, 1, 3 and 6
months post-vaccination).The DBS will be mailed to Quebec City . A telephone or mail follow
up will be realised for each participant. A subgroup of 100 participants willing to travel
will be invited to visit us at the inclusion and final visit to do a blood test. Fecal
self-sampling (inclusion) for microbiota study will be sent to I Laforest-Lapointe's
laboratory. The levels of RBD Ac will be determined by a validated Elisa test (5 times). From
the Results Criteria.venous blood samples (inclusion and 6 months post-vaccination), will be
studied: i) the pseudotyped viral neutralization and ii) the cellular immune memory in flow
cytometry (B, T CD4+ and T CD8+ lymphocytes). With 30% undetectable RBD Ac in the placebo
group (6 months post-vaccine) and 20% in the intervention group, are required (15% attrition,
80% power, 5% two-sided test). The 668 subjects primary analysis on the dichotomous criterion
(Ac RBD) will use a GMM logistic regression model for longitudinal data with covariate
variant/time.PROJECT OUTCOMEImproving vaccination and spacing vaccine doses among the elderly
are major public health issues. If successful, probiotics could be used worldwide very
quickly. They have few side effects, are available over the counter and are affordable.