Immune pre-conditioning with oral quercetin supplement and COVID-19 mRNA vaccine responses: a randomized, double-blind, placebo-controlled trial
Abstract
BACKGROUND: Several risk factors for severe outcomes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and vaccine responsiveness are related to aging and lifestyle-related conditions, like obesity-associated diabetes. Although vaccination reduces the risk of coronavirus disease 2019 symptoms, vaccine responsiveness in older or metabolically impaired individuals remains variable.
OBJECTIVES: This study examined the effects of quercetin glycoside (QG), a bioactive compound with anti-inflammatory and antiaging properties, taken before mRNA vaccination in older or metabolically at-risk individuals, focusing primarily on immune responses and secondarily on vaccine-related reactions.
METHODS: In this randomized, double-blind, placebo-controlled, parallel-group study, participants consumed QG or a placebo daily for 4 wk before a mRNA SARS-CoV-2 booster. Each QG capsule contained 280 mg ± 5% of QG complex; 2 capsules were taken per day. Immune profiles were assessed for 3 mo post vaccination. Linear mixed-effects models evaluated changes in antibody titers and antigen-specific T-cell activation, including group, time, and their interaction as fixed effects, with age, sex, and BMI as covariates.
RESULTS: A total of 50 participants (QG = 24; placebo = 26) were analyzed. Vaccine-induced antibody responses rose markedly after the booster in both groups, with similar kinetics and magnitudes. No significant differences were found between groups in neutralizing…
How strong is the evidence?
Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 2 of 5 (High · randomized trial). Randomized trials of a reasonable size are the strongest single-study design. Reported size: 50 participants or records.
Read the paper
Related studies
- Quercetin Influences Quorum Sensing in Food Borne Bacteria: In-Vitro and In-Silico Evidence
- Phenolic-protein interactions: insight from in-silico analyses – a review
- In Silico Discovery of Candidate Drugs against Covid-19
- Neuropharmacological Effects of Quercetin: A Literature-Based Review
- In vitro and in silico anti-dengue activity of compounds obtained from Psidium guajava through bioprospecting
- Effect of Quercetin Rich Onion Extracts on Bacterial Quorum Sensing
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.