CU Medicine discovers gut microbiome and metabolome markers that predict long-term COVID-19 vaccine effectiveness
Researchers from The Chinese University of Hong Kong’s (CUHK) Faculty of Medicine (CU Medicine) have identified specific gut bacteria and metabolites associated with durable immune responses to COVID-19 vaccines up to six months after vaccination. Importantly, they observed that people with low levels of Bifidobacterium adolescentis and its metabolites in their gut had shorter immune memory following an mRNA COVID vaccine. The findings are published in reputable journal Signal Transduction and Targeted Therapy.
The first human study to provide follow-up evidence that gut microbiota and metabolites modulate the durability of vaccine immunity
The efficacy of COVID-19 vaccines declines over time, necessitating recurrent booster doses. To better understand the role of the gut microbiome in modulating vaccine immunogenicity and sustaining durable immunity against SARS-CoV-2, the team conducted a longitudinal study following 161 individuals who received two doses of either an mRNA vaccine, BNT162b2 (N = 121), or an inactivated vaccine, CoronaVac (N = 40). They collected stool and blood samples at baseline, one month and six months post-vaccination to analyse neutralising antibody titers over time in relation to gut microbiome and metabolome composition.
The lead investigator and the senior author of the study, Professor Hein Min Tun, Associate Professor of the Jockey Club School of Public Health and Primary Care at CU Medicine, said, “In our previous study, we reported that Bifidobacterium adolescentis plays an important role in modulating the efficacy of COVID-19 vaccines. This new discovery also provides novel evidence that specific members of the gut microbiome, including Bifidobacterium adolescentis, and their collective metabolic outputs can influence the durability of vaccine-induced immune memory in the body.”
The other senior author, Professor Siew Ng, Croucher Professor in Medical Sciences and Associate Director of the Centre for Gut Microbiota Research at CU Medicine, added, “Understanding these microbiome-immunity interactions can guide strategies to enhance vaccine durability, which is especially important as new variants emerge while vaccine-induced antibodies wane rapidly.”
Professor Francis Chan, Dean and Director of the Centre for Gut Microbiota Research at CU Medicine, said, “This new discovery is consistent with our earlier clinical findings that a microbiota-based symbiotic formula developed by CUHK, which contains Bifidobacterium adolescentis, led to an enhanced antibody response and reduced adverse health outcomes among elderly individuals who have received COVID-19 vaccines. We believe this discovery offers a novel approach to optimising long-term vaccine efficacy and safety through modulation of the gut microbiota.”
The team hopes their results will stimulate further investigation into microbiome-targeted adjuvant therapies that strengthen vaccination programmes globally. Continued monitoring will also assess how multiple booster doses shape gut health dynamics in vaccinated populations over an extended period.