Millicent Lamptey Poster 2024

Millicent Naa Koshie Lamptey

Miss Millicent Naa Koshie Lamptey

Kumasi Centre for Collaborative Research in Tropical Medicine (KCCR) and Kwame Nkrumah University of Science and Technology (KNUST), Ghana

BCG-Vaccinated Children with Contact to Tuberculosis Patients Show Delayed Conversion of Mycobacterium tuberculosis-Specific IFN-γ Release


Poster Abstract

Mycobacterium (M.) bovis BCG vaccination is recommended for healthy babies after birth in several countries with a high prevalence of tuberculosis, including Ghana. Previous studies showed that BCG vaccination prevents individuals from developing severe clinical manifestations of tuberculosis, but BCG vaccination effects on the induction of IFN- γ after M. tuberculosis infection have hardly been investigated.ere, we performed IFN-γ-based T-cell assays (i.e., IFN-γ Release Assay, IGRA; T-cell activation and maturation marker assay, TAM-TB) in children who had contact with index tuberculosis patients (contacts).

These contacts were classified as either being BCG-vaccinated at birth (n = 77) or non-BCG-vaccinated (n = 17) and were followed up at three timepoints for a period of one year to determine immune conversion after M. tuberculosis exposure and potential infection.  At baseline and month 3, BCG-vaccinated contacts had significantly lower IFN-γ levels after stimulation with M. tuberculosis-specific proteins as compared to non-BCG-vaccinated contacts. This resulted in decreased proportions of positive IGRA results (BCG-vaccinated: 60% at baseline, 57% at month 3; non-BCG-vaccinated: 77% and 88%, respectively) at month 3.

However, until month 12, immune conversion in BCG-vaccinated contacts led to balanced proportions in IGRA responders and IFN-γ expression between the study groups. TAM-TB assay analyses confirmed higher proportions of IFN-γ-positive T-cells in non-BCG-vaccinated contacts. Low proportions of CD38-positive M. tuberculosis-specific T-cells were only detected in non-BCG-vaccinated contacts at baseline. These results suggest that BCG vaccination causes delayed immune conversion as well as differences in the phenotype of M. tuberculosis-specific T-cells in BCG-vaccinated contacts of tuberculosis patients. These differences are immune biomarker candidates for protection against the development of severe clinical tuberculosis manifestations.



Millicent is a research assistant at the Kumasi Centre for Collaborative Research in Tropical Medicine (KCCR) with Professor Richard O. Phillips’ Research group. She recently completed her master's degree (MPhil) at Kwame Nkrumah University of Science and Technology (KNUST) in the Department of Clinical Microbiology. Millicent holds a BSc. in Biological Sciences from KNUST. Her research experience at KCCR is mainly centered on Infection and Immunity of Tuberculosis, where she and her team are currently studying immunological mechanisms in mycobacterial infections, particularly immunopathognomonic markers for acute tuberculosis. With expertise in PCR, ELISA, PBMC isolation, and microbial culture, Millicent has contributed to 7 peer-reviewed publications, advancing our understanding of tuberculosis immunity. Her passion for gaining new knowledge and building skills for a career in infectious disease research to ultimately promote Sustainable development goal three remains at the core of her endeavors.