January 2025
Karen Sichibalo holds a master’s degree in medical parasitology from the University of Zambia and is currently undertaking a PhD in immunology at the University of Lübeck in Germany. Her passion for immunology stems from a strong interest in understanding host-pathogen interactions and leveraging this knowledge to develop host-directed therapies that would strengthen the immune system while complementing conventional treatments in fighting HIV and tuberculosis. She is particularly drawn to how the field of immunology offers endless opportunities to uncover various mechanisms underlying disease and how these insights can be used in therapeutic approaches including vaccine design.
We would love to hear more about your ongoing research. What projects are you currently working on and how do they impact the field?
My PhD research focuses on the potential benefits of high-dose vitamin D3 supplementation on innate immunity and antimycobacterial responses in adolescents living with perinatally acquired HIV-1 in Zambia. The aim is to ascertain whether vitamin D3 can be used as immunomodulatory adjuvant therapy to complement ART and reduce the incidence of microbial infections and ameliorate immune exhaustion in this cohort. We intend to ascertain this through a 96-week randomized double blinded placebo-controlled clinical trial, called VITALITY, where 400 adolescents living with HIV in Zambia received a biweekly supplementation of 20,000 IU vitamin D3 and 500 mg daily calcium carbonate (Trial ID: PACTR20200989766029). We intend to assess how vitamin D3, as a host-directed therapy, enhances neutrophil and monocyte effector functions such as phagocytic capacity and oxidative burst as well as microbial killing capacity and how it impacts chemo-/cytokine regulation in this cohort.
For resource-limited settings such as Zambia and most parts of the sub-Saharan region where HIV is a huge burden, vitamin D3 presents us with a scalable cost-effective adjuvant therapy to complement ART. Additionally, vitamin D supplementation in especially severely deficient individuals could potentially translate into reduced cases of antimicrobial resistance, in that, these individuals would be able to mount sufficient immunological responses against microbial infections. Consequently, this would ultimately reduce the use of antibiotic-dependent approaches to combat bacterial infections.
Another research project I am working on is exploring the crosstalk between gut microbiota and innate immunity in healthy adolescents and those living with HIV-1. Of note is that adolescence is a critical transitional phase in which the innate immune system undergoes maturation and becomes more robust at recognizing and killing pathogens. Significant changes in the gut microbiome composition also occur during this stage. Additionally, the innate immune system is the body’s first line of defence against pathogens and it shares a close relationship with the gut microbiota. Therefore, unravelling the crosstalk between innate immune reactivity and the gut microbiota may help us understand how gut microbiota profiles regulate the innate immune system and how this shapes disease outcomes. In this study, we hypothesize that the gut microbiota modulates innate immune responses and inflammation, potentially shaping long-term health outcomes as these adolescents transition into adulthood, with distinct differences between healthy individuals and those living with HIV.
There are many areas of science, what inspired you to choose immunology over other branches of science?
The blend of complexity that comes with immunology and its clinical impact as well as potential for transformative discoveries makes it one of the most exciting and rewarding fields to pursue. When it comes to global health, immunology is at the heart of combating pandemics and emerging infectious diseases. It plays a cardinal role in understanding the various disease mechanisms and informs the development of respective vaccines and immunotherapies. Besides, immunology is an everyday relevance because the immune system is at work every single day! Understanding immunology empowers an individual to make informed decisions about their health, from appreciating how nutrition and lifestyle impact immunity to understanding the science behind vaccines and why they are important.
What specifically stood out about Immunopaedia that made you want to be an ambassador?
Immunopaedia provides an excellent platform that promotes networking/collaborations amongst young and upcoming immunologists in Africa and across the globe. It also facilitates additional learning through the different immunology modules available on the Immunopaedia website. I appreciate the fact that these modules have been categorized into specific fields i.e. HIV/AIDS, tuberculosis, COVID etc., that particularly makes them relevant based on an individual’s field of study.
Based on your own experience, what one piece of advice would you give someone who wants to study/research immunology?
To be open-minded! Immunology is a multidisciplinary science that intersects various fields, including microbiology, genetics and bioinformatics. This integration fosters innovation and novel discoveries. It is also important to understand that negative results either from a clinical trial or in vitro experiments are still valuable. They not only explain differences in experimental conditions but most importantly help highlight differences across study populations that may ultimately warrant further study.
What has been a moment of unexpected joy or surprise in your scientific career that has stayed with you?
My greatest awe in my scientific journey is that, while many scientific disciplines play crucial roles, Immunology lies at the heart of understanding and combating diseases.
Karen Sichibalo’s recent publications:
Dzavakwa, N.V., Chisenga, M., McHugh, G., Filteau, S., Gregson, C.L., Kasonka, L., Kranzer, K., Mabuda, H.B., Mujuru, H., Redzo, N., Rowland-Jones, S., Schaible, U.E., Simms, V., Ferrand, R.A., the VITALITY team*, 2024. Vitamin D3 and calcium carbonate supplementation for adolescents with HIV to reduce musculoskeletal morbidity and immunopathology (VITALITY trial): study protocol for a randomised placebo-controlled trial. Trials 23, 78. (https://doi.org/10.1186/s13063-024-08342-z.).
Karen Sichibalo*, Katendi Changula , Chisoni Mumba , Natasha Mwila , Kennedy Chibesa, Benjamin Mubemba, King S. Nalubamba, Walter Muleya, Edgar Simulundu , Simbarashe Chitanga. (2021). Acaricide Resistance in Rhipicephalus and Amblyomma Ticks (Acari Ixodidae) in Namwala, Zambia. ( https://doi.org/10.53974/unza.jabs.5.3.668).
