Joris Hemelaar
BM BCh (Oxon) BSc (Hons) MSc PGDip DPhil (Oxon) MRCOG
Associate Professor
- Honorary Consultant Obstetrician, Oxford University Hospital NHS Foundation Trust
- Associate Editor, Frontiers in Microbiology
- Principal Investigator
- Associate Professor
Dr Hemelaar’s research focuses on the association of maternal HIV infection and antiretroviral therapy with adverse perinatal outcomes, such as preterm birth and low birthweight. The aims are to accurately estimate the burden of adverse pregnancy outcomes associated with maternal HIV infection and antiretroviral therapies, and to elucidate the mechanisms underlying these pathologies, with a view to developing predictive, preventative and interventional strategies.
A second line of research concerns the global molecular epidemiology of HIV-1. Global HIV-1 genetic diversity and evolution form a major challenge to treatment and prevention efforts and impacts HIV transmission, pathogenesis, diagnosis, and treatment. Global HIV diversity forms a major obstacle to HIV vaccine development. He conducts large studies to determine the global spread of HIV strains, which is crucial for the design, testing and deployment of HIV vaccines.
Dr Hemelaar obtained his BSc and MSc (cum laude) in Molecular Biology and Genetics at Leiden University, The Netherlands (1997). He then completed a DPhil in Molecular Immunology with Prof Sir Andrew McMichael FRS at the Weatherall Institute of Molecular Medicine and Trinity College, Oxford (2001).
This was followed by post-doctoral research at the Harvard Medical School, Boston, USA. He obtained his BM BCh medical degree at Magdalen College, Oxford (2007) and completed his Specialty Training in Obstetrics and Gynaecology in 2019, during which time he was an Academic Clinical Fellow and Clinical Lecturer in Oxford. In 2021 he was appointed as Senior Clinical Research Fellow in the National Perinatal Epidemiology Unit (NPEU) and Honorary Consultant Obstetrician at the John Radcliffe Hospital.
Recent publications
Global and regional molecular epidemiology of HIV-1 during 1990-2024: systematic review, global survey, and analysis of prevalence.
Journal article
Khalid A. et al, (2026), The Lancet Infectious Diseases
Perinatal outcomes associated with antiretroviral therapy for pregnant women living with HIV: an umbrella review
Journal article
Boering PH. and Hemelaar J., (2026), eClinicalMedicine, 95, 103919 - 103919
Incidence, prevalence, and mortality of maternal cardiac disease: a systematic review and meta-analysis
Journal article
Tao L. et al, (2026), The Lancet Obstetrics Gynaecology & Women's Health
HIV-1 variants in population-based national surveys in sub-Saharan Africa, 2015-2022.
Journal article
Ghys PD. et al, (2026), AIDS
Neonatal mortality attributable to preterm births associated with maternal HIV infection in sub-Saharan Africa, 1990-2020.
Journal article
Nchinda N. and Hemelaar J., (2026), AIDS
