Infectious Disease Epidemiology Unit

Adverse perinatal outcomes associated with antiretroviral therapy for HIV: systematic review and individual participant data meta-analysis

An 'omics' approach to investigate adverse perinatal outcomes in HIV-positive women

Estimating the burden of morbidity and mortality associated with maternal HIV infection in sub-Saharan Africa 1990-2028

Global molecular epidemiology of HIV during 1990-2028

Pregnancy outcomes of women living with HIV in South Africa: prospective cohort study

Joris Hemelaar’s research focuses on the association of maternal HIV infection and antiretroviral therapy with adverse perinatal outcomes (premature birth, low birthweight), maternal outcomes (hypertension, diabetes), and longer-term outcomes of HIV-exposed uninfected children (growth, neurodevelopment, and mortality). Through the conduct and analysis of pregnancy cohorts and evidence synthesis methodologies we aim to accurately estimate the global burden of adverse pregnancy outcomes associated with maternal HIV infection and different antiretroviral therapies. This work informs international HIV treatment guidelines, such as UK, US and WHO HIV pregnancy guidelines. 

Joris Hemelaar also leads the Global HIV Molecular Epidemiology Collaboration, a large international collaboration to study the global distribution of HIV-1 genetic variants, which is crucial for HIV vaccine development. Global HIV-1 genetic diversity and evolution form a major challenge to treatment and prevention efforts and impact HIV transmission, pathogenesis, diagnosis, and treatment. He conducts large international studies to determine the global spread of HIV-1 strains, which is crucial for the design, testing and deployment of HIV vaccines.

Other interests include maternal cardiac disease, the use of artificial intelligence/machine learning for antenatal prediction of adverse perinatal outcomes, hepatitis C virus/HIV co-infection, hepatitis B virus infection in pregnancy, and preterm birth prevention.

Joris Hemelaar obtained his BSc and MSc (cum laude) in Molecular Biology and Genetics at Leiden University, The Netherlands (1997). He completed his DPhil in Molecular Immunology with Professor Sir Andrew McMichael FRS FMedSci KBE at the Weatherall Institute of Molecular Medicine and Trinity College, Oxford (2001). He conducted post-doctoral research at the Harvard Medical School, Boston, USA. He obtained his BM BCh medical degree at Magdalen College, Oxford (2007). In 2019 he completed his Specialty Training in Obstetrics and Gynaecology in Oxford, during which time he was an academic clinical fellow and clinical lecturer.

In 2021, he joined Oxford Population Health and was appointed as Honorary Consultant Obstetrician at the John Radcliffe Hospital in Oxford. He serves as a member of the British HIV Association (BHIVA) pregnancy guidelines committee. In 2024, he was awarded the title of Associate Professor at the University of Oxford and was awarded the Fellowship of the College of Obstetricians and Gynaecologists.