Dr Sarah Sheridan BA, BMed, MPH, MAppEpid, PhD, FAFPHM 
Global Health Technical Lead

Sarah Sheridan is a public health physician with expertise in applied epidemiology and strong interest in vaccine preventable disease control. Her PhD was on the impact and effectiveness of vaccination programs in Queensland using routinely collected and linked data, particularly on pertussis and varicella. At NCIRS, Sarah is the technical lead for the Global Health program area of work and also provides technical support for the development of immunisation policy and practice. Following her basic clinical training, Sarah trained in public health, with an international focus, and undertook the Applied Master of Epidemiology during which she undertook multiple projects internationally, including in Lao PDR and Papua New Guinea. Sarah has maintained a strong interest in immunisation research using linked data as well as international public health and field epidemiology, undertaking projects in Samoa.

Shiva Shrestha MHA 
Global Health Manager, Regional Vaccine Initiatives

Shiva Shrestha joined NCIRS in 2021. Shiva has over 13 years of experience managing advocacy campaigns and projects on behaviour change communication,  capacity building and technical assistance on infectious diseases such as tuberculosis, HIV/AIDS and Leprosy. Most recently he served as Head of Campaigns with Results Australia, undertaking high-level advocacy to raise funds from the Australian Government for multilateral institutions such as the Global Fund to Fight AIDS, TB and Malaria and GAVI, the Vaccine Alliance. Between 2007 and 2017, Shiva worked in India with international organisations, including the International Union Against TB and Lung Diseases, FHI 360, PATH and Lepra, where he worked closely with the Ministry of Health and Family Welfare, state health departments, non-government organisations and corporate sector partners. Shiva is passionate about ending diseases of poverty and holds a Masters in Health Administration degree from the Tata Institute of Social Science, India.

Ann Burton MBBS (Hons), MPH, FRACGP
Senior Technical Officer – Global Health

Ann Burton is a medical graduate of UNSW and completed her master’s in public health at the University of Sydney. She has 10 years of clinical and public health experience in Australia, including in remote Indigenous communities in the Northern Territory. Her international experience started with Australian Volunteer International, working in communicable disease prevention and control with the Ministry of Public Health in Northeast Thailand. This was followed by over 20 years’ experience at the country, regional and global levels in health programming and responses for conflict-affected and displaced populations in Asia, the Middle East and Sub-Saharan Africa in increasingly senior management roles. She was with the UN High Commissioner for Refugees for 17 years, including six years as the Chief of Public Health. She has a long history of collaboration with academic and other partners in a range of research projects operationally relevant to health in humanitarian contexts and has published in peer-reviewed journals on a range of areas related to public health responses. Her areas of interest include communicable disease prevention and control, outbreak responses, disease surveillance, health equity and health system strengthening.

April Murphy BNurs, MIPH, GradCertHM
Technical Officer – Global Health

April Murphy has a background in nursing, with a focus on primary health care and preventive health, and has experience in the public and private sectors, Aboriginal medical services, digital health and humanitarian responses. She has worked in international health projects in South Africa, Uganda, Lebanon, Kyrgyzstan, Democratic Republic of Congo, Central African Republic, Liberia and Papua New Guinea in areas including primary health care, childhood immunisation and nutrition, chronic disease, infectious diseases, mobile health services and mass vaccination campaigns. April completed her Master of International Public Health at the University of Sydney and remains committed to health systems strengthening and sustainable health care.

Dr Melinda (Shu) Chen MSc, PhD
Senior Research Officer – Global Health

Melinda Chen has over a decade of research and program experience in global health across academia and international organisations. She has expertise in infectious diseases control, vaccine delivery, and health and long-term care system strengthening; she has also trained in health economics and epidemiology. Before joining NCIRS, Melinda led the FHI 360 Beijing office and worked for Duke Kunshan University and Duke Global Health Institute, where she led or co-led projects on national immunisation program strengthening and tuberculosis clinical trials capacity building in China. She has consulted extensively for important global health funders and institutions, including the Bill & Melinda Gates Foundation, the World Bank and the Duke Global Health Institute. She has published extensively in medical journals including The Lancet Public Health, PLOS Medicine and BMJ Global Health. She obtained a bachelor’s degree in Medicine and English from Peking University Health Science Center (Medical School) and a master’s degree in global health from Duke University. Her PhD, completed at UNSW Sydney, focused on healthy ageing research using health economics and epidemiological methods.

Sera Ngeh BPharm, MPH, MPhil
Technical Officer – Global Health

Sera Ngeh is a pharmacist and epidemiologist with over 11 years’ experience working in international development, with a focus on, and appreciation for, the Asia-Pacific region. She is currently working as a technical advisor to the Expanded Programme on Immunization program at the Timor-Leste Ministry of Health. Sera has previously worked in Vanuatu, Solomon Islands, Papua New Guinea, Tonga, Cambodia and Switzerland on various projects that have included strengthening health systems, disaster management, infectious disease surveillance, monitoring and evaluation, coordination and training. She is passionate about local agency and ensuring that activities are suitable and sustainable for the relevant country context. More recently, Sera has worked in the immunisation program at the Western Australian Department of Health, where she focused on using linked data to improve vaccine safety surveillance, vaccine effectiveness and vaccine coverage in sub-populations.

Tanya Perrin 
Global Health Project Coordinator

Tanya Perrin has been managing childhood and adolescent immunisation programs for over 23 years. She holds a Diploma of Business, Frontline Management (Victoria University) and is commencing a Master of Public Health at the University of Adelaide. During her career she has led several immunisation projects, including ‘Vaccinating Gen Z’, an initiative that informed and educated students and parents in the Victorian School Based Vaccination Program. She then led a project to help increase vaccination coverage of Aboriginal and Torres Strait Islander people and became an author of a children’s storybook, A Yarn About Germs, which has been distributed nationally and translated into two Indigenous languages. Tanya has also been the supervisor for the Program for Refugee Immunisation Monitoring and Education, a Victorian Department of Health initiative that has been running since 2017. Most recently, she headed a project to increase COVID-19 vaccination coverage in multicultural communities. Tanya is passionate about immunisation and strives for evidence-based best practice.

Tonia Marquardt MBBS, FAFPHM, FRACGP, FACRRM, MPH
Staff Specialist – Global Health

Tonia Marquardt is a public health physician with an interest in global public health, particularly in low- and middle-income countries. She has over 20 years of experience working with organisations including Médecins Sans Frontières and the Royal Flying Doctor Service both internationally and in Far North Queensland. Along with her public health specialty, Tanya has fellowships in general practice and rural and remote medicine.

Ye Jin (Zoe) Joo BMedSci, MPH 
Senior Research Officer – Global Health

Zoe Joo holds qualifications and experience in public health and epidemiology. She first gained an interest in immunisation and epidemiology as an intern for the World Health Organization (Fiji), where there was a meningococcal C outbreak. From 2019, she supported the Australian Technical Advisory Group on Immunisation on influenza and COVID-19 vaccines through her work at NCIRS. Zoe then was a Master of Philosophy in Applied Epidemiology scholar at NCIRS from 2021, conducting further analysis on COVID-19 and invasive meningococcal disease. She is interested in bridging the gap between immunisation research and policy. Zoe is looking forward to providing technical assistance and supporting capacity building for NCIRS’ global collaborations.

Dr Ketaki Sharma MBBS, MPH, FRACP
Staff Specialist/Clinical Lecturer – Research to Inform Policy
Patrick ('Paddy') Cashman BHSc, MPH&TM, GCertAppMgt 
Global Health Technical Officer 

Paddy Cashman has worked in infectious diseases, ED, ICU, public health, remote health and, most recently, public health immunisation, at the Hunter New England Public Health Unit. A qualified registered nurse, he is a current doctoral candidate at the University of Newcastle. Paddy manages the Vaxtracker active adverse event following immunisation surveillance system and is a member of AusVaxSafety, COSSI and the Adverse Events Following Immunisation Clinical Assessment Network (AEFI-CAN). His interests include Aboriginal and Torres Strait Islander health, health worker education, the social science of immunisation and vaccine pharmacovigilance. He received the Public Health Association of Australia 2021 National Immunisation Achievement Award.

Karina Stamef 
Global Health Program Officer

Karina Stamef has extensive experience coordinating project and program teams across multiple sectors, including ICT, telecommunications and the airline industry. Most recently, Karina worked as Community Engagement Manager at Sutherland Hospital, where she managed over 150 volunteers, the Consumer Advisory Group, fundraising and community engagement activities. Karina also supported the hospital’s Infection Prevention and Control Team in their response to Covid-19. Karina holds a Bachelor of Arts (Development Studies) from Macquarie University. She also worked in Tonga through the Good Return's Field Support Officer Program with a local microfinance organisation (South Pacific Business Development) that assists women with microenterprise development services.

Heidi Williams
Senior Administration Officer, Global Health 

Heidi Williams joined NCIRS in June 2019. Previously, Heidi worked at Kids Research in various roles within the operations team for over 12 years. Heidi has experience in various areas of research, including operations support, administration and research animal care.  

Last updated January 2024