Research areas comprise cost-effectiveness methods, for example, in vaccinology, transfusion science, prevention of (complications) of chronic diseases, orphan drugs and personalized medicine, inclusive gene therapies. He serves (served) on various committees advising the Dutch government on reimbursement of drugs and vaccines (CVZ/ZiNL and Health Council). Also, he is advisor to various health-economics consultancy companies and pharmaceutical companies worldwide, Ministries of Health in neighbouring countries, member of editorial boards of various scientific journals (for example, Value in Health, Frontiers in Pharmacology, Vaccines and PLoS One), on advisory boards for pharmaceutical companies, expert consultant for WHO and member of WHO’s SAGE-committees. He is a member of UK’s Joint Committee of Vaccination & Immunization and advisor to the All Wales Medicines Strategy Group (Grwp Strategaeth Meddyginiaethau Gymru Gyfam). He is specialized in the role of pharmacoeconomics/health economics in the reimbursement process. He has approximately 500 MEDLINE-publications, an H-factor of 60 and extensive teaching/lecturing experience (Groningen, Amsterdam, Utrecht, Heidelberg, Bielefeld, Ankara, Sofia, various universities in Indonesia, JoBurg, Moscow and Hanoi). So far, he attracted 10 EU-projects, 10 WHO-projects, various national projects from the National Institute of Public Health and the MoH, projects from NGOs and multiple projects from pharma, aggregating to over 15 million EUR in the last decade. His research often features in newspapers and Dutch television. He is involved in 5 spin-off consultancy companies from the University in various roles.