She is board certified in Pediatrics and Pediatric Infectious Diseases. She is Chairperson of the American Academy of Pediatrics Section on Infectious Diseases (SOID), a member of the AAP Committee on Infectious Diseases (Redbook Committee), and SOID liaison to the Pediatric Infectious Diseases Society (PIDS) Governing Council. She also serves as a member of the: AAP Global Immunization Advocacy Project Advisory Committee, AAP Expert Pertussis Cocooning Advisory Committee, and is a liaison to the Illinois Chapter of the AAP OB/GYN Immunizations and Pregnancy Outreach Committee. Dr. Tan is a member of the Immunization Advisory Committee for the State of Illinois Department of Public Health. She serves on the editorial boards of: Pediatrics (Official Journal of the AAP), the Journal of the Pediatric Infectious Diseases Society (Official Journal of PIDS), and the American Academy of Pediatrics PREP Self-Assessment Infectious Diseases. She is the US Representative to the International Steering Committee of the Global Pertussis Initiative; a member and consultant to the Steering Committee of the Latin America Without Pertussis Initiative (PAHEF, SLIPE); a member of the Board of Directors of the World Association of Infectious Diseases and Immunological Disorders (WAidid), and a member of the US National Pertussis Task Force (AAP and Every Child by Two). She is a member of the vaccine advisory boards of Merck, Sanofi Pasteur, GSK and Pfizer/Wyeth. Her interests include: pertussis disease and vaccine, pneumococcal disease and vaccine, CA-MRSA infections, antibiotic resistance, vaccines and vaccine preventable diseases, infectious diseases, and vaccine education for healthcare providers.