skip to Main Content

About Our Experts

Litjen (L.J) Tan, MS, PhD

Chief Strategy Officer

Immunization Action Coalition

L.J Tan is chief strategy officer for the Immunization Action Coalition (IAC), which he joined in January, 2013. Previously, Tan was director of medicine and public health at the American Medical Association (AMA) for 15 years.
Tan also serves as co-chair of the National Adult and Influenza Immunization Summit which is a joint project with IAC, the Centers for Disease Control and Prevention (CDC) and the National Vaccine Program Office (NVPO).
Tan recently served on the National Quality Forum’s Adult Immunizations Expert Committee and is currently a member of the Pharmacy Quality Alliance’s Adult Immunization Working Group and the European Society of Clinical Microbiology and Infectious Diseases Vaccine Study Group (EVASG). He is an editor of Journal for Disaster Medicine and Public Health Preparedness, BMC Infectious Diseases, and Medscape Infectious Diseases.
He just completed his term as an elected member of the federal National Vaccine Advisory Committee (NVAC) and continues to serve on NVAC’s HPV and Vaccine Confidence working groups. Tan has chaired NVAC’s Immunization Infrastructure Working Group and served on its Vaccine Safety Working Group.
Tan was a liaison member of CDC’s Advisory Committee for Immunization Practices (ACIP) for 12 years and currently serves on ACIP’s Adult Immunization Working Group. Previously, Tan was a member of the influenza, zoster, and evidence-based working groups of ACIP.

Deborah L. Wexler, MD

Founder and Exec. Director

Immunization Action Coalition

Dr. Deborah Wexler is founder and executive director of the Immunization Action Coalition (IAC). IAC’s mission is to increase immunization rates by providing the nation’s healthcare professionals and their patients with practical, concise, and up-to-date immunization information.
During the 1990–91 U.S. measles epidemic, Wexler, in her medical practice in Saint Paul, Minnesota, established her first standing orders protocols so that registered nurses could provide vaccination services on their own without a physician being present. Since then, she has guided IAC’s development of standing orders templates for 14 routinely recommended vaccines, along with standing orders for managing medical emergencies related to the vaccination of both children and adults. Under her leadership, IAC also publishes general guidance materials including Using Standing Orders for Administering Vaccines: What You Should Know. All IAC standing orders materials are freely available online at
Dr. Wexler’s educational background includes a bachelor of science degree in biology and an MD degree from the University of Minnesota. She completed her residency training in the Department of Family Practice and Community Health at the University of Wisconsin. Wexler serves on multiple national committees involved in vaccine policy and strategy issues. She is the recipient of the 2010 Friend of Pharmacy Immunization Leadership Award from the American Pharmacists Association and the 2011 National Childhood Immunization Champion award from Every Child By Two.

William Atkinson, MD, MPH

Assoc. Dir. Immunization Education

Immunization Action Coalition

Dr. William Atkinson is associate director for immunization education at the Immunization Action Coalition, which he joined in 2012. Atkinson attended the University of Missouri – Kansas City School of Medicine with postgraduate training in internal medicine, adult infectious diseases, and preventive medicine, receiving a master’s degree in public health from the Tulane University School of Public Health and Tropical Medicine.
For 25 years, Atkinson was a medical officer at the Centers for Disease Control and Prevention where he participated in a variety of immunization-related activities including measles surveillance and outbreak control, creation of technical and training materials for vaccine providers, and the development of national immunization policy. From 1995 through 2012, he was the writer, producer, and presenter for 125 national satellite broadcasts and webcasts on multiple vaccine-preventable disease topics. He is the recipient of numerous awards including the U.S. Public Health Service Distinguished Service medal.

Alexandra Stewart, JD

Assoc. Professor

Milken Inst. School of Public Health

Alexandra Stewart is an associate professor with the Milken Institute School of Public Health at the George Washington University in Washington, D.C. She is a graduate of Trinity College and the George Washington University Law School.
Stewart has worked with a variety of stakeholders, including the Centers for Disease Control and Prevention and the National Vaccine Program Office of the U.S. Department of Health and Human Services, conducting research and providing technical assistance to improve standards for immunization coverage and performance in children and adults.
She has examined the legal environment in the 50 states and the District of Columbia surrounding the use of standing orders for vaccine delivery. Her other research projects have focused on policy and access issues surrounding human papillomavirus vaccine, vaccination of U.S. health care personnel, the U.S. vaccine injury compensation program, vaccines and autism, immunization requirements for school and daycare entry, U.S. vaccine financing, public and private insurance coverage, and the impact of health reform initiatives on vaccine policy and practice. She also has drafted model statutes addressing state private insurance law for immunization coverage, establishment of and data sharing among state immunization information systems, and establishment of perinatal and infant hepatitis B testing and vaccination programs.

Back To Top