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COVID-19 Vaccination Requirement

To comply with the January 21, 2022, preliminary injunction, CDC/ATSDR will not implement or enforce Executive Order 14043’s federal employee COVID-19 vaccination requirements. Read more about federal agency COVID-19 vaccination hiring requirements.

Speakers: CDC-wide Representatives

Wences Arvelo MD, MSc

Dr. Wences Arvelo is the Associate Chief for Science, Division of Scientific Education and Professional Development

Associate Chief for ScienceDivision of Scientific Education and Professional Development (DSEPD)

Dr. Wences Arvelo works for the CDC’s Epidemiology and Workforce Branch in the Division of Scientific Education and Professional Development (DSEPD) as the Associate Chief for Science. Dr. Arvelo joined CDC as an Epidemic Intelligence Service officer in 2005. Since then, he has had an impactful career in public health with strong scientific and workforce development experience. For over eight years, Dr. Arvelo represented CDC as a scientist and technical expert in Central America and Africa, including serving as a resident advisor for CDC’s Field Epidemiology Training Program in Kenya. He joined the Epidemiology Workforce Branch in 2015, where he has served in several leadership roles supporting several training fellowships and programs within DSEPD.

Dr. Arvelo has subject matter expertise in public health workforce development and has authored over 50 publications in peer-reviewed journals. He graduated from the University of Puerto Rico Medical School, obtained a master’s in public health from the London School of Hygiene and Tropical Medicine, and completed a residency in Internal Medicine at Boston Medical Center in 2002. He ended the preventive medicine residency equivalent training through CDC’s Population Health Training In-place Program and became board certified in Preventive Medicine 2020.


Linda Vo, MPH

Linda Vo is the Evaluation Lead for the Program Performance and Evaluation Office (PPEO).

Evaluation LeadProgram Performance and Evaluation Office (PPEO)

Linda Vo is the Evaluation Lead in the CDC Program Performance and Evaluation Office (PPEO). Under CDC Chief Evaluation Officer’s leadership, she leads the agency-wide evaluation and capacity-building activities, reviews NOFOs’ logic models and evaluation sections, and oversees the CDC Evaluation Fellowship Program. She has 13 years of experience in evaluation, program, and mixed-methods studies with 11 years working in the federal setting. Ms. Vo developed and delivered tools, training, and technical assistance for implementation, evaluation, and behavioral science. She focuses on translating data into actionable insights and facilitating the use of data for program design, implementation, improvement, and sustainability. She came to CDC as an Evaluation Fellow in 2012. She most recently came to PPEO from the Division of Violence Prevention, where she led the evaluation of national violence prevention programs and worked on implementation science projects. She has also worked on injury prevention, workforce development, and emergency response programs.

Prior to CDC, Ms. Vo was a program evaluator at the Army Institute of Public Health, working on Army-enterprise community health programs, specifically injury, suicide, and behavioral risk. During her graduate studies, she coordinated a grant evaluation of an HIV/AIDS policy and advocacy foundation grant to 60+ community organizations throughout the Southeast. In addition, she conducted various mixed-methods and qualitative evaluation and research projects.  Her evaluation career began during her undergraduate studies assessing the usability and utility of a hospital website, restructuring an agricultural education training program, and the utility and impact of an afterschool mentoring program for elementary students located in low-resourced communities. She received her Master of Public Health in Behavioral Sciences and Health Education at the Emory University Rollins School of Public Health with a Mental Health Certificate and her Bachelor of Science in Community Health Planning & Administration with a Leadership Certificate from the University of Illinois at Urbana-Champaign.


Darion Smith, LT

Darion Smith is a Lieutenant in the United States Public Health Service.

LieutenantUnited States Public Health Service

Darion Smith is a Lieutenant in the United States Public Health Service Commissioned Corps (USPHS CC). He is a registered dental hygienist with over 10 years of experience in the private and public sectors. LT Smith now serves as the dedicated recruitment officer at CDC. In his current role, LT Smith provides leadership and guidance for prospective candidates interested in the USPHS CC, Active-Duty USPHS CC officers looking to serve at the CDC, and Active-Duty USPHS CC officers seeking reassignments within the CDC. His goal is to educate others about the USPHS CC to assist in accession and retention towards fulfilling the USPHS mission to protect, promote, and advance the health and safety of the nation.


Dr. Donjanea Williams

Dr. Donjanea Williams is a Health Scientist for the Program Performance and Evaluation Office.

Health ScientistProgram Performance and Evaluation Office

Dr. Donjanea Williams is currently on detail as a Health Scientist in the CDC Program Performance and Evaluation Office (PPEO). Within PPEO, she serves as coordinator of the CDC Evaluation Fellow Program, among other duties assigned under the detail. Within the CDC, Dr. Williams’ home CIO is the National Institute for Occupational Safety and Health (NIOSH) Office of Extramural Programs (OEP). In addition, she serves as the Evaluation Coordinator in the NIOSH OEP. She provides health communications support, with most of this latter role focused on communicating information related to the outcomes and impact of NIOSH-funded extramural research and training. Dr. Williams’ overall role within OEP includes representing the office on institute-level evaluation activities, providing evaluation-related technical assistance to NIOSH-funded grantees, supporting NIOSH OEP in enhancing data collection and reporting efforts, and developing annual performance reports and impact stories of extramural research and training. In addition, she is responsible for developing communication products related to extramural-funded research.

Dr. Williams has been in her current role since October 2016 but joined NIOSH in January 2014 as an Evaluation Fellow through the PPEO Program Evaluation Fellowship Program. During this time, she was assigned to NIOSH in the Office of Research Integration and Extramural Performance (now the Office of Research Integration) and served in a project management role to review of the second decade of National Occupational Research Agenda (NORA). Dr. Williams has academic training and professional experience in program evaluation; work experience in behavioral health, including in collegiate settings and workplace wellbeing and employee assistance; and served as an outreach prevention and media specialist for a college suicide prevention grant funded by the Substance Abuse and Mental Health Services Administration.


Michelle Leander Griffith, MPH

Michelle Leander Griffith is a Health Scientist with the Program Performance and Evaluation Office

Health ScientistProgram Performance and Evaluation Office

Michelle Griffith is a Health Scientist in the Monitoring and Evaluation Unit in the Program Performance and Evaluation Office within the Office of the Director at the CDC. Ms. Griffith currently serves as a Program Coordinator for the CDC Evaluation Fellowship. She supports the training and professional development of current fellows. She is also a liaison for two Centers within CDC to coordinate the development of Notice of Funding Announcements, Government Performance and Results Act reporting activities, and Data-Driven Regular Reviews.

Ms. Griffith came to CDC in 2014 as an ORISE fellow in the Center for Preparedness and worked to enhance agency-wide personal preparedness.  Later she served as A CDC Evaluation Fellow in the Center for Surveillance, Epidemiology and Laboratory Systems within the Division of Laboratory Systems, where she provided evaluation and strategic planning support to that Division.

Ms. Griffith obtained her MPH from Georgia State University, focusing on Prevention Sciences.


Cheryl Campbell

Cheryl Campbell is the Health and Human Services (HHS) Assistant Secretary for Administration.

HHS Assistant Secretary for Administration

Cheryl Campbell the HHS Assistant Secretary for Administration. Ms. Campbell previously served in an acting role since March 2021 where she has already laid the groundwork for 21st century HHS operations.  The Office of the Assistant Secretary for Administration (ASA) is responsible for the delivery of high quality, cost effective, and timely mission support services for HHS. During the critical transition period Ms. Campbell led the agencies administration through many of the nation and the world’s most challenging issues. ASA’s portfolio of responsibilities is broad; it includes the provisioning and management of human resources, technology, facilities, acquisitions, employee safety, security, labor relations, equal employment opportunity, and diversity and inclusion. Ms. Campbell is the first person to hold the position that has leadership experience at each of the HHS Op/Div. and Staff/Divs and she is the first female Assistant Secretary for Administration and first person of color to serve as the Assistant Secretary for Administration.

Ms. Campbell has an extensive background as a chief corporate executive with over 30 years of profit-driven results, annual budget planning, quarterly budget and forecast performance, operations, human capital acquisition and retention, P&L management, and strategic planning. She has supported HHS OpDivs throughout her career and is a known and trusted entity throughout HHS.  Ms. Campbell is the founder and past CEO of the EagleForce Warrior Foundation, which supports wounded, ill, and injured military service members and their extended families as they recover in the Department of Defense’s critical care facilities.

Ms. Campbell is a nationally recognized executive in Health IT; she has been named a “Healthcare IT Game Changer” by ExecutiveBiz, and FEDSCOOP recognized her as one of DC’s Top 50 most influential Women in Technology. Poets & Quants named Ms. Campbell one of the Top 50 Global Executive MBAs in the world.  She has a strong record of growing, restructuring, and optimizing organizational responsibilities in health and human services through strategic innovation, IT portfolio management, human capital identification, acquisition and growth, and operational excellence in planning and execution.

Ms. Campbell earned a Dual Global Executive MBA from Georgetown’s McDonough School of Business and ESADE Business & Law School. She also holds a BS in Information Systems Management from the University of Maryland.

Page last reviewed: April 22, 2022