About the Vaccine Safety Datalink (VSD)

At a glance

  • The Vaccine Safety Datalink (VSD) is a collaborative project that monitors the safety of vaccines and conducts studies on adverse events (side effects or health problems that occur after vaccination).
  • VSD uses electronic health record data from its member sites to assess vaccine safety and detect adverse events in near-real time.
  • VSD findings inform U.S. vaccine safety recommendations.

Overview

The Vaccine Safety Datalink (VSD) is a collaborative project between CDC and healthcare organizations across the United States. Established in 1990, the VSD members monitor the safety of vaccines and conduct studies about rare and serious adverse events following immunization.

VSD is made up of 13 member sites:

  • 11 full participant sites provide electronic health record (EHR) data shared under a common data model with a standard data dictionary.
  • Two sites provide subject matter expertise.

VSD members across the United States

View LargerDownload
U.S. Map showing Vaccine Safety Datalink (VSD) Member Healthcare Organizations.
VSD Members

Full participant member sites

Acumen
Kaiser Permanente (KP) Northern California
Kaiser Permanente Southern California (KPSC)
Denver Health
Kaiser Permanente Colorado
Harvard Pilgrim Health Care Institute
Mid-Atlantic Permanente Medical Group
HealthPartners Institute
Kaiser Permanente Northwest
Kaiser Permanente Washington
Marshfield Clinic Research Institute

Subject matter expert only sites

Indiana University
OCHIN

Objectives

  • Conduct research on important vaccine safety questions in large populations.
  • Conduct vaccine safety studies from questions or concerns in the medical literature or from other vaccine safety systems such as the Vaccine Adverse Event Reporting System (VAERS).
  • Monitor possible rare and serious adverse events when the FDA licenses new vaccines or when the CDC Advisory Committee on Immunization Practices (ACIP) makes new vaccine recommendations. ACIP makes vaccine safety recommendations for the United States.
  • Provide timely information to ACIP.

VSD data

To accomplish these objectives, VSD reviews:

  • EHR data from member sites that are healthcare organizations, including:
    • The type of vaccine given
    • The date of vaccination
    • Other vaccinations given on the same day
  • Medical illnesses diagnosed during any visit to the healthcare facility

How the data are used

Did you know?

Researchers and public health professionals use VSD data to monitor safety when new vaccines or changes to current vaccine schedules are recommended. Thanks to research from vaccine safety monitoring systems like VSD, the public can be informed quickly of possible safety concerns.
Research articles using VSD data

Evaluating adverse events in near-real time

Researchers analyze EHR data from member sites every week to determine if the rates of specific adverse events of special interest (AESI) following a specific vaccine are higher than those in a comparison group.

  • If the rate is higher in the vaccinated group beyond a certain limit, the vaccine may be associated with an adverse event. If this occurs, CDC conducts follow-up analyses.
  • VSD publishes important safety information about many vaccines — including COVID-19, HPV, influenza and more — using RCA. 12345678910111213

Evaluating safety of vaccines in pregnancy

  • VSD has developed algorithms that do the following:
    • Identify women who are pregnant
    • Determine the start and end dates of their pregnancies
    • Link medical records for pregnant women and their infants

This helps ensure the desired study participants meet the criteria for inclusion. With the appropriate study population defined, VSD can then conduct vaccine safety studies on this population and their children.

Types of research methods

Access and use VSD data

Scientists (from outside CDC and outside the VSD network) occasionally want to analyze VSD data. Depending on the request, interested researchers may be able to access VSD data and data from VSD publications through the following:

  • Public use datasets
  • VSD data sharing program
Keep Reading Accessing and Using Data from the Vaccine Safety Datalink (VSD)

Resources

Research articles using VSD data
Print
Content Source:
National Center for Emerging and Zoonotic Infectious Diseases (NCEZID)
  1. Hanson, K. E., Goddard, K., Lewis, N., Fireman, B., Myers, T. R., Bakshi, N., Weintraub, E., Donahue, J. G., Nelson, J. C., Xu, S., Glanz, J. M., Williams, J. T. B., Alpern, J. D., & Klein, N. P. (2022). Incidence of Guillain-Barré Syndrome After COVID-19 Vaccination in the Vaccine Safety Datalink. JAMA network open, 5(4), e228879. https://doi.org/10.1001/jamanetworkopen.2022.8879
  2. Goddard, K., Lewis, N., Fireman, B., Weintraub, E., Shimabukuro, T., Zerbo, O., Boyce, T. G., Oster, M. E., Hanson, K. E., Donahue, J. G., Ross, P., Naleway, A., Nelson, J. C., Lewin, B., Glanz, J. M., Williams, J. T. B., Kharbanda, E. O., Katherine Yih, W., & Klein, N. P. (2022). Risk of myocarditis and pericarditis following BNT162b2 and mRNA-1273 COVID-19 vaccination. Vaccine, 40(35), 5153–5159. https://doi.org/10.1016/j.vaccine.2022.07.007
  3. Gee, J., Naleway, A., Shui, I., Baggs, J., Yin, R., Li, R., Kulldorff, M., Lewis, E., Fireman, B., Daley, M. F., Klein, N. P., & Weintraub, E. S. (2011). Monitoring the safety of quadrivalent human papillomavirus vaccine: findings from the Vaccine Safety Datalink. Vaccine, 29(46), 8279–8284. https://doi.org/10.1016/j.vaccine.2011.08.106
  4. Donahue, J. G., Kieke, B. A., Lewis, E. M., Weintraub, E. S., Hanson, K. E., McClure, D. L., Vickers, E. R., Gee, J., Daley, M. F., DeStefano, F., Hechter, R. C., Jackson, L. A., Klein, N. P., Naleway, A. L., Nelson, J. C., & Belongia, E. A. (2019). Near Real-Time Surveillance to Assess the Safety of the 9-Valent Human Papillomavirus Vaccine. Pediatrics, 144(6), e20191808. https://doi.org/10.1542/peds.2019-1808
  5. Sharon K. Greene, Martin Kulldorff, Edwin M. Lewis, Rong Li, Ruihua Yin, Eric S. Weintraub, Bruce H. Fireman, Tracy A. Lieu, James D. Nordin, Jason M. Glanz, Roger Baxter, Steven J. Jacobsen, Karen R. Broder, Grace M. Lee, Near Real-Time Surveillance for Influenza Vaccine Safety: Proof-of-Concept in the Vaccine Safety Datalink Project, American Journal of Epidemiology, Volume 171, Issue 2, 15 January 2010, Pages 177–188, https://doi.org/10.1093/aje/kwp345
  6. Lee, G. M., Greene, S. K., Weintraub, E. S., Baggs, J., Kulldorff, M., Fireman, B. H., Baxter, R., Jacobsen, S. J., Irving, S., Daley, M. F., Yin, R., Naleway, A., Nordin, J. D., Li, L., McCarthy, N., Vellozzi, C., Destefano, F., Lieu, T. A., & Vaccine Safety Datalink Project (2011). H1N1 and seasonal influenza vaccine safety in the vaccine safety datalink project. American journal of preventive medicine, 41(2), 121–128. https://doi.org/10.1016/j.amepre.2011.04.004
  7. Daley, M. F., Yih, W. K., Glanz, J. M., Hambidge, S. J., Narwaney, K. J., Yin, R., Li, L., Nelson, J. C., Nordin, J. D., Klein, N. P., Jacobsen, S. J., & Weintraub, E. (2014). Safety of diphtheria, tetanus, acellular pertussis and inactivated poliovirus (DtaP-IPV) vaccine. Vaccine, 32(25), 3019–3024. https://doi.org/10.1016/j.vaccine.2014.03.063.
  8. Klein, N. P., Fireman, B., Yih, W. K., Lewis, E., Kulldorff, M., Ray, P., Baxter, R., Hambidge, S., Nordin, J., Naleway, A., Belongia, E. A., Lieu, T., Baggs, J., Weintraub, E., & Vaccine Safety Datalink (2010). Measles-mumps-rubella-varicella combination vaccine and the risk of febrile seizures. Pediatrics, 126(1), e1–e8. https://doi.org/10.1542/peds.2010-0665
  9. Lieu, T. A., Kulldorff, M., Davis, R. L., Lewis, E. M., Weintraub, E., Yih, K., Yin, R., Brown, J. S., Platt, R., & Vaccine Safety Datalink Rapid Cycle Analysis Team (2007). Real-time vaccine safety surveillance for the early detection of adverse events. Medical care, 45(10 Supl 2), S89–S95. https://doi.org/10.1097/MLR.0b013e3180616c0a
  10. Nelson, J. C., Yu, O., Dominguez-Islas, C. P., Cook, A. J., Peterson, D., Greene, S. K., Yih, W. K., Daley, M. F., Jacobsen, S. J., Klein, N. P., Weintraub, E. S., Broder, K. R., & Jackson, L. A. (2013). Adapting group sequential methods to observational postlicensure vaccine safety surveillance: results of a pentavalent combination DTaP-IPV-Hib vaccine safety study. American journal of epidemiology, 177(2), 131–141. https://doi.org/10.1093/aje/kws317
  11. Weintraub, E. S., Baggs, J., Duffy, J., Vellozzi, C., Belongia, E. A., Irving, S., Klein, N. P., Glanz, J. M., Jacobsen, S. J., Naleway, A., Jackson, L. A., & DeStefano, F. (2014). Risk of intussusception after monovalent rotavirus vaccination. The New England journal of medicine, 370(6), 513–519. https://doi.org/10.1056/NEJMoa1311738
  12. Nelson, J. C., Ulloa-Pérez, E., Yu, O., Cook, A. J., Jackson, M. L., Belongia, E. A., Daley, M. F., Harpaz, R., Kharbanda, E. O., Klein, N. P., Naleway, A. L., Tseng, H. F., Weintraub, E. S., Duffy, J., Yih, W. K., & Jackson, L. A. (2023). Active Postlicensure Safety Surveillance for Recombinant Zoster Vaccine Using Electronic Health Record Data. American journal of epidemiology, 192(2), 205–216. https://doi.org/10.1093/aje/kwac170
  13. Yih, W. K., Nordin, J. D., Kulldorff, M., Lewis, E., Lieu, T. A., Shi, P., & Weintraub, E. S. (2009). An assessment of the safety of adolescent and adult tetanus-diphtheria-acellular pertussis (Tdap) vaccine, using active surveillance for adverse events in the Vaccine Safety Datalink. Vaccine, 27(32), 4257–4262. https://doi.org/10.1016/j.vaccine.2009.05.036