COVID-19 Vaccine Safety Technical (VaST) Work Group Report, June 28, 2021

The Advisory Committee on Immunization Practices (ACIP) COVID-19 Vaccine Safety Technical (VaST) Work Group has reviewed post-authorization vaccine safety data weekly or biweekly since the start of the U.S. COVID-19 vaccination program in December 2020. Updates of VaST activities and VaST assessments of safety data were presented at ACIP meetings on January 27, March 1, April 14, April 23, May 12, and June 23; ACIP meetings are open to the public. In lieu of presentations at ACIP meetings, VaST reports from March 29, May 17, and May 24 have been posted on the ACIP website.

During the VaST meeting on June 28, 2021, members reviewed data on reports of Guillain-Barré syndrome (GBS) among persons who received COVID-19 vaccination. The data are from several sources, including passive surveillance in the Vaccine Adverse Event Reporting System (VAERS) and active surveillance in the Vaccine Safety Datalink (VSD) and the Department of Veteran Affairs (VA).

• The number of preliminary cases of GBS reported to VAERS among persons after they received the Janssen (Johnson & Johnson) COVID-19 vaccine was greater than the expected number of GBS cases. The reports were not limited to a specific age group, and there was no geographic clustering. The number of observed versus expected reports was not elevated for the mRNA COVID-19 vaccines.
• Neither the VSD nor the VA data indicated that rates of GBS in the window following any of the COVID-19 vaccines differ from expected at this time; however, in VSD the rate of GBS following Janssen COVID-19 vaccine was higher than the rate following the mRNA vaccines.
• GBS has been reported after receiving AstraZeneca COVID-19 vaccine, which is used in other countries. Both Janssen and AstraZeneca COVID-19 vaccines are adenovirus vector vaccines.
• Review and adjudication of GBS case reports and diagnoses are underway in U.S. surveillance systems.
• Ongoing monitoring of GBS among persons who received the Janssen COVID-19 vaccine in the United States is needed.
• VaST will continue to review data on GBS after COVID-19 vaccination.