Clinical immunization safety assessment (CISA) project: COVID-19 vaccine consultations and case reviews

The Clinical Immunization Safety Assessment (CISA) Project is a network of vaccine safety experts from the Centers for Disease Control and Prevention (CDC) Immunization Safety Office (ISO) and seven medical research centers. CISA responds to inquiries from U.S. healthcare providers (HCPs) and conducts vaccine safety research. This report summarizes the CISA approach to addressing provider vaccine safety inquiries during the COVID-19 pandemic and describes these consultations.

During the COVID-19 pandemic, CDC established a 24/7 on-call CISA consultation service. Inquiries were reviewed, and some of the most clinically complex were selected for comprehensive, structured CISA clinical case consultations. After confidential consultations, provider satisfaction surveys were sent, and providers were queried about patient outcomes and whether patients tolerated subsequent COVID-19 vaccinations.

From December 14, 2020, through December 31, 2022, CDC staff and CISA investigators conducted 79 comprehensive clinical case consultations (73 regarding adverse events following immunization (AEFI) after COVID-19 vaccine, and 6 pre-vaccination questions). Of the 73 AEFI consultations, 31 (42 %) included neurologic and 14 (19 %) allergic or hypersensitivity symptoms. Cardiology and hematology inquiries comprised most of the remainder. Twenty-four (30 %) provider satisfaction surveys were returned; all respondents found the service helpful. Of 38 (79 total; 48 %) returned patient follow-up surveys, 14 (37 %) reported that subsequent COVID-19 vaccines were administered and were well-tolerated in case patients.

Despite low participation rate in satisfaction and patient follow-up surveys, the CISA consultation service provided timely COVID-19 vaccine safety evaluations for HCPs through comprehensive clinical case consultations and vaccine safety guidance, a unique role in the pandemic response.