Important update: Healthcare facilities

CDC has updated select ways to operate healthcare systems effectively in response to COVID-19 vaccination. Learn more

Find the latest information:
Recommendations for Fully Vaccinated People
COVID-19 Homepage

UPDATE

Given new evidence on the B.1.617.2 (Delta) variant, CDC has updated the guidance for fully vaccinated people. CDC recommends universal indoor masking for all teachers, staff, students, and visitors to K-12 schools, regardless of vaccination status. Children should return to full-time in-person learning in the fall with layered prevention strategies in place.

UPDATE

The White House announced that vaccines will be required for international travelers coming into the United States, with an effective date of November 8, 2021. For purposes of entry into the United States, vaccines accepted will include FDA approved or authorized and WHO Emergency Use Listing vaccines. More information is available here.

UPDATE

Travel requirements to enter the United States are changing, starting November 8, 2021. More information is available here.

COVID-19 Vaccine Safety Reporting Systems

Updated Dec. 1, 2022

Español | Other Languages

What You Need to Know

Hundreds of millions of people in the United States have safely received COVID-19 vaccinations.
COVID-19 vaccines have undergone the most intensive safety monitoring in U.S. history.
Vaccine safety monitoring uses established systems like the:
- Vaccine Adverse Event Reporting System (VAERS)
- Vaccine Safety Datalink (VSD)
- Clinical Immunization Safety Assessment (CISA) Project
CDC’s v-safe After Vaccination Health Checker is a new smartphone-based system that was developed for COVID-19 vaccine safety monitoring. Vaccine recipients can enroll and report how they or their dependents feel after they receive a vaccine.
CDC provides timely updates on selected adverse events reported to VAERS after COVID-19 vaccination.

Vaccine Safety Monitoring Process

After a vaccine is authorized or approved for use, vaccine safety systems monitor adverse events (rare health conditions) and watch for potential safety problems.

This continued monitoring can identify adverse events that may not have been seen in clinical trials. If an unexpected adverse event is seen, experts quickly study it to assess whether it presents a safety concern.
Experts then decide whether changes are needed in U.S. vaccine recommendations or clinical guidance.
Vaccine safety monitoring is critical to help ensure that the benefits of vaccination continue to outweigh the risks for people who receive vaccines.

The U.S. Food and Drug Administration’s (FDA) COVID-19 Vaccines website includes important recommendations for ongoing safety evaluations after any COVID-19 vaccine is made available under Emergency Use Authorization (EUA) or receives full FDA approval.

In addition to scaling up existing safety monitoring systems, CDC expanded its vaccine safety surveillance through a new smartphone-based system called v-safe.

New safety monitoring system

The following system and information sources were developed during the COVID-19 pandemic. They add an additional layer of safety monitoring, giving CDC and FDA the ability to evaluate COVID-19 vaccine safety in real time and make sure COVID-19 vaccines are as safe as possible.

CDC’s v-safe After Vaccination Health Checker — A smartphone-based platform for people and their dependents who receive COVID-19 vaccines.

V-safe uses text messaging and web surveys from CDC to check in with vaccine recipients following COVID-19 vaccination.
V-safe also provides second vaccine dose reminders, if needed, and telephone follow-ups to anyone who reports medically attended adverse events.
Participants can enroll in v-safe after any dose of vaccine, and parents and guardians can enroll on behalf of their dependents.

V-safe COVID-19 Vaccine Pregnancy Registry — The v-safe COVID-19 Vaccine Pregnancy Registry is a registry to collect additional health information from v-safe participants who report being pregnant at the time of vaccination or a positive pregnancy test after vaccination. This information helps CDC monitor the safety of COVID-19 vaccines in people who are pregnant.

Existing safety monitoring systems

CDC, FDA, and other federal partners use the following systems and data sources to conduct comprehensive vaccine safety monitoring:

CDC and FDA’s Vaccine Adverse Event Reporting System (VAERS)— A national system that accepts reports from healthcare professionals, vaccine manufacturers, and the public of adverse events that happen after vaccination. Reports of adverse events that are unexpected, appear to happen more often than expected, or have unusual patterns are further assessed.
- The majority of reports to VAERS after COVID-19 vaccination have been non-serious adverse events.
- There are two ways to report an adverse event to VAERS: report online or report using a writable pdf form. If you need further assistance reporting to VAERS, please email info@VAERS.org or call 1-800-822-7967.
- For healthcare providers: Under Emergency Use Authorization, FDA requires healthcare professionals to report to VAERS certain adverse events that occur after COVID-19 vaccination. CDC also encourages reporting of any medically important adverse event even if it isn’t clear that the vaccine caused the health problem.
- Learn more: How VAERS helps to monitor vaccine safety

Watch videos:

The Vaccine Safety Datalink (VSD) — A network of nine integrated healthcare organizations across the United States that conducts active surveillance and research using electronic health records; the system is also used to help determine whether possible side effects identified using VAERS are related to vaccination.
CDC’s Clinical Immunization Safety Assessment (CISA) Project — A collaboration between CDC and seven medical research centers to provide expert consultation on individual cases, assist with vaccine safety surveillance, and conduct clinical research studies about vaccine safety.
The Centers for Medicare and Medicaid Services (CMS) — A claims-based system for active surveillance and research.
FDA’s Biologics Effectiveness and Safety (BEST) System — A system of electronic health records, administrative, and claims-based data for active surveillance and research.

CDC and FDA currently have four existing safety monitoring systems in place to capture information about vaccination during pregnancy and closely monitors that information reported to each system.

CDC and FDA’s Vaccine Adverse Event Reporting System (VAERS) — VAERS is a national system to which healthcare professionals, vaccine manufacturers, and the public can report possible side effects or health problems that happen after vaccination. Scientists investigate reports of events that are unexpected, appear to happen more often than expected, or have unusual patterns. The VAERS reporting form has a question to identify pregnant people (question 8). CDC clinicians review all pregnancy reports related to COVID-19 vaccinations.
The Vaccine Safety Datalink (VSD) — VSD is a network of nine integrated healthcare organizations across the United States that monitor and evaluate the safety of vaccines. The system is also used to help determine whether possible side effects identified using VAERS are related to vaccination. Through VSD, CDC studies:
- Weekly counts and rates of COVID-19 vaccination in pregnant people
- Miscarriage and stillbirth that occurs among people who received COVID-19 vaccine during pregnancy
- Adverse outcomes in pregnancy following COVID-19 vaccination, including:
  - Pregnancy complications
  - Birth outcomes
  - Infant outcomes for the first year of life (includes infant death, birth defects, and developmental disorders)
CDC’s Clinical Immunization Safety Assessment (CISA) Project — The CISA Project is a collaboration between CDC and seven medical research centers to provide expert consultation on individual cases of adverse events after vaccination and conduct clinical research studies about vaccine safety. CISA will implement a clinical research study on COVID-19 vaccine safety among pregnant people at three sites. The study will:
- Enroll pregnant people who plan to receive COVID-19 vaccination; COVID-19 vaccines will be given as part of the study
- Collect baseline maternal health information, including if they previously had COVID-19
- Study people during pregnancy and for three months after delivery
- Study infants during their first three months of life
CDC’s Birth Defects Study to Evaluate Pregnancy Exposures (BD-STEPS) — BD-STEPS is an ongoing study that collects information, including COVID-19 vaccination information, from people who have recently been pregnant to understand the potential causes of birth defects and how to prevent them.

Department of Defense’s (DOD’s) VAERS data— Spontaneous adverse event reporting to VAERS for the DOD population.
DOD’s Vaccine Adverse Event Clinical System (VAECS) — A system for case tracking and evaluation of adverse events following immunization in DOD and DOD-affiliated populations.
DOD’s Electronic Health Record and Defense Medical Surveillance System — Large, linked electronic health records (AHLTA/MHS GENESIS) and administrative data systems for near real-time safety monitoring and research.

Department of Veterans Affairs (VA) Adverse Drug Event Reporting System (VA ADERS) — A national reporting system for adverse events following receipt of drugs and immunizations.
VA Electronic Health Record — A system of electronic health record and administrative data for active surveillance and research.

Indian Health Service (IHS) vaccine safety monitoring systems:

Passive surveillance

Vaccine Adverse Event Reporting System (VAERS)
- VAERS functionality permits analysis of adverse events in IHS system of care
IHS Safety Tracking & Response System
- Federal and participating tribal sites
- Worker-related adverse events and vaccine administration errors

Active surveillance

IHS Sentinel Survey
- Biweekly survey of adverse events, including vaccine administration errors
- 58 federal and tribal sites representing IHS Areas
- Supports reporting to VAERS

Resources

More Information

For Healthcare and Public Health