COVID-19 Vaccine Safety & Development

Currently, clinical trials are evaluating investigational COVID-19 vaccines in many thousands of study participants to generate scientific data regarding safety and efficacy. If FDA determines a vaccine meets required safety and effectiveness standards, FDA may permit the vaccine to be distributed and used in the United States under an Emergency Use Authorization (EUA) or licensure. Once FDA makes its determination, the Advisory Committee on Immunization Practices (ACIP) will review available data before making vaccine recommendations to CDC. 

Once a COVID-19 vaccine is authorized or approved for use, CDC, FDA, and other federal partners will use multiple existing, robust systems and data sources to conduct ongoing safety monitoring.COVID-19 Vaccine Safety 

The U.S. vaccine safety system ensures that all vaccines are as safe as possible. Safety is the top priority while federal partners work to make COVID-19 vaccine(s) available. 

Enhancing COVID-19 Safety Monitoring

The CDC is also working to expand COVID-19 vaccine safety surveillance through new systems, additional information sources, and scaled up existing safety monitoring systems. This will give CDC and FDA the ability to evaluate vaccine safety and more sure COVID-19 vaccines are as safe as possible. 

Reporting Adverse Reactions

After a vaccine is authorized or approved for use, many vaccine safety monitoring systems watch for adverse events (possible side effects). This continued monitoring can pick up on adverse events that may not have been seen in clinical trials. If an unexpected adverse event is seen, experts quickly study it further to assess whether it is a true safety concern. Experts then decide whether changes are needed in U.S. vaccine recommendations. This monitoring is critical to help ensure that the benefits continue to outweigh the risks for people who receive vaccines.

Immediately (24/7) report severe COVID-19 vaccine reactions requiring hospitalization to the Office of Public Health (OPH) at 1-800-256-2748. For more information, view the Health Alert Networks Message 20-52: COVID-19 Vaccination Severe/Allergic Reaction Reporting.

v-safe: After Vaccination Health Checker

v-safe is a smartphone-based tool that uses text messaging and web surveys to provide personalized health check-ins after you receive a COVID-19 vaccination. Through v-safe, you can quickly tell CDC if you have any side effects after getting the COVID-19 vaccine. Depending on your answers, someone from CDC may call to check on you and get more information. V-safe will also remind you to get your second COVID-19 vaccine dose if needed.

Click here to view and print v-safe poster

Click here to view and print v-safe infosheet

How to register and use v-safe

You will need your smartphone and information about the COVID-19 vaccine you received. The information can be found on the vaccination record card you received during your vaccination; if you cannot find your card, contact your healthcare provider.


Health Check-in

Vaccine Adverse Event Reporting System (VAERS)VAERS is a national early warning system to detect possible safety problems in U.S.-licensed vaccines. VAERS is co-managed by the Centers for Disease Control and Prevention (CDC) and the U.S. Food and Drug Administration (FDA). VAERS accepts and analyzes reports of adverse events (possible side effects) after a person has received a vaccination. Anyone can report an adverse event to VAERS. Healthcare professionals are required to report certain adverse events and vaccine manufacturers are required to report all adverse events that come to their attention.

Report an Adverse Event

More Information on VAERSNational Healthcare Safety Network (NHSN)

NHSN is an acute-care and long-term care facility monitoring system that will promote reporting to VAERS.


An EUA may be issued by the FDA to allow access to critical medical products that may help during a public health emergency. An EUA is different from approval/licensure. 

The following criteria must be met for an EUA to be issued:

  • The product will be used for a serious life-threatening disease or condition.
  • Based on the totality of scientific evidence available, it is reasonable to believe the product may be effective.
  • The known and potential benefits of the product outweigh the known and potential risks of the product.
  • There is no adequate FDA-approved alternative available.

What Does an EUA Mean for Healthcare providers?

An EUA means that a COVID-19 vaccine has been authorized for use. The scope of authorized use is specified in the EUA Fact Sheet for Healthcare Providers. This is similar to a package insert for licensed vaccines.

For healthcare providers, conditions of use require:

  • Providing the recipient of the vaccine or their caregiver the EUA Fact Sheet for Recipients, which communicates vaccine benefits and risks to the recipient, via hard copy or electric copy
  • Reporting vaccine administration data to the CDC
  • Reporting vaccine administration errors and specified adverse events to VAERS

EUA Fact Sheet for Healthcare Providers

Each vaccine-specific EUA Fact Sheet for Healthcare Providers will provide the following information:

  • COVID-19 disease description
  • Dosage and administration information
  • Storage and handling instructions
  • Dose preparation and administration information 
  • Requirements for use of vaccine under EUA
  • Benefits and risks, including common adverse events (AEs)
  • Any approved available alternatives for preventing COVID-19 
  • Reporting requirements, including reporting AEs to VAERS
  • Additional resources

Can the EUA Fact Sheet for Recipients be provided electronically or is a hard copy required?

An EUA Fact Sheet for Recipients must be given to the individual receiving the vaccine or their guardian prior to the administration of the vaccine through appropriate means. This includes print, broadcast, radio, satellite, internet, other electronic means of distribution, videos/DVDs, or direct communication from public health agencies.

How do I know if the FDA has issued an EUA for a medical device?

Go to Emergency Use Authorizations for EUAs for medical devices. This page list currents EUAs issued for medical devices during the COVID-19 pandemic, as well as EUAs issued during previous public health emergencies.

Will a prescription be necessary for a vaccine under an EUA?

As of December 9, 2020, no EUAs have been issued to authorize the use of COVID-19 vaccines. If EUAs are issued for COVID-19 vaccines, it is expected that those vaccines may be administered without the requirement for an individual prescription for each vaccine recipient from an authorized healthcare provider. Under an EUA, FDA has an option to waive prescription requirements, if appropriate, depending on the authorized product specifics, authorized use, and/or emergency circumstances. In addition to an EUA, other legal authorities and/or plans may apply to vaccine administration:

  • Legal authorities for relevant emergency response agencies (e.g., state, local, tribal, and territorial health departments, healthcare professional licensing boards);
  • Standing orders issued by a state health officer or applicable medical control officials or an executive order issued by a governor to authorize certain healthcare providers (e.g., nurses, pharmacists) to administer COVID-19 vaccine;
  • State COVID-19 vaccination and emergency response plans; and
  • CDC’s COVID-19 Vaccination Program.

Does an EUA have any impact on standing orders?

Standing orders are a type of medical order authorized or allowed under state laws. They permit the delegation and delivery of healthcare services through standardized criteria and procedures. Standing orders are one mechanism to enable non-physician healthcare providers (e.g., nurses, pharmacists) to assess and vaccinate persons who meet the criteria for vaccination without requiring a direct, individual order each time. 

During emergencies, states might use other legal mechanisms to facilitate vaccine administration, such as executive orders, emergency regulations, or position statements from licensing boards. FDA does not issue standing orders. However, it is expected that EUAs for COVID-19 vaccines would allow flexibility so that states could use their own mechanisms, like standing orders, to authorize appropriate healthcare providers to administer COVID-19 vaccine(s). States should review any applicable authorizations of certain healthcare providers to administer COVID-19 vaccine under the Public Readiness and Emergency Preparedness (PREP) Act Declaration for Medical Countermeasures against COVID-19 (e.g., qualified pharmacy technicians and state-authorized pharmacy interns acting under the supervision of a qualified pharmacist). It is also expected that vaccine administration would be in accordance with the stakeholder’s official COVID-19 vaccination and emergency response plans and that vaccination providers would be enrolled in the CDC COVID-19 Vaccination Program.

Statutes and regulations regarding the use of standing orders (or similar mechanisms) vary by state. States should review their statutory and regulatory language to ensure standing orders can cover the administration of an unlicensed vaccine that has been authorized by FDA for emergency use under an EUA. Specifically, states should ensure that state law does not preclude the use of standing orders for an investigational product authorized under an EUA. States should also ensure their state laws permit the administration of COVID-19 vaccines intended to be used under EUAs (i.e., the language of the state’s laws is either broad enough to include COVID-19 vaccines or specifically lists the COVID-19 vaccines, depending on how the state’s laws are written) and that COVID-19 vaccines are administered within the scope of authorized use under the applicable EUA. 

Can a COVID-19 vaccine be administered to populations not included in the authorized use of the vaccine under its EUA?

No. Use of any vaccine in populations outside the scope of its EUA would be an unauthorized use of the vaccine. Each EUA issued by FDA will describe the scope of the vaccine’s authorized use, including populations (e.g., age groups) to which the vaccine may be administered. The scope of what is authorized under each EUA will be based on the available safety and efficacy data from populations studied in clinical trials.  

In order for liability protections under the Public Readiness and Emergency Preparedness (PREP) Act to apply, the use of the vaccine must be under an appropriate regulatory mechanism (e.g., an EUA, investigational new drug application, or approved biologics license application). Therefore, if a vaccine is authorized for use under an EUA, any use beyond the scope of what is described in the EUA would not be eligible for applicable liability protections under the PREP Act or injury compensation available under the Countermeasures Injury Compensation Program.