CDC COVID-19 Vaccine Guidance


COVID-19 Vaccine

Person wearing cloth face covering while getting vaccination.


As COVID-19 vaccines are authorized and then recommended for use in the United States, it will be important to understand what is known about each vaccine. CDC will provide information on when vaccination is recommended for you and what to expect when you get vaccinated, as well as information you need to be a trusted source in your community on vaccination, including the latest on vaccine safety and effectiveness. Check CDC’s COVID-19 Vaccines page frequently to stay up-to-date.


Getting vaccinated is one of many steps you can take to protect yourself and others from COVID-19. Protection from COVID-19 is critically important because for some people, the virus can cause severe illness or death. Stopping a pandemic requires using all the tools available. Vaccines work with your immune system so your body will be ready to fight the virus if you are exposed. Other steps, like covering your mouth and nose with a mask when in public, staying at least 6 feet away from others who don’t live with you, avoiding crowds and poorly ventilated spaces, and washing your hands often, or using hand sanitizer containing at least 60% alcohol if soap and water aren’t available, help reduce your chance of being exposed to the virus or spreading it to others. Together, COVID-19 vaccination and following CDC’s recommendations to protect yourself and others will offer the best protection from COVID-19.


  • Click here to learn more about the benefits of COVID-19 vaccination.
  • V-safe app 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. 
    V-safe will remind you to get your second COVID-19 vaccine dose if you need one. Your participation in CDC’s v–safe makes a difference — it helps keep COVID-19 vaccines safe. 

What To Expect

It’s important for everyone to continue using all the tools available to help stop this pandemic. Cover your mouth and nose with a mask when around others, stay at least 6 feet away from others, avoid crowds, and wash your hands often.


Click here to find out what to expect before, during and after your COVID-19 vaccine appointment


Health Considerations


Adults of any age with certain underlying medical conditions are at increased risk for severe illness from the virus that causes COVID-19. COVID-19 messenger RNA vaccines—also called mRNA vaccines—may be administered to people with underlying medical conditions provided they have not had a severe allergic reaction to any of the ingredients in the vaccine. If you have had an immediate allergic reaction to any other vaccine or injectable medicine, you should talk to your doctor about whether you should receive an mRNA COVID-19 vaccine. The most common symptoms reported are discomfort from fever or pain.  


Contact your doctor or healthcare provider:

  • If the redness or tenderness where you got the shot increases after 24 hours
  • If your side effects are worrying you or do not seem to be going away after a few days


The following information will help you make an informed decision about receiving a mRNA COVID-19 vaccine:


New COVID-19 Variants


Information about the characteristics of new COVID-19 variants is rapidly emerging. Scientists are working to learn more about how easily they might spread, whether they could cause more severe illness, and whether currently authorized vaccines will protect people against them. Currently, there is no evidence that these variants cause more severe illness or increased risk of death. Visit the CDC New COVID-19 Variants page to learn more.

Concept illustration of SARS-CoV-2 or 2019-ncov coronavirus

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 from the COVID-19 vaccine. This information helps CDC monitor the safety of COVID-19 vaccines in near real time. Depending on your answers, someone from CDC may call to check on you and get more information.

image of bottles of vaccine and needle with text COVID-19 Coronavirus

Understanding mRNA COVID-19 Vaccines

Messenger RNA vaccines—also called mRNA vaccines—are some of the first COVID-19 vaccines authorized for use in the United States. COVID-19 mRNA vaccines give instructions for cells to make a harmless piece of the so-called "spike protein”, which the virus uses to enter cells in the body. After the protein piece is made, the cell breaks down the instructions and gets rid of them. The immune system recognizes that the protein doesn’t belong there and begins making antibodies to protect against future infection. People who get vaccinated gain this protection without having to risk the serious consequences of getting sick with COVID-19. 


mRNA COVID-19 Vaccines

COVID-19 Vaccines for 12- to 15-year-olds

Adolescent girl receiving vaccination.

On May 10, 2021, the Food and Drug Administration (FDA) expanded the Emergency Use Authorization (EUA) for the Pfizer-BioNTech COVID-19 Vaccine for use in adolescents ages 12-15. On May 14, CDC’s Advisory Committee on Immunization Practices (ACIP) issued an interim recommendation in support of the EUA for the prevention of COVID-19 in adolescents ages 12-15.


Additionally, CDC recently announced that fully vaccinated people, including adolescents, no longer need to wear masks in most situations. These announcements come as many families are looking forward to summer plans, including campyouth sports, and travel. Authorization also comes as young people make up a rising proportion of new coronavirus cases in the United States.


Vaccinating adolescents is an important step toward stopping the spread of COVID-19. Yet adolescent vaccination has been met with mixed reactions, with some parents eager to vaccinate their children against COVID-19 and others expressing hesitancy. Pfizer-BioNTech’s COVID-19 Vaccine was found to be safe and effective in 12- to 15-year-olds in clinical trial. Side effects were generally consistent with those experienced by people ages 16-25. Side effects are normal signs that the body is building protection against the virus that causes COVID-19.


The COVID-19 pandemic has taken a toll on the mental health of many people, including adolescents. But as more people become eligible for vaccination, we have reason to be hopeful. In addition to preventing severe illness, COVID-19 vaccines will help adolescents safely return to doing the things they love – whether that’s school, sports, and other extracurricular activities, or socializing with friends. If you or someone you know is considering adolescent COVID-19 vaccination, talk with your pediatrician or family physician about the benefits of vaccination. CDC also has resources on credible vaccine information, and support for teens and young adults facing challenges during the COVID-19 pandemic. 

Recent updates for people who are fully vaccinated


We are regularly monitoring new data as it comes in and reviewing the science to inform our guidance and decision-making. Based on the latest science, we can say that anyone who is fully vaccinated can resume activities – indoor or outdoor – safely without a mask or physical distancing.


If you’ve been fully vaccinated:

  • You can resume activities that you did prior to the pandemic.
  • You can resume activities without wearing a mask or staying 6 feet apart, except where required by federal, state, local, tribal, or territorial laws, rules, and regulations, including local business and workplace guidance.
  • If you travel in the United States, you do not need to get tested before or after travel or self-quarantine after travel.
  • You need to pay close attention to the situation at your international destination before traveling outside the United States.
  • If you’ve been around someone who has COVID-19, you do not need to stay away from others or get tested unless you have symptoms. However, if you live or work in a correctional or detention facility or a homeless shelter and are around someone who has COVID-19, you should still get tested, even if you don’t have symptoms.

What you should keep doing: 

  • You will still need to follow guidance at your workplace and local businesses.
  • If you travel, you should still take steps to protect yourself and others. You will still be required to wear a mask on planes, buses, trains, and other forms of public transportation traveling into, within, or out of the United States, and in U.S. transportation hubs such as airports and stations. 
  • Fully vaccinated international travelers arriving in the United States are still required to get tested 3 days before travel by air into the United States (or show documentation of recovery from COVID-19 in the past 3 months) and should still get tested 3-5 days after their trip.
  • You should still watch out for symptoms of COVID-19, especially if you’ve been around someone who is sick. If you have symptoms of COVID-19, you should get tested and stay home and away from others.
  • People who have a condition or are taking medications that weaken the immune system should talk to their healthcare provider to discuss their activities. They may need to keep taking all precautions to prevent COVID-19.