COVID-19

Things to Know about the COVID-19 Pandemic

What is COVID-19

Coronavirus disease (COVID-19) is an infectious disease caused by a newly discovered coronavirus. The COVID-19 virus spreads primarily through droplets of saliva or discharge from the nose when an infected person coughs or sneezes, so it’s important that you also practice respiratory etiquette (for example, by coughing into a flexed elbow).

What Symptoms to Watch For

The most common symptoms of COVID-19 are

  • Fever
  • Cough
  • Headaches
  • Fatigue
  • Muscle or body aches
  • Loss of taste or smell
  • Sore throat
  • Nausea
  • Diarrhea

Other symptoms are signs of serious illness. If someone has trouble breathing, chest pain or pressure, or difficulty staying awake, get medical care immediately.

Three Important Ways to Slow the Spread

  • Wear a mask to protect yourself and others and stop the spread of COVID-19.
  • Stay at least 6 feet (about 2 arm lengths) from others who don’t live with you.
  • Avoid crowds. The more people you are in contact with, the more likely you are to be exposed to COVID-19.

How to Protect Yourself When Going Out

If You are at Risk of Getting Very Sick

What to Do If You’re Sick

  • Stay home except to get medical care.
  • Isolate yourself from other members of your family to prevent spread to them and the people that they may have contact with, like grandparents.
  • Even if you don’t feel sick, you can spread COVID-19 to others.
  • Get care immediately if you are having emergency warning signs, like trouble breathing, pain or pressure in chest.

How to Get a Test for Current Infection

  • You can visit your state or local health department’s website to look for the latest local information on testing.
  • If you have symptoms of COVID-19 and want to get tested, call your healthcare provider first.
  • If you have symptoms of COVID-19 and choose to not get tested, it is important to stay home. Find out what to do if you are sick.

How to Cope with Stress

  • Care for yourself one small way each day.
  • Unwind by doing yoga, listening to music, or gardening.
  • Find new ways to connect with family and friends, get support, and share feelings.
  • Eat healthy foods and get enough rest
  • Relax by reading, listening to music, or starting a new hobby.

Effective January 26, the Centers of Disease Control and Prevention (CDC) will require all air passengers entering the United States (including U.S. citizens and Legal Permanent Residents) to present a negative COVID-19 test, taken within three calendar days of departure or proof of recovery from the virus within the last 90 days​. Airlines must confirm the negative test result or proof of recovery for all passengers two years of age and over prior to boarding. ​Airlines must deny boarding of passengers who do not provide documentation of a negative test or recovery

Please see CDC’s FAQ for answers to questions about the new requirement for proof of negative COVID-19 test or recovery from COVID-19 for all air passengers arriving in the United States.

A Closer Look at How COVID-19 mRNA Vaccines Work

COVID-19 mRNA vaccines give instructions for our cells to make a harmless piece of what is called the “spike protein.” The spike protein is found on the surface of the virus that causes COVID-19.

COVID-19 mRNA vaccines are given in the upper arm muscle. Once the instructions (mRNA) are inside the immune cells, the cells use them to make the protein piece. After the protein piece is made, the cell breaks down the instructions and gets rid of them.

Next, the cell displays the protein piece on its surface. Our immune systems recognize that the protein doesn’t belong there and begin building an immune response and making antibodies, like what happens in natural infection against COVID-19.

At the end of the process, our bodies have learned how to protect against future infection. The benefit of mRNA vaccines, like all vaccines, is those vaccinated gain this protection without ever having to risk the serious consequences of getting sick with COVID-19.

Vaccine Types

Understanding How COVID-19 Vaccines Work

This web page explains how the body fights infection and how COVID-19 vaccines protect people by producing immunity. It also describes the different types of COVID-19 vaccines that currently are available or are undergoing large-scale (Phase 3) clinical trials in the United States.​

Understanding COVID-19 mRNA Vaccines
This web page provides information about mRNA vaccines generally and about COVID-19 vaccines that use this new technology specifically.

Understanding Viral Vector COVID-19 Vaccines

This web page provides information about viral vector vaccines generally and about COVID-19 vaccines that use this new technology specifically.

Authorized and Recommended Vaccines

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 who is and is not recommended to receive each vaccine and what to expect after vaccination, as well as ingredients, safety, and effectiveness.

Currently, two vaccines are authorized and recommended to prevent COVID-19:

Vaccines in Phase 3 Clinical Trials

As of December 28, 2020, large-scale (Phase 3) clinical trials are in progress or being planned for three COVID-19 vaccines in the United States:

  • AstraZeneca’s COVID-19 vaccine
  • Janssen’s COVID-19 vaccine
  • Novavax’s COVID-19 vaccine​

To reduce introduction and spread of new variants of SARS-CoV-2, CDC issued an Order pdf icon[PDF – 9 pages] effective January 26, 2021. It requires all air passengers arriving to the US from a foreign country to get tested for COVID-19 infection no more than 3 days before their flight departs and to provide proof of the negative result or documentation of having recovered from COVID-19 to the airline before boarding the flight. For more information on this testing requirement, see the Frequently Asked Questions.

Get Tested Before Your Flight

Below is what you need to know about getting tested before your international flight.

  • Get tested with a viral test 1-3 days before you depart and again 1-3 days before you return.
  • Make sure you get your test results before you travel. If you are waiting for results, delay your travel.
  • Do not travel if your test result is positive; immediately isolate yourself, and follow public health recommendations.
  • A negative test does not mean that you were not exposed or that you will not develop COVID-19. Make sure to wear a mask, stay at least 6 feet from others, wash your hands, and watch your health for signs of illness while traveling.
  • Keep a copy of your test results with you during travel. You may be asked for them.

Plan Ahead

Check if your airline requires any health information, testing, or other documents. Some destinations require testing before travel and/or after arrival. Information about testing requirements for your destination may be available from the Office of Foreign Affairs or Ministry of Health, or the US Department of State, Bureau of Consular Affairs, Country Information webpageexternal icon.

Take steps to reduce higher-risk activities for 14 days before your trip and get tested 1-3 days before you travel. This could help reduce the chance that your travel will be interrupted or delayed by COVID-19.

All travelers with any known exposure to COVID-19 should delay travel, quarantine themselves from other people for 14 days after their last known exposure, get tested, and monitor their health.

Travelers with a known exposure to COVID-19 should delay travel, quarantine themselves from other people, get tested, and monitor their health.

Get Tested & Take Precautions After Your Flight

Get tested 3-5 days after travel AND stay home for 7 days after travel. Even if you test negative, stay home for the full 7 days. If you don’t get tested, it’s safest to stay home for 10 days. Always follow state and local recommendations or requirements related to travel.

A negative test does not mean that you were not exposed; you can still develop COVID-19. Watch for symptoms for 14 days after travel, immediately isolate yourself if you develop symptoms, and learn what to do if you are sick.

If your test is positive for COVID-19, immediately isolate yourself and follow public health recommendations. Do not travel until it is safe for you to be around others; this includes your return trip home.

You may have been exposed to COVID-19 on your travels. You may feel well and not have any symptoms, but you can be contagious without symptoms and spread the virus to others. You and your travel companions (including children) pose a risk to your family, friends, and community for 14 days after you were exposed to the virus.

Regardless of where you traveled or what you did during your trip, take these actions to protect others from getting COVID-19 for 14 days after travel:

  • Stay at least 6 feet/2 meters (about 2 arm lengths) from anyone who did not travel with you, particularly in crowded areas. It’s important to do this everywhere — both indoors and outdoors.
  • Wear a mask to keep your nose and mouth covered when you are in shared spaces outside of your home, including when using public transportation.
  • If there are people in the household who did not travel with you, wear a mask and ask everyone in the household to wear masks in shared spaces inside your home.
  • Wash your hands often or use hand sanitizer with at least 60% alcohol.
  • Watch your health: Look for symptoms of COVID-19, and take your temperature if you feel sick.

Frequently Asked Questions:

Where do I get tested?

Visit your state, territorial, tribal and localexternal icon health department’s website to look for the latest information on where to get tested.

What kind of test should I get?

You should get a viral test that can determine if you are currently infected with COVID-19. Learn more about testing for a current infection.

What else should I do before I travel to protect myself and others from COVID-19?

For 14 days before you travel, take everyday precautions like wearing masks, social distancing, and handwashing, and avoid the following activities that put you at higher risk for COVID-19:

  • Going to a large social gathering like a wedding, funeral, or party.
  • Attending a mass gathering like a sporting event, concert, or parade.
  • Being in crowds like in restaurants, bars, fitness centers, or movie theaters.
  • Taking public transportation like trains or buses or being in transportation hubs like airports.
  • Traveling on a cruise ship or river boat.

Is one test enough to prevent spread during my travel?

CDC recommends getting tested 1-3 days before your flight AND 3-5 days after your trip AND stay home for 7 days. Even if you test negative, stay home for the full 7 days. If you don’t get tested, it’s safest to stay home for 10 days. Getting tested in combination with staying home significantly reduces travelers’ risk of spreading COVID-19.

What if I recently recovered from COVID-19?

CDC does not recommend getting tested again in the three months after a positive viral test, as long as you do not have symptoms of COVID-19. If you have had a positive viral test in the past 3 months, and you have met the criteria to end isolation, travel with a copy of your positive test result and a letter from your doctor or health department that states you have been cleared for travel.