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:
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- AstraZeneca’s COVID-19 vaccine
- Janssen’s COVID-19 vaccine
- Novavax’s COVID-19 vaccine
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:
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:
Because the supply of COVID-19 vaccine in the United States is currently limited, CDC is providing recommendations to federal, state, and local governments about who should be vaccinated first. CDC’s recommendations are based on those of the Advisory Committee on Immunization Practices (ACIP), an independent panel of medical and public health experts.
Each state has its own plan for deciding which groups of people will be vaccinated first. You can contact your state health department for more information on its plan for COVID-19 vaccination.
The goal is for everyone to be able easily to get a COVID-19 vaccination as soon as large quantities of vaccine are available. As the vaccine supply increases, more groups will be added to receive vaccination. Learn more about CDC recommendations for who should get vaccinated first.
After getting vaccinated, you may have some side effects, which are normal signs that your body is building protection. The most common side effects are pain and swelling in the arm where you received the shot. In addition, you may have fever, chills, tiredness, and headache. These side effects may affect your ability to do daily activities, but they should go away in a few days. Learn more about what to expect after getting a COVID-19 vaccine.
Yes. If you are pregnant, you may choose to be vaccinated when it’s available to you. There is currently no evidence that antibodies formed from COVID-19 vaccination cause any problem with pregnancy, including the development of the placenta.
People who are trying to become pregnant now or who plan to try in the future may receive the COVID-19 vaccine when it becomes available to them. There is no evidence that fertility problems are a side effect of any vaccine, including COVID-19 vaccines. There is no routine recommendation for taking a pregnancy test before you get a COVID-19 vaccine.
If you have questions about getting vaccinated, talking with a healthcare provider may might help you make an informed decision. Learn more at vaccination considerations for people who are pregnant or breastfeeding.
We don’t know how long protection lasts for those who are vaccinated. What we do know is that COVID-19 has caused very serious illness and death for a lot of people. If you get COVID-19, you also risk giving it to loved ones who may get very sick. Getting a COVID-19 vaccine is a safer choice.
Experts are working to learn more about both natural immunity and vaccine-induced immunity. CDC will keep the public informed as new evidence becomes available.
Yes. To protect yourself and others, follow these recommendations:
It’s important for everyone to continue using all the tools available to help stop this pandemic as we learn more about how COVID-19 vaccines work in real-world conditions. Experts are also looking at how many people get vaccinated and how the virus is spreading in communities. We also don’t yet know whether getting a COVID-19 vaccine will prevent you from spreading the virus that causes COVID-19 to other people, even if you don’t get sick yourself. CDC will continue to update this page as we learn more.
Together, COVID-19 vaccination and following CDC’s recommendations for how to protect yourself and others will offer the best protection from getting and spreading COVID-19. Additional information can be found at key things to know about the COVID-19 vaccine. https://www.cdc.gov/coronavirus/2019-ncov/vaccines/keythingstoknow.html.
Yes, you should be vaccinated regardless of whether you already had COVID-19. That’s because experts do not yet know how long you are protected from getting sick again after recovering from COVID-19. Even if you have already recovered from COVID-19, it is possible—although rare—that you could be infected with the virus that causes COVID-19 again. Learn more about why getting vaccinated is a safer way to build protection than getting infected.
If you were treated for COVID-19 with monoclonal antibodies or convalescent plasma, you should wait 90 days before getting a COVID-19 vaccine. Talk to your doctor if you are unsure what treatments you received or if you have more questions about getting a COVID-19 vaccine.
Experts are still learning more about how long vaccines protect against COVID-19 in real-world conditions. CDC will keep the public informed as new evidence becomes available.
The ingredients in currently available COVID-19 vaccines include mRNA, lipids, salts, sugars, and buffers. Buffers help maintain the stability of the pH solution. Vaccine ingredients can vary by manufacturer. To learn more about the ingredients in authorized COVID-19 vaccines, see
With both COVID-19 mRNA vaccines, you will need 2 shots to get the most protection. The timing between your first and second shot depends on which vaccine you received.
You should get your second shot as close to the recommended 3-week or 1-month interval as possible. However, your second dose may be given up to 6 weeks (42 days) after the first dose, if necessary. You should not get the second dose earlier than the recommended interval.
People with underlying medical conditions can receive the FDA-authorized COVID-19 vaccines as long as they have not had an immediate or severe allergic reaction to a COVID-19 vaccine or to any of the ingredients in the vaccine. Learn more about vaccination considerations for people with underlying medical conditions. Vaccination is an important consideration for adults of any age with certain underlying medical conditions because they are at increased risk for severe illness from COVID-19.
No. People with COVID-19 who have symptoms should wait to be vaccinated until they have recovered from their illness and have met the criteria for discontinuing isolation; those without symptoms should also wait until they meet the criteria before getting vaccinated. This guidance also applies to people who get COVID-19 before getting their second dose of vaccine.