COVID-19 vaccines are safe and effective at preventing infection, hospitalization, and death. Most people who get COVID-19 are unvaccinated. However, since vaccines are not 100% effective at preventing infection, some people who are fully vaccinated will still get COVID-19. An infection of a fully vaccinated person is referred to as a “breakthrough infection.” People who get vaccine breakthrough infections can be contagious but are less likely than unvaccinated people to be hospitalized or die.
To reduce the risk of becoming infected with SARS-CoV-2 (the virus that causes COVID-19) including the Delta variant, and potentially spreading it to others, CDC recommends that fully vaccinated people:
Fully vaccinated people might choose to mask regardless of the level of community transmission, particularly if they or someone in their household is immunocompromised or at increased risk for severe disease, or if someone in their household is unvaccinated.
Get tested 5-7 days after close contact with someone with suspected or confirmed COVID-19.
Wear a mask indoors in public for 14 days after exposure or until a negative test result.
Isolate if they have tested positive for COVID-19 in the prior 10 days or are experiencing COVID-19 symptoms.
Follow any applicable federal, state, local, tribal, or territorial laws, rules, and regulations.
Viruses are constantly changing, including the virus that causes COVID-19. These changes occur over time and can lead to the emergence of variants that may have new characteristics. Vaccines continue to reduce a person's risk of contracting the virus that cause COVID-19. Vaccines are highly effective against severe illness.
People who are immunocompromised should be counseled about the potential for reduced immune responses to COVID-19 vaccines and to follow current prevention measures (including wearing a mask, staying 6 feet apart from others they don’t live with, and avoiding crowds and poorly ventilated indoor spaces) regardless of their vaccination status to protect themselves against COVID-19 until advised otherwise by their healthcare provider.
Currently approved or authorized COVID-19 vaccines protect people from getting infected and severely ill, and significantly reduce the likelihood of hospitalization and death. [i] Fully vaccinated people are less likely to become infected and, if infected, to develop symptoms of COVID-19 compared with unvaccinated people. Even when fully vaccinated people develop symptoms, they tend to be less severe symptoms than in unvaccinated people. This means they are much less likely to be hospitalized or die than people who are not vaccinated. However, people who get vaccine breakthrough infections can be contagious and spread the virus to others.
In general, people are considered fully vaccinated (Annex) against COVID-19:
2 weeks after their second dose in a 2-dose series, such as the Pfizer-BioNTech or Moderna vaccines, or
2 weeks after a single-dose vaccine, such as Johnson & Johnson’s Janssen vaccine
There is currently no post-vaccination time limit on fully vaccinated status. People are considered not fully vaccinated if they have not completed vaccination, cannot be vaccinated, or are not eligible for vaccines, including children less than 5 years of age.
Data suggest immune response to COVID-19 vaccination might be reduced in some immunocompromised people including, but not limited to, people receiving chemotherapy for cancer, people with hematologic cancers such as chronic lymphocytic leukemia, people receiving stem cells or organ transplants, people receiving hemodialysis, and people using certain medications that might blunt the immune response to vaccination (e.g., mycophenolate, rituximab, azathioprine, anti-CD20 monoclonal antibodies, Bruton tyrosine kinase inhibitors).
People who are immunocompromised should be counseled about the potential for reduced immune responses to COVID-19 vaccines and the need to continue to follow current prevention measures (including wearing a mask, staying 6 feet apart from others they don’t live with, and avoiding crowds and poorly ventilated indoor spaces) to protect themselves against COVID-19 until advised otherwise by their healthcare provider. CDC also recommends that people who are moderately to severely immunocompromised should receive an additional dose of mRNA COVID-19 vaccine after the initial 2 doses. Close contacts of immunocompromised people should also be encouraged to be vaccinated against COVID-19.
This guidance provides recommendations for fully vaccinated people, including:
How fully vaccinated people can safely resume many activities while protecting others.
How fully vaccinated people should approach domestic and international travel.
How fully vaccinated people should approach isolation, quarantine, and testing.
CDC will continue to evaluate and update public health recommendations for fully vaccinated people as more information, including on Delta and other new variants, becomes available. Further information on evidence and considerations related to these recommendations is available in the Science Brief.
Recommendations for Indoor Settings
Risk of SARS-CoV-2 infection, severe disease, and death is reduced for fully vaccinated people. However, since vaccines are not 100% effective at preventing infection, some people who are fully vaccinated will still get COVID-19 infection. Fully vaccinated people who do become infected can transmit it to others. Therefore, fully vaccinated people can further reduce their risk of becoming infected with SARS-CoV-2 and transmitting it to others by wearing a mask indoors in public in areas of substantial or high community transmission. Wearing a mask in public is most important for people who are immunocompromised due to their risk of becoming infected. Fully vaccinated people might choose to mask regardless of the level of community transmission, particularly if they or someone in their household is immunocompromised or at increased risk for severe disease, or if someone in their household is not fully vaccinated. People at increased risk for severe disease include older adults and those who have certain medical conditions, such as diabetes, overweight or obesity, and heart conditions. Fully vaccinated people should also continue to wear a mask where required by federal, state, local, tribal, or territorial laws, rules, and regulations, including local business and workplace guidance, and in correctional facilities and homeless shelters. Prevention measures are still recommended in indoor public spaces for unvaccinated people.
Current data suggest the risk of transmission of SARS-CoV-2 in outdoor settings is low. In general, fully vaccinated people do not need to wear a mask outdoors. Fully vaccinated people might choose to wear a mask in crowded outdoor settings if they or someone in their household is immunocompromised, at increased risk of severe disease, or not fully vaccinated.
Fully vaccinated travelers are less likely to get and spread SARS-CoV-2 and can now travel at low risk to themselves within the United States. International travelers need to pay close attention to the situation at their international destinations before traveling due to the spread of new variants and because the burden of COVID-19 varies globally.
Wearing a mask over your nose and mouth is required on planes, buses, trains, and other forms of public transportation traveling into, within, or out of the United States and while indoors at U.S. transportation hubs such as airports and stations. Travelers are not required to wear a mask in outdoor areas of a conveyance (like on open deck areas of a ferry or the uncovered top deck of a bus).
Domestic travel (within the United States or to a U.S. territory)
Fully vaccinated travelers do not need to get a SARS-CoV-2 viral test before or after domestic travel, unless testing is required by local, state, or territorial health authorities.
Fully vaccinated travelers do not need to self-quarantine following domestic travel.
Fully vaccinated travelers do not need to get tested before leaving the United States unless required by their destination.
Fully vaccinated air travelers coming to the United States from abroad, including U.S. citizens, are still required to have a negative SARS-CoV-2 viral test result or documentation of recovery from COVID-19 before they board a flight to the United States.
International travelers arriving in the United States are still recommended to get a SARS-CoV-2 viral test 3-5 days after travel regardless of vaccination status.
Fully vaccinated travelers do not need to self-quarantine in the United States following international travel.
For persons who live outside the United States and are considering travel to the United States, please visit International Travel for further information.
Although the risk that fully vaccinated people could become severely ill and die of COVID-19 is low, any fully vaccinated person who experiences symptoms consistent with COVID-19 should isolate themselves from others, be clinically evaluated for COVID-19, and tested for SARS-CoV-2 if indicated. The symptomatic fully vaccinated person should inform their healthcare provider of their vaccination status at the time of presentation to care.
Fully vaccinated people with no COVID-like symptoms following an exposure to someone with suspected or confirmed COVID-19
Fully vaccinated people who have come into close contact with someone with COVID-19 should be tested 5-7 days following the date of their exposure and wear a mask in public indoor settings for 14 days or until they receive a negative test result. [ii] They should isolate if they test positive. Fully vaccinated people who live in a household with someone who is immunosuppressed, at increased risk of severe disease, or unvaccinated (including children <5 years of age) could also consider masking at home for 14 days following a known exposure or until they receive a negative test result. Most fully vaccinated people with no COVID-like symptoms do not need to quarantine or be restricted from work following an exposure to someone with suspected or confirmed COVID-19, if they follow the testing and masking recommendation above. [iii]
Additionally, this guidance can be applied to clinical trial participants from:
U.S. sites who received all recommended doses of a COVID-19 vaccine that is neither approved nor authorized for use by FDA but is listed for emergency use by WHO, or who have received the full series of an “active” (not placebo) COVID-19 vaccine candidate for which vaccine efficacy has been independently confirmed (e.g., by a data and safety monitoring board).
U.S.-based AstraZeneca and Novavax COVID-19 vaccine trials. These U.S. participants in COVID-19 vaccine trials can be considered fully vaccinated 2 weeks after they complete the vaccine series, if it has been confirmed that they received “active” vaccine, and not placebo.
Interpretation of vaccine records: CDC has not recommended the use of heterologous (i.e., mix-and-match) primary series. However, the use of such strategies (including mixing of mRNA, adenoviral, and mRNA plus adenoviral products) is increasingly common in many countries outside of the United States. Therefore, for the purposes of interpretation of vaccination records, individuals can be considered fully vaccinated ≥2 weeks after receipt of the last dose if they have received any single dose of an FDA approved/authorized or WHO EUL approved single-dose series (i.e., Janssen), or any combination of two doses of an FDA approved/authorized or WHO emergency use listed COVID-19 two-dose series. The recommended interval between the first and second doses of FDA-approved/authorized and WHO-EUL listed vaccines varies by vaccine type. However, for purposes of interpretation of vaccine records, the second dose in a two dose heterologous series must have been received no earlier than 17 days (21 days with a 4 day grace period) after the first dose.
The above guidance on interpreting vaccine records does not impact CDC recommendations on primary series vaccination and should not guide clinical practice. [iv]
As of July 27, 2021
Added a recommendation for fully vaccinated people to wear a mask in public indoor settings in areas of substantial or high transmission.
As of July 16, 2021
Updated considerations for people who are immunocompromised
As of July 12, 2021
Updated Choosing Safer Activities infographic with new considerations for the example activity for outdoor gatherings with fully vaccinated and unvaccinated people.
[iv] Vaccines administered in a manner inconsistent with regulatory approval or authorization issued by the relevant authority may result in loss of liability protection, violations of the CDC COVID-19 Vaccination Program provider agreement, and lack of access to compensation programs under U.S. law.