Important update: Healthcare facilities
CDC has updated select ways to operate healthcare systems effectively in response to COVID-19 vaccination. Learn more
To maximize protection from the Delta variant and prevent possibly spreading it to others, get vaccinated as soon as you can and wear a mask indoors in public if you are in an area of substantial or high transmission.
UPDATE
Given new evidence on the B.1.617.2 (Delta) variant, CDC has updated the guidance for fully vaccinated people. CDC recommends universal indoor masking for all teachers, staff, students, and visitors to K-12 schools, regardless of vaccination status. Children should return to full-time in-person learning in the fall with layered prevention strategies in place.
UPDATE
The White House announced that vaccines will be required for international travelers coming into the United States, with an effective date of November 8, 2021. For purposes of entry into the United States, vaccines accepted will include FDA approved or authorized and WHO Emergency Use Listing vaccines. More information is available here.
UPDATE
Travel requirements to enter the United States are changing, starting November 8, 2021. More information is available here.

What You Need to Know about Variants

What You Need to Know about Variants
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Discussions about the Delta Variant: Viruses constantly change through mutation, and new variants of a virus are expected to occur. Sometimes new variants emerge and disappear. Other times, new variants persist. All variants of the virus that causes COVID-19 are being tracked in the United States and globally during this pandemic.

Vaccines continue to reduce a person’s risk of contracting the virus that cause COVID-19, including this variant. Vaccines are highly effective against severe illness, but the Delta variant causes more infections and spreads faster than earlier forms of the virus that causes COVID-19.

Top Things You Need to Know

  1. Variants are expected. The best way to slow the emergence of new variants is to reduce the spread of infection by taking measures to protect yourself, including getting a COVID-19 vaccine when available.
  2. Vaccines can keep you from getting sick, being hospitalized, or dying from COVID-19.
  3. All COVID-19 tests can detect all variants, but they will not tell you which variant you have.
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Vaccines 

  • FDA approved or authorized COVID-19 vaccines protect against Delta and other known variants.
  • These vaccines protect people from getting infected and severely ill, and significantly reduce the likelihood of hospitalization and death.
  • We don’t yet know how effective the vaccines will be against new variants that may arise.
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Symptoms 

  • Most variants cause similar COVID-19 symptoms.
  • Some variants, such as the Alpha and Delta variants, may cause severe illness and death.
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Masks 

  • Wearing a mask is one effective way to reduce the spread of Delta and other variants.
  • People who are not fully vaccinated should wear a mask indoors in public at all levels of community transmission.
  • CDC recommends that people who are fully vaccinated wear a mask indoors in areas of substantial or high transmission.
  • Wearing a mask is most important if you have a weakened immune system or if, because of your age or an underlying medical condition, you are at increased risk for severe disease, or if someone in your household has a weakened immune system, is at increased risk for severe disease, or is unvaccinated. If this applies to you or your household, you might choose to wear a mask regardless of the level of transmission in your area.
  • If you have a condition or are taking medications that weaken your immune system, you may not be fully protected even if you are fully vaccinated. You should continue to take all precautions recommended for unvaccinated people unless advised otherwise by your healthcare provider.
  • People who are NOT vaccinated, should continue to take steps to protect themselves.
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Testing 

  • All tests work for all variants, but they will not tell you which variant you have.
  • As new variants emerge, scientists will continue to evaluate how well tests work.

Types of Variants

Scientists monitor all variants but may classify certain ones as Variants Being Monitored, Variants of Concern, Variants of Interest or Variants of High Consequence based on how easily they spread, how severe their symptoms are, and how they are treated.

Some variants seem to spread more easily and quickly than other variants, which may lead to more cases of COVID-19. An increase in the number of cases will put more strain on healthcare resources, lead to more hospitalizations, and potentially more deaths.

Variants of Concern in the US

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Delta - B.1.617.2

First identified: India

Spread: Much faster than other variants

Severe illness and death: May cause more severe cases than the other variants

Vaccine: Infections happen in only a small proportion of people who are fully vaccinated, even with the Delta variant. Vaccine breakthrough infections are expected, but vaccines are effective at preventing most infections. However, preliminary evidence suggests that fully vaccinated people who do become infected with the Delta variant can spread the virus to others. All approved or authorized vaccines are particularly effective against severe illness, hospitalization, and death.

Treatments: Certain monoclonal antibody treatments are less effective against this variant.