COVID-19 Variants

Omicron

On Tuesday, November 30, 2021, the U.S. government SARS-CoV-2 Interagency Group made the decision to classify the Omicron variant as a Variant of Concern (VOC). This decision is based on multiple factors, including the detection of Omicron cases in multiple countries, transmission and displacement of Delta in South Africa, and mutations in the virus that could indicate a reduction in the effectiveness of COVID-19 vaccines and certain monoclonal antibody treatments. No cases of this variant have been identified in the U.S. to date. CDC is following the details of this new variant.

Delta

• The Delta variant is more contagious: The Delta variant is highly contagious, more than 2x as contagious as previous variants.
• Some data suggest the Delta variant might cause more severe illness than previous variants in unvaccinated people: In two different studies from Canada and Scotland, patients infected with the Delta variant were more likely to be hospitalized than patients infected with Alpha or the original virus that causes COVID-19. Even so, the vast majority of hospitalization and death caused by COVID-19 are in unvaccinated people.
• Unvaccinated people remain the greatest concern: The greatest risk of transmission is among unvaccinated people who are much more likely to get infected, and therefore transmit the virus. Fully vaccinated people get COVID-19 (known as breakthrough infections) less often than unvaccinated people. People infected with the Delta variant, including fully vaccinated people with symptomatic breakthrough infections, can transmit the virus to others. CDC is continuing to assess data on whether fully vaccinated people with asymptomatic breakthrough infections can transmit the virus.
• Fully vaccinated people with Delta variant breakthrough infections can spread the virus to others. However, vaccinated people appear to spread the virus for a shorter time: For prior variants, lower amounts of viral genetic material were found in samples taken from fully vaccinated people who had breakthrough infections than from unvaccinated people with COVID-19. For people infected with the Delta variant, similar amounts of viral genetic material have been found among both unvaccinated and fully vaccinated people. However, like prior variants, the amount of viral genetic material may go down faster in fully vaccinated people when compared to unvaccinated people. This means fully vaccinated people will likely spread the virus for less time than unvaccinated people.
• The COVID-19 vaccines approved or authorized in the United States are highly effective at preventing severe disease and death, including against the Delta variant. But they are not 100% effective, and some fully vaccinated people will become infected (called a breakthrough infection) and experience illness. For all people, the vaccine provides the best protection against serious illness and death.
• Vaccines are playing a crucial role in limiting spread of the virus and minimizing severe disease. Although vaccines are highly effective, they are not perfect, and there will be vaccine breakthrough infections. Millions of Americans are vaccinated, and that number is growing. This means that even though the risk of breakthrough infections is low, there will be thousands of fully vaccinated people who become infected and able to infect others, especially with the surging spread of the Delta variant. Low vaccination coverage in many communities is driving the current rapid surge in cases involving the Delta variant, which also increases the chances that even more concerning variants could emerge.
• Vaccination is the best way to protect yourself, your family, and your community. High vaccination coverage will reduce spread of the virus and help prevent new variants from emerging. CDC recommends that everyone aged 12 years and older get vaccinated as soon as possible.

• The Lancaster County COVID-19 Hub
• The Pennsylvania Department of Health
• https://www.cdc.gov/coronavirus/2019-ncov/variants/delta-variant.html