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Variants

Omicron Variant Identified

12.3.2021: Countries around the world, including the United States, are on heightened alert and stepping up precautions against COVID-19 in response to the discovery of Omicron, a new COVID-19 variant that the World Health Organization immediately classified as a “variant of concern.”

Initially reported by doctors in South Africa in late November 2021, the variant, technically identified as B.1.1.529, has already been detected in numerous other counties and was first detected in a patient in the United States on Dec. 1.

Why all the concern?

The Omicron variant has health officials concerned because it is defined by 47 mutations of the original SARS-C0V-2 virus that causes COVID-19. Some of these mutations could elude antibodies created by current COVID vaccines to fight the virus. But scientists stress that they do not have enough data currently to know what impact Omicron will have on vaccines. “We currently do not have any data to know for sure the impact that Omicron will have on immune evasion, both from vaccines and previous infection,” said Yale School of Public Health Professor Nathan Grubaugh, Ph.D., who tracks emerging SARS-CoV-2 variants using genomic surveillance. Grubaugh and other leading scientists expect to have a better sense of Omicron’s threat potential by late December.

The biggest question of concern is whether Omicron will overtake the existing COVID-19 Delta variant, which continues to be the dominant variant causing serious illness – primarily among individuals who are unvaccinated - around the world.

What precautions can people take now against Omicron?

“First and foremost, we should be concerned about what is happening right now with Delta,” Grubaugh said. “Cases in Connecticut and across the U.S. are on the rise, which was expected with the winter months and the holiday season. To stop Delta, and to not give Omicron a chance to spread, we need to focus on reducing local transmission through mask wearing in public, routine testing, isolating when exposed or positive and keeping up with the recommended vaccinations.”

What we don’t know yet about Omicron

Scientists around the world are analyzing all available data regarding Omicron as it becomes available in real time. According to the U.S. Centers for Disease Control and Prevention, here are the key things we don’t yet know:

  1. How efficiently the Omicron variant can spread from person to person. The replacement of Delta by Omicron as the predominant variant in South Africa has raised concerns that the Omicron variant may be more transmissible than Delta. But due to the low number of cases in South Africa when Omicron emerged, it is unclear if this variant is more transmissible than the Delta variant.
  2. Disease severity. Currently, it is unclear if infection with the Omicron variant is associated with more severe disease. Due to the small number of cases attributed to the Omicron variant, assessment of disease severity is difficult. Preliminary information from South Africa indicates that there are no unusual symptoms associated with Omicron variant infection, and as with other variants, some patients are asymptomatic.
  3. Impact on Vaccine-Induced Immunity or Immunity from Previous Infection: Currently, there are no data available to assess the ability of sera from vaccinated persons or those with previous SARS-CoV-2 infection to neutralize the Omicron variant. The spike protein is the primary target of vaccine-induced immunity. The Omicron variant contains more changes in the spike protein than have been observed in other variants. Based on the number of substitutions, the location of these substitutions, and data from other variants with similar spike protein substitutions, significant reductions in neutralizing activity of sera from vaccinated or previously infected individuals, which may indicate reduced protection from infection, are anticipated.

I keep hearing about COVID-19 variants posing a new threat. What are these variants, and will a vaccine help me avoid them?

Viruses constantly mutate as they are transmitted between people. The virus that causes COVID-19 is no exception. Most of these mutations within the virus are so small as to be of little or no significance; others survive and persist and create new variants of the virus. According to the Centers for Disease Control and Prevention (CDC), multiple variants of COVID-19 are currently circulating globally. These are the leading variants being tracked to date:

  • In April 2021, the Delta, or B.1.617 variant, first discovered in India in October 2020, exploded in India. By month’s end, the nation was recording more than 3,000 deaths daily and more than 1 million new cases of COVID-19 every three days. By mid-June 2021, the variant became responsible for 90% of cases in the U.K. and has been linked with a COVID spike there. By July 2021, the Delta variant became the dominant strain in the U.S., leading to high numbers of cases across the country. It appears to be highly contagious and may cause more severe cases than other variants. A recent U.K. study suggests that people infected with the Delta variant may have different symptoms than those identified previously for COVID-19. As of May 2021, self-reports from patients participating in the UK study showed the number one symptom to be headache, followed by sore throat, runny nose and fever. Cough is rarer as is loss of smell and taste. Health officials cautioned individuals not to dismiss these potential COVID-19 symptoms for a bad cold and to take suitable precautions to reduce potential spread should they appear. While breakthrough infections are still rare, some fully vaccinated people are getting infected, especially with high community transmission across the country. Preliminary data suggests that fully vaccinated people who do become infected with the Delta variant can spread the virus to others, according to the CDC. Because of this new evidence, CDC advises that everyone aged 2 or older, including those fully vaccinated, should wear a mask in indoor public spaces, especially in areas with substantial or high transmission. The vaccines do remain very effective against severe illness, hospitalization, and death. Vaccines are still the best tool to protect yourself and your community against the Delta variant.
  • The Alpha, or B.1.1.7, variant was first identified in the U.K. in the fall of 2020. It has since spread to many other countries; it was first reported in the U.S. in Dec. 2020. This variant has spread more easily and quickly than others. In April 2021, the CDC declared the Alpha variant the most dominant COVID-19 virus strain circulating in the United States. Initial information appears to show that the variant is highly contagious and there are concerns it may be more potentially deadly for those infected although research is continuing.
  • The Beta, or B.1.351, variant, first detected in South Africa, emerged independently from the U.K. variant, though it shares some mutations with it. It was originally detected in Oct. 2020 and was first recorded in COVID-19 cases in the U.S. in Jan. 2021.
  • The Gamma, or P.1, variant, was first identified in Japan in early 2021, and detected in travelers from Brazil during a routine screening at an airport. It was first detected in the U.S. in late January 2021. This variant contains a set of mutations that may affect its ability to be recognized by antibodies.

What We Know (from the CDC)

  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 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.

What We Do Not Know

Evidence is limited on how the new COVID-19 variants will affect how COVID-19 vaccines work in real-world conditions. CDC has systems in place to monitor how common these variants are and to look for the emergence of new variants. CDC will continue to monitor variants to see if they have any impact on how COVID-19 vaccines work in real-world conditions.