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Can Asymptomatic People Spread Omicron?

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Key Takeaways

  • The BA.2 subvariant of Omicron is highly contagious and has high rates of asymptomatic transmission.
  • Asymptomatic people can still spread COVID-19.
  • This stresses the importance of testing and following isolation/quarantine procedures.

Omicron and its subvariants like BA.2 are spreading across the United States, with cases increasing by about 33% between April 18 and April 25.

The BA.2 variant now accounts for 68% of COVID cases in the United States, and like Omicron, has been associated with mild or oftentimes no symptoms in people who test positive and are vaccinated.

But if you have no symptoms, can you still spread Omicron and other variants? Experts say yes.

“Asymptomatic carriers of COVID are more likely to spread the virus largely because they are less likely to be wearing a mask or quarantining if they don’t have symptoms,” Abraar Karan, MD, MPH, infectious disease fellow in the Division of Infectious Diseases and Geographic Medicine at Stanford Medicine, told Verywell. “Also, by the time you are showing symptoms, you may be entering an inflammatory phase more than the infectious phase.”

Increasing Asymptomatic Spread of COVID-19

A recent study shows that BA.2 has a significantly increased rate of asymptomatic transmission compared to previous COVID variants, including the Delta variant, mainly because many people with an Omicron infection do not develop symptoms. This has led to reduced quarantine times and social distancing precautions.

The Centers for Disease Control and Prevention (CDC) states that anyone who is infected with Omicron, regardless of vaccination status, can spread the virus, even if they don’t develop any symptoms.

A systematic review published in late 2021, when the Omicron variant began its worldwide spread, estimated that around 40% of positive COVID infections were asymptomatic, triggering a new surge of cases in 2022 that has led to almost 26 million new COVID cases.

When Should You Get Tested?

As Omicron cases continue to spread, COVID-19 testing is still a key defense in halting the spread of asymptomatic cases. The CDC recommends getting tested under the following circumstances:

  • You have COVID-19 symptoms
  • Five days after you have been exposed to someone who tested positive (6 feet for 15 minutes or longer within a 24 hour period)
  • For mandated screenings (work, school, large gatherings, etc.)
  • Before and after travel
  • When asked by a healthcare professional or public health official

After months of low supply, self-testing rapid COVID tests are now readily available on many pharmacy and store shelves. You can also receive free tests in the mail by registering at Covid.gov.

COVID-19 testing sites and healthcare facilities are authorized to administer polymerase chain reaction (PCR) tests that are sent to an off-site laboratory for result confirmation. While these tests typically take a few days to come back, the results are more accurate than a rapid test.

What This Means For You

If you test positive for COVID-19 it is important to isolate yourself for five days in your home, even if you don’t show any symptoms. Administer an at-home rapid test or get a PCR test from a local clinic if you have been exposed to someone with COVID and or are exhibiting symptoms of the virus.

What to Do When You Test Positive

If you test positive for COVID-19, it is important to quarantine regardless if you have symptoms or not. This also pertains to those that are vaccinated.

The CDC outlines the following isolation measures for COVID-19 positive cases:

  • Stay home and away from others for at least 5 full days
  • Wear a mask if you have to be around others
  • Do not travel
  • Day zero is the first day of a positive viral test or the first day of symptoms
  • Take precautions until day 10 (wear a mask, avoid travel, avoid vulnerable people)

Mitigating the spread of asymptomatic cases is critical in slowing the spread of COVID-19. The World Health Organization (WHO) confirms that COVID-19 spreads more easily in confined, poorly ventilated areas and encourages people to consider three things when deciding what social events to attend:

  • Crowded places
  • Close-contact settings (close conversations)
  • Confined spaces that have poor ventilation

“I advise watching wastewater data, and adjusting your behavior when case rates are high in your area, including avoiding big, crowded events,” Karan said.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.

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9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Centers for Disease Control and Prevention. Monitoring variant proportions.

  3. Garrett N, Tapley A, Andriesen J, et al. High asymptomatic carriage with the Omicron variant in South Africa. Clin Infect Dis. Published online March 30, 2022. doi.org/10.1093/cid/ciac237

  4. Centers for Disease Control and Prevention. Omicron variant: what you need to know.

  5. Ma Q, Liu J, Liu Q, et al. Global percentage of asymptomatic SARS-CoV-2 infections among the tested population and individuals with confirmed COVID-19 diagnosis: a systematic review and meta-analysis. JAMA Netw Open. 2021;4(12):e2137257. doi:10.1001/jamanetworkopen.2021.37257

  6. Centers for Disease Control and Prevention. COVID-19 testing: What you need to know.

  7. Centers for Disease Control and Prevention. Self-testing at home or anywhere.

  8. Centers for Disease Control and Prevention. Quarantine and Isolation. Updated March 30, 2022.

  9. World Health Organization. Coronavirus disease (COVID-19): how is it transmitted?