The omicron variant has given rise to the stealthiest of subvariants: the BA.5. Currently, this relatively new mutation is behind a majority of the nearly 125,000 cases reported on August 16.

But due to the popularity of at-home tests and COVID fatigue, cases are largely underreported. In fact, a recent study, conducted by researchers at the L.A.-based Cedars-Sinai Medical Center, showed most people who were infected with COVID-19 didn’t even know they had the virus.

These undiagnosed infections could be why the variant spreads quickly, researchers ascertained in the study published in the journal JAMA Network Open.

Out of nearly 2,500 blood samples from patients collected before the omicron surge, researchers identified 210 people who probably had a COVID-19 infection.

“More than one in every two people who were infected with omicron didn’t know they had it,” Sandy Y. Joung, the study’s first author and an investigator at Cedars-Sinai, said in a press release. “Awareness will be key for allowing us to move beyond this pandemic.” 

Omicron symptoms are less severe than symptoms from previous variants and typically encompass fatigue, cough, headache, sore throat and a runny nose.

“Our study findings add to evidence that undiagnosed infections can increase transmission of the virus,” said Joung. “A low level of infection awareness has likely contributed to the fast spread of Omicron.”

Through health surveys and interviews, the researchers found:

  • An estimated 44% of participants with new infections knew they had COVID-19.
  • But a majority (56%) of participants were unaware of their recent infection.
  • And 10% thought they had a cold or a different type of infection.

What are the updated quarantine guidelines?

Now, vaccinated and unvaccinated individuals are no longer required to quarantine after exposure but are recommended to mask up for 10 days or until they test negative, as I previously reported.

“We’re in a stronger place today as a nation, with more tools — like vaccination, boosters, and treatments — to protect ourselves, and our communities, from a severe illness from COVID-19,” said Dr. Greta Massetti, the CDC’s Morbidity and Mortality Weekly Report author, in a press release issued by the CDC.

Can you protect yourself against omicron?

The Centers for Disease Control and Prevention has said there is no evidence that the two new subvariants BA.4 and BA.5 are more severe than others, but it is clear that immunity acquired through previous infection or vaccination is not as effective against them, as I previously reported.

Dr. Sandra Adams, a professor of biology and virologist at Montclair State University, told NJ Advance Media that the newer mutations allow new strains to evade antibodies. “However, vaccines and previous infections still provide protection from serious disease,” she said.