If i am infected with Omicron, when am i contagious?
The answer to this question is not yet clear, but some early data suggests that people may become contagious earlier than with earlier variants, possibly within a day of infection.
The United States Centers for Disease Control and Prevention says people with coronavirus are most contagious in the days before and after COVID-19 symptoms develop. But that window could happen sooner with Omicron, according to some scientists outside the agency.
That’s because Omicron seems to cause symptoms faster than previous variants – around three days after infection, on average, according to preliminary studies. Based on previous data, this means that people with Omicron could start to become contagious as soon as a day after infection.
With the earlier variants, people became contagious two to four days after infection. And people remain contagious for a few days after symptoms subside.
Researchers say it’s too early to know whether this shorter incubation period for Omicron results in earlier contagiousness. But that would help explain the rapid spread of the variant.
Dr Amy Karger of the University of Minnesota School of Medicine recommends that people test themselves three days and five days after exposure, if possible.
“A lot of people get positive by day three,” Karger said, referring to those infected with Omicron. “There is basically an opportunity here to catch people sooner than you would with the other variations.”
If you only have one test, it’s fine to wait until the fifth day, Karger says.
People who show symptoms of COVID-19 should get tested immediately, if possible.
Tests developed in the lab are more sensitive than rapid tests, so they should be able to detect the virus on the third day after exposure, if not sooner.
People who don’t develop symptoms typically have much lower viral levels, so it’s much less clear when – or if – they become contagious.
Still, those who test positive but don’t have symptoms should self-isolate for at least five days, according to the latest CDC guidelines. The agency has been criticized for not requiring a negative test before leaving solitary confinement; the CDC says this step should be optional.
People with symptoms of COVID-19 should remain isolated until they are free from fever for at least 24 hours.