The incubation period for individuals infected with the Omicron variant may be around 72 hours, which is shorter than that of other variants, according to a new study recently published by the CDC in the United States.
Individuals infected with Omicron may exhibit symptoms, test positive, and potentially spread the virus to others within just 3 days, shorter than the 4-6 days observed with the Delta variant and the original strain, as reported in a study released by the Centers for Disease Control and Prevention (CDC) on December 28, according to the New York Times.
The study was conducted on a cluster of Omicron infections involving 6 individuals aged 11-48 from the same household in Nebraska, USA, including a 48-year-old man who was unvaccinated and had recently traveled to Nigeria.
A woman testing for Covid-19 on December 22 in New York (USA), as Omicron spreads rapidly in the country.
These individuals were confirmed to be infected with Omicron on December 2, but they had been suspected of having Covid-19 several days before the US confirmed its first case of the new variant on December 1.
Only one person in this household was fully vaccinated. Five out of the six individuals, including the man who returned from Nigeria, had contracted Covid-19 in 2020. None had underlying health conditions.
The study also indicated that these six individuals experienced mild symptoms. All six described their level of illness this time as equivalent to or milder than their first experience with Covid-19.
“The five cases of reinfection, including one fully vaccinated individual, may be due to waning immunity, the ability of Omicron to partially evade immunity, or both,” the authors of the study wrote.
“It is currently unclear whether the reason for the milder clinical syndromes or the different symptoms is due to the existing level of immunity or a change in the clinical characteristics of Omicron,” the authors noted.
Previously, a study in Norway conducted on a large Omicron outbreak following a Christmas party also indicated that the incubation period for this variant is around 3 days. It remains unclear how long patients may be able to spread the virus to others.
