The incubation period for COVID-19-the time between exposure to the virus and the appearance of symptoms-averages around 5 days. Symptoms typically emerge anywhere from 2 to 14 days after infection, with most people developing symptoms by day 12 to 14
. The incubation period varies by variant:
- Original Alpha variant: about 5 days
- Beta variant: about 4.5 days
- Delta variant: about 4.3 days
- Omicron variant: about 3 to 4 days
This shortening of the incubation period with newer variants means people can become contagious and spread the virus sooner after exposure
. During the incubation period, individuals can already be contagious, even before symptoms appear, which contributes to the spread of COVID-19
. In summary:
- Average incubation period: ~5 days
- Range: 2 to 14 days
- Variant-dependent incubation period, with Omicron having the shortest
- Contagiousness begins about 2 days before symptom onset
These findings support quarantine recommendations of up to 14 days after exposure to prevent further transmission
