Incubation vs Infectious Period

Incubation Period: The time from when someone is infected to when symptoms develop. Based on existing evidence-based research, the incubation period of SARS-CoV-2 and other coronaviruses (e.g. MERS-CoV, SARS-CoV) ranges from 2–14 days. 50% of people will become ill 5 days after infection.

Infectious Period: The time when an infected person, who may not be showing symptoms, can transmit the virus to others. While it varies from person to person, it is typically ~ 7 days.

Begins: 

2 days before the start of signs/symptoms

Ends:

  1. 10+ days after illness onset and
  2. symptoms are improving and
  3. there has been no fever within the past 24 hours (without anti-pyretic medications).

Some immunocompromised individuals or those with severe COVID-19 may shed the virus for 20 days.

For asymptomatic individuals, it is more difficult to define their infectious period.