Current estimates of the incubation period range from 1 to 14 days, according to the World Health
Organization and the US Centers for Disease Control and Prevention.[32] [33] The median incubation period
has been estimated to be 5 days.[18] Transmission may be possible during the incubation period.[34]
Preliminary reports suggest that the reproductive number (R₀), the number of people who acquire the
infection from an infected person, is approximately 2.2.[18] [35] However, as the situation is still evolving, the
R₀ may actually be higher or lower.
While the pathophysiology of this condition is currently unknown, a structural analysis suggests that the virus
may be able to bind to the angiotensin-converting enzyme-2 (ACE2) receptor in humans, which suggests
that it may have a similar pathogenesis to SARS.[17] However, a unique structural feature of the spike
glycoprotein receptor binding domain of SARS-CoV-2 (which is responsible for the entry of the virus into host
cells) confers potentially higher binding affinity for ACE2 on host cells compared to SARS-CoV.[36] A furinlike cleavage site has been identified in the spike protein of the virus; this does not exist in other SARS-like
coronaviruses
High viral loads have been detected in nasal and throat swabs soon after symptom onset, and it is thought
that the viral shedding pattern may be similar to that of patients with influenza. An asymptomatic patient was
found to have a similar viral load compared with symptomatic patients