This story has been updated.

There are multiple key differences between the coronavirus and influenza despite the viruses having several similarities in symptoms, according to the World Health Organization. 

The global health agency recently detailed what separates the viruses from each other in a situation report

Speed of transmission was reported as the key difference between the viruses. Patients with the flu usually develop symptoms faster than those with COVID-19, allowing the disease to spread faster from one person to the next. 

“Further, transmission in the first 3-5 days of illness, or potentially pre-symptomatic transmission — transmission of the virus before the appearance of symptoms — is a major driver of transmission for influenza. In contrast, while we are learning that there are people who can shed COVID-19 virus 24-48 hours prior to symptom onset, at present, this does not appear to be a major driver of transmission,” the report states.

Additionally, coronavirus appears to be significantly more deadly than the flu based on current data. Though officials believe the true mortality rate of coronavirus will take a while to fully understand, estimates currently show that the crude mortality ration is between 3% and 4%. 

“For seasonal influenza, mortality is usually well below 0.1 [percent]. However, mortality is to a large extent determined by access to and quality of health care,” the report states. 

The report also notes that though children are among the most at-risk groups (elderly, pregnant women and those with underlying conditions) for influenza, that doesn’t appear to be the case when it comes to COVID-19. 

Older people and those with underlying conditions, however, appear to have a higher risk for being diagnosed with the disease. 

“Children are important drivers of influenza virus transmission in the community. For [the] COVID-19 virus, initial data indicates that children are less affected than adults and that clinical attack rates in the 0-19 age group are low,” the report states.