This is false for two reasons -
- It takes an average of 5–6 days from when someone is infected to when they begin to show symptoms, and
- There are reported cases of infected people not displaying any symptoms of the disease, but they are still infectious during this time. Since transmission occurs mainly through respiratory droplets and such infected people lack this symptom of coughing - how this happens is still being investigated by health authorities.
Therefore, not every person infected with the virus will display symptoms. That's why it's so important to follow these guidelines to stay healthy: https://tinyurl.com/y7asklrf