Since the novel Coronavirus was introduced, scientists and healthcare professionals have been working tirelessly to give the public more information. You may have been in contact with someone who contracted the infamous virus, but how long does it take for COVID-19 symptoms to appear? When Is Someone Most Contagious With COVID-19? If an individual is infected or exposed to the virus, contagion can begin up to 48 hours before symptoms appear. However, the person is ...