How long are COVID 19 patients infectious from time of symptom onset

A harvard study similarly found that vaccinated people appear to clear the virus in 5½ days versus.New studies have suggested that people are the most infectious in the 48 hours before they start to experience any symptoms.According to earlier guidance, covid symptoms can appear anywhere from two to 14 days after someone is exposed to the virus.If you are unable to wear a mask when around others, you should continue to quarantine for 10 days.The greatest risk of transmission was 2 days before and 3 days after the index patient became ill, peaking on the day of symptom onset (adjusted relative risk [arr], 1.3).

Ideally, patients should be quarantined at home or at an institution for 2 weeks after the symptoms completely disappear.Another study, which looked at 77 pairs of individuals in which one person infected the other, found that contagiousness both began and peaked before the first symptoms of illness — 2.3 days and 0.7 days respectively.The most infectious period is thought to be 1 to 3 days before symptoms.