Study on Effects of COVID-19 Infection on Vaccinated Persons

Mr Gan Thiam Poh asked the Minister for Health (a) in respect of fully vaccinated individuals who have tested positive for COVID-19 locally, what are their average recovery times; (b) whether the Ministry has conducted any study of the duration of COVID-19 infection in these individuals; and (c) if so, whether such study also confirms that the risk of transmission between fully vaccinated individuals is lower as compared to unvaccinated individuals.

Mr Ong Ye Kung: Fully vaccinated patients recover faster and are infectious for a shorter period. Based on a recent study of local cases by the National Centre for Infectious Diseases (NCID), viral levels in vaccinated patients can decline to undetectable or non-infectious levels within 10 days after illness onset. This takes around 15 days, on average, for unvaccinated patients. However, during the infectious period, vaccinated and non-vaccinated patients are equally likely to transmit to others.