Abstract
The isolation of infected individuals and quarantine of their contacts are usually employed to mitigate the transmission of SARS-CoV-2. Although 14-day isolation of infected individuals could effectively reduce the risk of subsequent transmission, it also substantially impacts the patient’s psychological and emotional well-being. It is, therefore, vital to investigate how the isolation duration could be shortened when effective vaccines are available. Here, an individual-based modeling approach was employed to estimate the likelihood of secondary infections and the likelihood of an outbreak following the isolation of a primary case for a range of isolation periods. Our individual-based model integrated the viral loads and infectiousness profiles of vaccinated and unvaccinated infected individuals. The effects of waning vaccine-induced immunity against infection were also considered. By simulating the transmission of the SARS-CoV-2 Delta (B.1.617.2) variant in a community, we found that in the baseline scenario in which all individuals were unvaccinated and nonpharmaceutical interventions were not used, there was an approximately 3% chance that an unvaccinated individual would lead to at least one secondary infection after being isolated for 14 days, and a sustained chain of transmission could occur with a less than 1% chance. With the outbreak risk equivalent to that of the 14-day isolation in the baseline scenario, we found that the isolation duration could be shortened to 7.33 days (95% CI 6.68-7.98) if 75% of people in the community were fully vaccinated with the BNT162b2 vaccine within the last three months. In the best-case scenario in which all individuals in the community are fully vaccinated, isolation of Delta variant-infected individuals may no longer be necessary. However, to keep the outbreak risk lower than 1%, a booster vaccination may be necessary three months after full vaccination.
【초록키워드】 BNT162b2 vaccine, vaccination, quarantine, variant, Infection, Delta, B.1.617.2, risk, Transmission, Secondary infection, Viral load, outbreak, Impact, Isolation, Community, Psychological, booster vaccination, nonpharmaceutical intervention, Contact, Vaccine-induced immunity, emotional, 95% CI, profile, infected individual, infected individuals, individual, transmission of SARS-CoV-2, Effect, mitigate, approach, likelihood, the patient, subsequent, less, occur, effective vaccine, reduce, sustained, baseline, the SARS-CoV-2, 【제목키워드】 COVID-19, vaccination, Isolation, Community, reveal,