Modeling results were based on the percent of 2019 travel into Guangdong that occurs using the percent infected from real world data near the end of 2021 — 20%, 50%, and 100% of 2019 travel into Guangdong, called travel recovery.
Containment: With 2022 incoming travel at a 20% recovery of 2019 travel, a containment strategy controls the maximum number daily infections at low level (Figure 3), with annual cases and deaths of 215 and 2 (Figure 4). As booster dose coverage increases, daily cases become lower (Figure 3). With higher percentages recovery of 2019 travel, the epidemic is still controlled by containment.
Projected daily new COVID-19 local cases under different NPI lifting scenarios in Guangdong Province in 2022.
Note: A log10
transformed y-axis was used in this figure. 1) containment strategy: 14 days border quarantine of incoming travelers, use of personal protection and social distancing, sensitive measures for infection detection (fever monitoring and contact tracing); 2) suppression: 7 days border quarantine, use of personal protection and social distancing, sensitive measures for infection detection; 3) mitigation: no border quarantine for travelers, use of personal protection and social distancing, routine measures for infected persons detection (fever monitor without contact tracing); 4) coexistence: no border quarantine, no personal protection, no social distancing, routine measure for infected persons detection (no contact tracing). Abbreviations: COVID-19=coronavirus disease 2019; NPI=non-pharmacological interventions.
Cumulative number of local COVID-19 cases and deaths, and the maximum required number of hospital beds, ICU beds, and hotel rooms for border quarantine under different scenarios. (A) Cumulative cases; (B) Cumulative deaths; (C) Required hospital beds (all infected persons hospitalized); (D) Required hospital beds (severe infected persons hospitalized); (E) Required ICU beds; (F) Required hotel rooms for imported quarantine.
Note: The grey dashed lines refer to the current capacity of medical resources in Guangdong Province. PP&SD refer to personal protection and social distancing; FC refers to fever clinic monitor; CC refers to close contact tracing; 20%, 50% and 100% refer to 20%, 50% and 100% travel recovery compared with 2019 incoming overseas travel. Abbreviations: COVID-19=coronavirus disease 2019; ICU=intensive care unit.
Suppression: With 20% recovery of travel, a suppression strategy controls the maximum daily infections at 7 (Figure 3), with 1,397 total cases and 13 deaths (Figure 4). If booster dose uptake is 85%, the maximum daily number of local infections decreases to 2. With 50% and 100% of travel recovery, the cumulative number of cases is projected to become 3,547 and 7,277.
Mitigation: With 20% recovery of travel, a mitigation strategy results in a maximum of 63 infections per day, with 21,722 total cases and 205 deaths. A booster dose coverage of 85% reduces the maximum daily infections to 22. However, 50% and 100% travel recovery yields 55,205 and 113,519 total cases in Guangdong.
Coexistence: If most NPIs are lifted, 20% travel recovery brings the projected daily maximum of cases to 75,716, with annual cases and deaths of 6,850,083 and 64,626. With 50% and 100% travel recovery, Guangdong would suffer 10,081,389 or 12,922,032 cases in 2022.
Containment: At 20% travel recovery, at the peak of epidemic, 1,398 infected people, including locals and incoming travelers, will require quarantine and isolated treatment. Infected individuals are always hospitalized in China, implying the need for 1,398 hospital beds at epidemic peak. If only severe cases are hospitalized, 55 hospital beds and 5 ICU beds will be needed, but 90,448 hotel rooms will be needed for border quarantine. With 50% and 100% travel recovery, the peak needs for treatment will be 3,496 and 6,995 hospital beds and 226,119 and 452,238 quarantine rooms, respectively.
Suppression strategy: At 20% travel recovery, at the peak of the epidemic, 1,454 hospital beds will be needed. If only severe cases are hospitalized, 58 beds will be needed. Compared to containment, suppression requires fewer hotel rooms for imported quarantine (45,458), which is within Guangdong’s capacity. With 50% and 100% travel recovery, 3,639 and 7,295 hospital rooms will be needed at epidemic peak, and 113,645 and 227,289 quarantine hotel rooms will be needed, respectively.
Mitigation: With 20% travel recovery, 3,498 hospital beds will be needed at peak if all infected individuals are hospitalized; 170 hospital beds will be needed if only severe cases are hospitalized. A peak of 29 ICU beds would be needed. With travel recovery of 50% and 100% levels, 8,778 and 17,664 hospital beds will be needed.
Coexistence: With 20% travel recovery, 1,492,867 hospital beds would be required at peak. If only severe cases are hospitalized, 82,231 hospital beds will be required. With 50% and 100% travel recovery, Guangdong would have to arrange 2,389,533 and 3,249,552 hospital beds for treatment of infected individuals.
As shown in Supplementary Table S4, the epidemic would require more medical resources with slower booster vaccination progress. More sensitive infection detection measures would slow the epidemic.