Assessing the feasibility of sustaining SARS-CoV-2 local containment in China in the era of highly transmissible variants

Abstract

Background The SARS-CoV-2 containment strategy has been successful in mainland China prior to the emergence of Omicron. However, in the era of highly transmissible variants, whether it is possible for China to sustain a local containment policy and under what conditions China could transition away from it are of paramount importance at the current stage of the pandemic. Methods We developed a spatially structured, fully stochastic, individual-based SARS-CoV-2 transmission model to evaluate the feasibility of sustaining SARS-CoV-2 local containment in mainland China considering the Omicron variants, China’s current immunization level, and nonpharmaceutical interventions (NPIs). We also built a statistical model to estimate the overall disease burden under various hypothetical mitigation scenarios. Results We found that due to high transmissibility, neither Omicron BA.1 nor BA.2 could be contained by China’s pre-Omicron NPI strategies which were successful prior to the emergence of the Omicron variants. However, increased intervention intensity, such as enhanced population mobility restrictions and multi-round mass testing, could lead to containment success. We estimated that an acute Omicron epidemic wave in mainland China would result in significant number of deaths if China were to reopen under current vaccine coverage with no antiviral uptake, while increasing vaccination coverage and antiviral uptake could substantially reduce the disease burden. Conclusions As China’s current vaccination has yet to reach high coverage in older populations, NPIs remain essential tools to maintain low levels of infection while building up protective population immunity, ensuring a smooth transition out of the pandemic phase while minimizing the overall disease burden.

Retrospective Modeling of the Omicron Epidemic in Shanghai, China: Exploring the Timing and Performance of Control Measures

“…Our findings highlight the failure of the precise containment measures implemented in Shanghai in March to stop the spread of the outbreak. If appropriate measures are not implemented within an optimal intervention time, the window period will be missed, leading to high caseloads as well as resource crowding in testing and contact tracing capacity, and further leading to a decline in the effectiveness of targeted interventions and faster epidemic growth [ 41 ]. If strong measures are implemented in a short period, they could prevent a pandemic.…”

“…If strong measures are implemented in a short period, they could prevent a pandemic. Studies have proposed how containment could be achieved and maintained in China, mainly including accelerating case identification and preventing onward transmission [ 41 , 42 ]. A major strength of this paper is that the model takes into consideration the proportion of presymptomatic cases identified at each period and the proportion of unascertained presymptomatic cases under control, which can reflect the effectiveness of prevention and control at each stage of the epidemic in Shanghai from the side.…”

Is it possible to flatten-the-curve after the initial outbreak of Covid-19? A data-driven modeling analysis for Omicron pandemic in China

“…In some countries, the negative impact of COVID-19 has somehow reduced; however, although less infection rates were achieved, the zero-COVID policy is still applied in China 9 . Completely eradicating the pandemic within the shortest possible time is the safest method to protect the older population as the application of high-risk policy will further prolong the pandemic.…”

A Four-Channel Surface Plasmon Resonance Sensor Functionalized Online for Simultaneous Detections of Anti-SARS-CoV-2 Antibody, Free Viral Particles, and Neutralized Viral Particles

“…29 Third, an unequivocal diagnosis in a single test is more cost-effective and can help reduce the number of visits to hospitals or testing centers. 30 SPR, a sensitive and real-time method, has emerged as a suitable platform for clinical assays. 31−35 Obviation of the use of enzymes or fluorophores for signal readout cuts down the assay cost and simplifies the procedure.…”

“…Such information is especially useful to vaccine development . Third, an unequivocal diagnosis in a single test is more cost-effective and can help reduce the number of visits to hospitals or testing centers …”