To the Editor—As countries around the world gradually relax their prevention and control policies against COVID-19 and choose to co-exist with the virus, China has also ended its strict zero COVID policy. This followed debates that centered on whether China should insist on the zero-COVID strategy or switch to a more open strategy. The zero-COVID strategy was to detect and control cases as early as possible and to cut off transmission at the community level by taking stringent control measures such as large-scale nucleic acid testing, compulsory case isolation, rapid tracing and quarantine of close contacts. The major challenge of continuing with the zero-COVID strategy was that economic recovery might be delayed 1, 2, and so it was unclear for how long that this strategy could be maintained for 3, 4. The greatest concern from ending the zero-COVID strategy is that COVID-19 cases will surge rapidly 5, which may result in failure of the healthcare system and massive loss of life, notwithstanding the relatively low pathogenicity of the Omicron variant 6.

In principle, containment measures such as closing public facilities, enforcing wearing masks and maintaining social distancing could be fine-tuned, but implementation of this faces challenges. Hong Kong failed to prevent an outbreak of the Omicron variant at the start of 2022, which was followed by a large number of infections in Shanghai, Jilin, and in other regions of China 7. If the zero-COVID strategy is ended in all regions of China simultaneously, the surge of infections could cause a collapse of the healthcare system, including a shortage of healthcare workers and intensive care unit beds.