Dear editor,
Recently, a letter in your journal predicted that the SARS-CoV-2 Omicron strain will thereby replace the Delta variant as the dominant strain.1 This prediction has become ever more salient due to the new wave of COVID-19 outbreaks that has occurred in China. This round of epidemic is mainly caused by the Omicron subtype BA.2. Since the day when the first Omicron cases were confirmed and reported to April 3rd 2022, more than 100-thousand people had been infected. The current epidemic in China is unique in its extremely high infection rate as well as the high frequency of its outbreaks over the entire country, which has caused serious challenges in the prevention and control of the epidemic.
Compared with the original and the Delta strains, the replication ability of the BA.2 strain in the lungs is greatly reduced, rendering the virus’ pathogenicity greatly weakened.This has resulted in symptoms that are milder than influenza and close to the level of the common cold.2 The hospitalization rate and ICU rate of infected persons have decreased, and the median period of hospitalization has also decreased.3 Nevertheless, the BA.2 strain has become extremely infectious—the R0 may be as high as 9. Even with the lower pathogenicity and fatality rate, the mortality rate will increase significantly when a large-scale outbreak occurs, with the death concentrated among the elderly, especially those who have comorbidities and yet to be vaccinated.4 Recent lessons from Hong Kong exemplify this phenomenon, indicating that improving vaccination rates among the older population should be a high priority5 (Figs. 1 and 2 ).
Fig. 1.
Weeky comfirmed cases and asymptomatic cases in China from December 13, 2021 to April 3, 2022. Data for all cases are from National Health Commission of the People's Republic of China (http://www.nhc.gov.cn).
Fig. 2.
Geographical distribution of confirmed cases of COVID-19 in China from December 13, 2021 to April 3, 2022, except Macao, Hongkong and Taiwan. Data for all cases are from National Health Commission of the People's Republic of China (http://www.nhc.gov.cn).
On March 31st, a total of 3.27 billion doses of the novel coronavirus vaccines were purportedly distributed nationwide, with the total number of fully vaccinated people reaching 1.27 billion. This means that around 90.47% of the total population have been vaccinated and 90.63% of people have completed the booster immunization in China. In addition, 223.708 million elderly people over the age of 60 have received the vaccination, 95% of whom have been fully vaccinated. In some provinces, the vaccination rate of elders has reached over 85%.
Learning from the findings of a large number of medical research and clinical practices and considering the dynamics in the domestic and global epidemic situation, the National Health Commission and the State Administration of Traditional Chinese Medicine issued the “Novel Coronavirus Pneumonia Diagnosis and Treatment Plan (Trial Version 9)” to deal with the new outbreak of asymptomatic infected individuals with Omicron variant and a high number of mild cases in China. In conjunction with the aforementioned changes in treatment protocols, several measures have been implemented to deal with Omicron in China in order to more efficiently implement the “Dynamic zero” policy. Firstly, the Paxlovid treatment tablets have been distributed to the frontline, with the hope of reducing hospital admissions and deaths among high-risk individuals.6 Secondly, in order to further improve the effectiveness of early detection of infected persons, the antigen test kits have been added to the detection protocol so as to reduce the testing pressure for local laboratories. Lastly, 19 provinces have established mobile cabin hospitals to isolate infected people. Economic centers such as Shenzhen and Shanghai have even implementedd a complete lockdown of the city to stifle the spread of Omicron.
In addition to the several measures have been announced to deal with Omicron, the government should continue implementing the following measures: 1) Studies have shown that a third dose of vaccination could greatly improve the protection rate, thus the government should continue promoting further vaccination in the future in order to maintain the level of community immunity. 2) Epidemic prevention policies should be designed in a way that would not overburden current medical systems whilst ensuring that patients suffering from basic illness, cancer and other diseases would receive the timely treatment and care they deserve. 3) “Dynamic zero” policy should remain in place. The symptoms caused by Omicron infection are mild, hence the public won't be as cautious as they used to be. The government should respond to the concept of coexistence with the virus rationally and put the safety of the people in the first place by educating the public on the potential harm of Omicron strains. 4) Strict mobility policy should be executed to limit the movement of people in medium to high-risk areas for the purpose of preventing the spread of the virus. In summary, as the SARS-CoV-2 continues mutate, the Chinese government should be more vigilant and adjust virus prevention policy dynamically and accordingly to avoid further epidemic of outbreaks while minimizing economic losses. In the near future, when China successfully overcomes Omicron even other variant strains, other countries may learn from China's “Dynamic zero” policy and successfully eliminate SARS-CoV-2 epidemics in the world together.
Declaration of Competing Interest
None.
Acknowledgments
This work was supported by the Guangdong Provincial Special Fund for Modern Agriculture Industry Technology Innovation Teams (No. 2022KJ119) and the Scientific and Technological Research Project of Foshan (No. 2020001000151). We thank Siyuan Hu at the University of Wisconsin-Madison for his editing work.
References
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