The ongoing pandemic of coronavirus disease 2019 (COVID-19) caused by the novel virus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has claimed many lives worldwide. To combat the pandemic, multiple types of vaccines are under development with unprecedented rapidity. Theoretically, future vaccination against COVID-19 may fall into long-term costly guerrilla warfare between SARS-CoV-2 and humans. Elimination of SARS-CoV-2 through vaccination to avoid the potential longterm costly guerrilla warfare, if possible, is highly desired and worth intensive consideration. Human influenza pandemics emerging in 1957, 1968, and 2009 established strong global herd immunity and led to the elimination of three human influenza viruses, which circulated worldwide for years before the pandemics. Moreover, both clade 7.2 of subtype H5 highly pathogenic avian influenza virus and subtype H7N9 avian influenza virus circulated in poultry in China for years, and they have been virtually eliminated through mass vaccination in recent years. These facts suggest that the rapid establishment of global herd immunity through mass vaccination using an appropriate vaccine could eliminate SARS-CoV-2. The coming 2 years are a golden time for elimination through vaccination, which requires tremendous national and international collaboration. This review also prioritizes the efficacy of vaccines for COVID-19 and elucidates the importance of the development of more live vaccines for COVID-19.

The whole world has entered a terrible crisis with a huge and increasing amount of human deaths and economic loss in fighting the pandemic of COVID-19 caused by the novel coronavirus termed SARS-CoV-2. The live pathogen vaccine (LPV) strategy, which originated in ancient China for fighting smallpox, has been applied successfully in the USA military recruits for decades to control acute respiratory diseases caused by types 4 and 7 adenoviruses. This strategy has also been widely employed in veterinary medicine. These facts suggest a fast way out of the current pandemic crisis, namely that SARS-CoV-2 could be directly used as a live vaccine. Beyond the two traditional mechanisms to guarantee the LPV's safety (SARS-CoV-2 is not highly pathogenic; the LPV is inoculated bypassing the respiratory sites of pathology), three novel mechanisms to further ensure the LPV's safety are available (the virus replication is inhibited with early use of an antiviral drug; symptomatic LPV recipients are cured with convalescent plasma; the LPV is inoculated in hot seasons). This LPV strategy has multiple potential advantages over other options, and could reduce This article is protected by copyright. All rights reserved. Accepted Articlegreatly the morbidity and mortality as well as economic loss caused by the pandemic. The safety and efficacy of this strategy should be investigated strictly using animal experiments and clinical trials, and even if the experiments and trials all support the strategy, it should be implemented with enough cautiousness. Highlights The world has entered a terrible crisis in fighting the COVID-19 pandemic  Live pathogen vaccines (LPV) defeated infectious disease caused by adenoviruses  The LPV strategy has been widely employed in veterinary medicine  The LPV strategy could be a way out of the COVID-19 pandemic crisis  Five mechanisms can be employed to ensure the safety of the LPV of SARS-CoV-2  The LPV strategy should be examined with animal experiments and clinical trials