Lam Quang Ngon

1 INTRODUCTION The COVID-19 pandemic, with more than 700 million cases and 7 million deaths, was caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (Wu et al., 2020). More than 4 years after the first cases detected in Wuhan (Hubei province, China) in December 2019, the origin of SARS-CoV-2 still remains unresolved.

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