Introduction:
SARS-CoV-2 is the cause of coronavirus disease 2019 (COVID-19), first reported in Wuhan, China in late December 2019. As of September 2020, SARS-CoV-2 was responsible for over 25 million cases and nearly one million deaths(1)
Vietnam is a country of 97 million people which, despite its lower-middle income status, managed to limit spread of SARS-CoV-2, requiring eight months to reach 1,000 cases and seven months to record its first fatality. The early days of the pandemic in Vietnam were marked primarily by importations from China whereas the second cluster of cases was characterized by importation from Europe (2–6).
Vietnam hosts two National Influenza Centers (NICs) including one at the National Institute of Hygiene and Epidemiology (NIHE). NIHE coordinates influenza surveillance in northern Vietnam and has played a critical role in responding to the COVID-19 pandemic. In its role as a reference laboratory throughout the country, NIHE received some of the earliest specimens from suspected cases of COVID-19. Our objectives were to describe the virologic characteristics of these specimens received during January through April 2020 and to explore differences in these characteristics among cases derived from different sources.