hCoV-19/Wuhan/WIV04/2019 (WIV04) is the official reference sequence employed by GISAID (EPI_ISL_402124). WIV04 was chosen because of its high-quality genome sequence and because it represented the consensus of a handful of early submissions for the betacoronavirus responsible for COVID-19. (Pilailuk et al 2020)

WIV04 is representative of and identical to the early outbreak sequences. WIV04 was isolated by the Wuhan Institute of Virology from a clinical sample of a bronchoalveolar lavage fluid (BALF) collected at the Wuhan Jinyintan Hospital in Hubei Province on 30^th December 2019 from a symptomatic patient, a retailer working at the Huanan Seafood Wholesale Market.

BALF was used for RNA extraction and metagenomic next-generation sequencing (NGS). The consensus sequence was obtained by de-novo assembly. (Zheng-Li Shi et al 2020)