This recombination mechanism already observed coronaviruses.Comparison coronavirus sequences present nature supports natural origin SARS-CoV-2.Furthermore , SARS-CoV-2 contains trace human-mediated genetic manipulation.More specifically , contain residual sequences related vector systems conventionally used genetic manipulation , suggests indeed product natural random selection.BL4 laboratory , genetic manipulation : reality myths There indeed BL4 laboratory Wuhan : Wuhan National Biosafety Laboratory.Built partnership France , obtained certification 2017.Following SARS epidemics 2002-2004 H1N1 2009 , China wanted improve capacity fight epidemics.The laboratory primarily carries research Ebola , Crimean-Congo hemorrhagic fever SARS.The documented accident linked laboratory working coronaviruses China infection nine individuals April 2004 SARS-CoV-1 virus responsible SARS epidemic 2002-2004 .