Yet virus pandemic potential exceedingly rare , said . `` If viruses really frequent , would dead coronaviruses , '' Andersen said . `` We would coronavirus pandemics time.We n't , pop every 10 years , average . `` Rasmussen said plausible scenario `` natural zoonotic spillover , '' adding serology studies shown people China living near bat caves antibodies bat SARS-like coronaviruses blood , `` suggesting people exposed related viruses course daily lives , ’ implausible SARS-CoV-2 emerged humans chance encounter human wild bat animal . `` Doubts ever pinpointing origin Perlman said scientists may never able track origins virus intermediary host . `` I think 's really important issue , figuring virus comes , 's hard business finding , '' said .