It appears that bat coronaviruses require an intermediate host to attain the potential of becoming a human pathogen10. For 229E these intermediate hosts are likely camelids while SARS-CoV-1, SARS-CoV-2, and MERS-CoV find intermediate zoonotic hosts in civets, dog or pangolin, and camels, respectively10,43. The intermediate host for NL63 is not known. In this context it is interesting that OC43 and HKU1 are the most likely candidates, as the natural host of these viruses are rodents43. The effect of these hosts on the pathogenicity of the coronavirus remains a source of debate. However, the immune systems of dogs, camels, pangolins, rodents, and humans have marked differences—murine B cells for instance express the pattern recognition receptor TLR4, which is absent in human B cells44. Because of these differences in the immune system, it is unlikely that the same evasive strategy can be applied in different species.