Laboratory tests of 15 bat coronavirus spike proteins found that relatives closest to SARS-CoV-2 could use receptors from more animal species and were more readily neutralized by existing antibodies. Other viral groups showed narrower receptor use. Receptor use and antibody recognition are two factors relevant to spillover risk; the tests do not demonstrate infection or transmission in people.
A PLOS Biology study compared 15 bat sarbecovirus spike proteins against ACE2 receptors from 34 animal species. The panel included 16 bat species and 18 other mammals. Binding and cell-entry tests found that viruses closest to SARS-CoV-2 more often used a broad range of receptors, while several other groups showed narrower patterns.[1], [2]
Viruses in the group containing SARS-CoV-2 and related viruses from Laos often had broader receptor use. A RhGB07 example from another group was more restricted; determining its spike structure helped identify receptor-binding features. Omicron-lineage changes also shifted some laboratory patterns of receptor use across species.[1]
The team tested sera from people who had recovered from SARS-CoV-2 and monoclonal antibodies from people infected after vaccination. Cross-neutralization was strongest against viruses closest to SARS-CoV-2. More distant relatives showed broader but limited activity. The receptor and antibody results therefore need to be considered together.[1]
The assays measure receptor binding, entry through spike-bearing test particles and antibody responses under laboratory conditions. They do not show efficient transmission between animals, natural infection of humans or disease in a person. Exposure, other viral functions and immune conditions also influence spillover. The findings provide a map for further research into host range and cross-reactive immunity, rather than evidence that another outbreak will occur.[1]
