Prior COVID-19 exposure may provide cross-protection against related bat coronavirus threats
Researchers from The Pirbright Institute and King's College London discovered that people with COVID-19 immunity from infection or vaccination are more likely to be protected against closely related bat sarbecoviruses that could pose future spillover risks. The team found that bat coronaviruses most capable of infecting multiple animal species are also those most closely related to SARS-CoV-2 and most likely to be recognized by existing COVID-19 immunity. This suggests widespread human exposure to SARS-CoV-2 may have raised the barrier for related viruses to establish themselves in human populations.
The research examined how diverse bat coronaviruses interact with ACE2 receptors, the protein that many coronaviruses use to penetrate cells. Scientists tested 15 different bat coronavirus spike proteins against ACE2 variants from 34 species to determine which viruses could infect the widest range of hosts. The analysis revealed that viruses sharing close evolutionary ties to SARS-CoV-2 possessed a distinctive ability to use ACE2 receptors across many animal species, while more distantly related bat coronaviruses showed limited host flexibility.
In parallel testing, antibodies from COVID-19 recovered patients successfully neutralized closely related bat coronaviruses in laboratory conditions. The strength of this neutralization decreased with evolutionary distance, indicating that immunity generated by SARS-CoV-2 exposure provides stronger protection against nearby viral relatives than distant ones. This pattern suggests a connection between viral evolutionary proximity and cross-protective immunity.
This discovery could influence pandemic preparedness strategies by identifying which emerging zoonotic threats pose the greatest spillover risks to humans. If widespread SARS-CoV-2 immunity does create barriers against related viruses establishing human infections, public health systems may need to adjust surveillance and vaccination priorities. However, the findings underscore that cross-protection is limited to closely related viruses, meaning novel or distant coronavirus variants could still pose significant threats regardless of existing population immunity.