Study Finds COVID-19 Immunity Extends to Related Bat Coronaviruses

People who recovered from COVID-19 or were vaccinated against SARS-CoV-2 are more likely to carry immunity that also recognizes other bat coronaviruses closely related to the virus, according to a joint study by The Pirbright Institute and King’s College London. The research appears in two companion papers in PLOS Biology.

The team studied how a diverse set of bat sarbecoviruses—the coronavirus subgroup containing SARS-CoV-1 and SARS-CoV-2—interact with ACE2, the cellular receptor many coronaviruses use to enter host cells. They tested 15 representative bat coronavirus spike proteins against ACE2 receptors from 34 species, including bats, humans, livestock, rodents, and animals previously suggested as intermediate hosts.

So-called “generalist” viruses, able to use ACE2 from many different species, were concentrated almost entirely within the same evolutionary group as SARS-CoV-2, including the BANAL viruses found in Laos. Viruses from other branches, such as a newly identified UK bat coronavirus called RhGB07, whose spike structure was resolved by Swiss collaborators, showed more limited receptor use. The researchers also found that SARS-CoV-2 itself shifted its host range during the pandemic, with Omicron-lineage mutations in the receptor binding domain changing which species’ ACE2 the virus could use.

Testing blood samples from people who had recovered from COVID-19, the team found antibodies that neutralized closely related bat coronaviruses effectively, and more distant sarbecoviruses to a lesser degree. “Our findings suggest that the bat coronaviruses currently considered most likely to spill over into humans are also most likely to be recognized by existing COVID-19 immunity. While spillover risk can never be eliminated, widespread exposure to SARS-CoV-2 may have raised the barrier for related viruses to establish themselves in human populations,” said lead author Nazia Thakur. 

According to senior author Katie Doores, “These viruses showed the strongest antigenic similarity to SARS-CoV-2, meaning they were more readily recognized and neutralized by antibodies generated following COVID-19 infection. In contrast, more distantly related bat coronaviruses tended to be “specialists”, capable of using ACE2 receptors from only a limited range of hosts.”

Further work identified monoclonal antibodies recognizing a wide range of sarbecoviruses and mapped where they bind on the spike protein, highlighting conserved regions relevant to future vaccines. “One of the encouraging findings was evidence of cross-neutralization of even some of the more distantly related bat coronaviruses. This suggests that broadly protective, pan-sarbecovirus vaccines or therapeutics may be achievable,” said co-author Dalan Bailey. The researchers say studying host range, receptor usage, and immune recognition together could help identify higher-risk viruses and strengthen pandemic preparedness.