"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," said Dr. Nazia Thakur, a Pirbright postdoctoral scientist and lead author of the study. "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."

COVID-19 antibodies neutralize related bat viruses

To understand what this means for human health, the scientists examined blood samples from people who had recovered from COVID-19. Antibodies in those samples successfully neutralized a range of closely related bat coronaviruses. The researchers also detected lower levels of neutralization against more distant bat sarbecoviruses, hinting at some degree of broader protection.

"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," explained Katie Doores, professor of viral immunology at King's College London. "In contrast, more distantly related bat coronaviruses tended to be 'specialists,' capable of using ACE2 receptors from only a limited range of hosts."

Antigenic similarity, in plain terms, means the viruses share enough molecular features on their surfaces that antibodies trained against one virus can recognize the other.

Shared spike regions could guide next-generation vaccines

Further experiments at King's College London and Pirbright identified several monoclonal antibodies — laboratory-made copies of single immune proteins — capable of recognizing a diverse range of sarbecoviruses. The second companion article mapped exactly where these antibodies bind, pinpointing conserved regions of the coronavirus spike protein, meaning sections that stay largely the same across many different viruses.

Those conserved regions offer important clues for designing next-generation vaccines and treatments intended to work against whole families of viruses rather than a single strain.

"One of the encouraging findings was evidence of cross-neutralization of even some of the more distantly related bat coronaviruses," said Dr. Dalan Bailey, head of Pirbright's Viral Glycoproteins group. "This suggests that broadly protective, pan-sarbecovirus vaccines or therapeutics may be achievable."

Why it matters

The work's key contribution is methodological as much as it is medical. By studying virus host range, receptor usage and immune recognition together rather than in isolation, the researchers identified characteristics that distinguish higher-risk viruses from those less likely to spill over into humans. That framework could sharpen global pandemic preparedness efforts.

Some caution is warranted. The neutralization experiments used blood samples from COVID-19 survivors, and protection measured in a lab dish does not automatically translate into protection from real-world infection. How long this cross-immunity lasts, and how it holds up against viruses that evolve further, remains open questions. Still, the findings suggest that humanity's painful encounter with SARS-CoV-2 may have purchased at least a partial shield against some of its closest viral cousins lurking in bats.

Publication details:

Nazia Thakur et al, Breadth of ACE2 receptor usage predicts host range and antigenic relatedness across bat sarbecoviruses, PLOS Biology (2026). DOI: 10.1371/journal.pbio.3003944

Ayush Upadhyay et al, Targeting of conserved spike epitopes enables broad antibody neutralisation of diverse bat sarbecoviruses, PLOS Biology (2026). DOI: 10.1371/journal.pbio.3003882