The virus that causes COVID-19 is part of a family that includes strains of the common cold.
Now, researchers at Northern Arizona University and TGen North say the antibodies that fight such non-COVID coronaviruses might affect the body's response to the pandemic virus as well.
"We have some evidence to suggest that when we get infected with the pandemic virus, these antibodies get recruited into that response," said senior author John Altin, an assistant professor in TGen North's pathogen and microbiome division.
The research appears in the journal Cell Reports Medicine.
It's too soon to tell how these antibodies affect resistance to COVID-19, if at all.
But in other viruses like influenza, antibodies from past strains can help battle newer mutations. So it's possible common cold antibodies could help researchers develop broader vaccines or treatments for the pandemic.
Altin thinks that's a distinct possibility. But he also recognizes the limitations of his work at this early stage, and allows that the preexisting antibodies might be nothing more than a distraction.
"Therefore, they have a head start over other antibodies, but when they get pulled into the response against the coronavirus, they don't really do a good job neutralizing it. So we're trying to distinguish between those two possibilities."
But there's also reason to hope holdover antibodies might be able to grapple with coronaviruses.
Using epitope resolved analysis, a technique that focuses on protein fragments instead of whole proteins, Altin and his colleagues drilled down to regions in the coronaviruses' namesake spike proteins that remain largely unchanged between the common cold coronaviruses and SARS-CoV-2, the pandemic virus.
If coronavirus mutations tend not to alter those areas, perhaps because they are difficult to change, then they could offer an Achilles heel for vaccines and treatments to target.
"If that's the case, and if these are protective responses, then they become really good candidates for what we would call the broadly neutralizing response," said Altin.
