A recent study by investigators from Yale University’s School of Medicine has discovered that rhinovirus, the most common cause of colds, can help protect against SARS-CoV-2 viruses and fight COVID-19.
The results of the study were published in Journal of Experimental Medicine.
“There appears to be a viral sweet spot in early COVID-19, where the virus replicates exponentially before triggering a strong defense response,” Ellen Foxman, senior author of the study and an assistant professor of laboratory medicine and immunobiology at, said Yale School of Medicine. “But it all depends on the timing.”
The team behind the study has done previous work showing that cold viruses can protect against the flu, so they set out to investigate whether they could also help with COVID-1
For this study, the team infected the laboratory with cultured tissues from human airways with SARS-CoV-2 virus and then exposed them to a rhinovirus.
Results from the study showed that the viral load in the infected tissue doubled approximately every 6 hours, but the replication of the virus stopped completely in the tissue exposed to rhinovirus.
In addition, the investigators examined nasal inoculum samples from COVID-19-infected patients and saw that there was rapid growth of the virus in the first few days before the immune system’s defenses began to kick in, just as they saw in the laboratory.
“These results, and our findings in longitudinal patient samples, support the concept that the innate immune system is dynamic, with the innate immune system rapidly changing in response to current and recent viral infections,” the authors wrote. “Our findings also show that ISG-mediated defense can greatly limit SARS-CoV-2 replication under certain conditions and force further studies of the role of heterologous innate immunity to protection against SARS-CoV-2 and other respiratory viruses.