University of Pittsburgh researchers have identified tiny molecules that show promise in preventing and treating COVID-19 and its variants. They seem to have uncovered clues to halting diseases caused by other coronaviruses, as well.

Pitt Med’s Yi Shi, with other scientists, tested those microscopic molecules—called SARS-CoV-2 nanobodies—as an inhalable mist in hamsters and discovered how much potential they offer.

Last year, Shi, assistant professor of cell biology, and his fellow researchers extracted SARS-CoV-2 antibody fragments from a llama named Wally. Those fragments were later used to prevent and treat COVID-19 in the hamsters.

In the team’s most recent research, Shi partnered with Pitt Med’s Cheng Zhang, associate professor of pharmacology and chemical biology, James Conway, professor of structural biology, and colleagues at Case Western Reserve. They studied the nanobodies to better understand how they interact with SARS-CoV-2 to stop it from infecting cells and to probe how mutations found in variants might affect nanobody interactions. The team chose eight potent neutralizing nanobodies for further examination by first confirming that several work against alpha, delta and other SARS-CoV-2 variants. The team then classified the nanobodies into groups based on their interactions with spike proteins—which act as “keys” that grant the virus entry to human cells. The research revealed three classes of interest.

One of those classes of nanobodies binds to a region on the spike protein that has persisted through several permutations of coronaviruses. This means it may neutralize SARS-CoV-2 and its variants, as well as other coronaviruses.

Shi says this work “will not only help our team select and refine nanobodies to treat and prevent COVID-19, it also may lead to a universal vaccine, preventing not just COVID-19, but SARS, MERS and other diseases caused by coronaviruses.”