(Reuters)

An experimental chewing gum that “traps” SARS-CoV-2 particles in saliva holds promise for curbing transmission of new variants of the virus, according to new data, as researchers prepare to launch the first human trial.

The gum contains copies of the ACE2 protein found on cell surfaces, which the coronavirus uses to break into cells and infect them. In test-tube experiments using saliva from individuals infected with the Delta or Omicron variants, the virus particles attached themselves to the ACE2 “receptors” in the chewing gum and the viral load fell to undetectable levels, researchers reported in Biomaterials.

In the clinical trial, COVID-19 patients will each chew four ACE2 gum tablets each day for four days.

The “viral trap” ACE2 proteins in the gum are carried within engineered lettuce cells. A second experimental chewing gum made with bean powder instead of lettuce cells not only traps SARS-CoV-2 particles in lab experiments but also influenza strains, other coronaviruses that cause common colds, and potentially other oral viruses such as human papillomavirus and herpesvirus, according to the paper.

“Because nasal transmission is negligible when compared to oral transmission… chewing ACE2 gum and swallowing ACE2 protein should minimise infection, protect COVID-19 patients and prevent transmission,” said research leader Dr Henry Daniell of the School of Dental Medicine at the University of Pennsylvania.