A new study has revealed that an innovative chewing gum may be effective at reducing Covid transmission, providing a new weapon for curbing the spread of the disease.
A collaborative endeavour between researchers from the University of Pennsylvania, The Wistar Institute, and Fraunhofer USA has determined that a novel chewing gum containing a plant-grown protein can trap the SARS-CoV-2 virus, reducing viral load in saliva and lowering Covid transmission.
The findings of their study are published in the journal Molecular Therapy and may help devise an effective new weapon for battling the pandemic.
Henry Daniell, the leader of the study from the University of Pennsylvania’s School of Dental Medicine, said: “SARS-CoV-2 replicates in the salivary glands, and we know that when someone who is infected sneezes, coughs or speaks some of that virus can be expelled and reach others. This gum offers an opportunity to neutralise the virus in the saliva, giving us a simple way to possibly cut down on a source of Covid transmission.”
Reducing Covid transmission
COVID-19 vaccinations have drastically helped to reduce hospitalisations and deaths from the disease; however, they haven’t eradicated Covid transmission, as even those who are fully vaccinated can become infected with the disease. Furthermore, recent investigations have found that those who are fully vaccinated can carry similar viral loads to those who are unvaccinated.
Daniell had been researching the angiotensin-converting enzyme 2 (ACE2) protein long before the pandemic as a possible way of treating hypertension. His team grew this protein and many others that may have therapeutic potential using a patented plant-based production system. This work turned out to be extremely beneficial in terms of the COVID-19 pandemic, as the receptor for ACE2 on human cells is known to bind to the SARS-CoV-2 spike protein, with injections of ACE2 found to reduce viral load in people with severe infections.
Additionally, a different research project involved developing a chewing gum infused with plant-grown proteins to disrupt dental plaque, which led the team to investigate whether a gum laced with plant-grown ACE2 proteins can neutralise SARS-CoV-2 in the oral cavity. To examine this potential, the team collaborated with Ronald Collman at Penn Medicine, whose team had been collecting blood, nasal swabs, saliva, and other biospecimens from COVID-19 patients since the start of the pandemic.
Collman, a virologist and pulmonary and critical care doctor, said: “Henry contacted me and asked if we had samples to test his approach, what kind of samples would be appropriate to test, and whether we could internally validate the level of SARS-CoV-2 virus in the saliva samples. That led to a cross-school collaboration building on our microbiome studies.”
Chewing gum performance
In order to investigate the potential of the chewing gum, the researchers grew ACE2 in plants, paired with another compound that allows the protein to pass mucosal barriers and facilitates binding, subsequently incorporating the resulting plant material into cinnamon-flavoured gum tablets. Next, the team incubated samples from nasopharyngeal swabs from Covid-positive patients with the gum, demonstrating that the ACE2 present could neutralise SARS-CoV-2 viruses.
Additionally, the team performed further investigations where they modified viruses that are less pathogenic than SARS-CoV-2 to express the SARS-CoV-2 spike protein. This enabled the team to demonstrate that the gum largely prevented Covid transmission into the cells, either by blocking the ACE2 receptor or binding directly to the spike protein.
Finally, the team exposed COVID-19 saliva samples to the gum, identifying that the levels of viral RNA dropped to near undetectable levels. The team are now working to obtain permission to conduct clinical trials to determine if the chewing gum is safe and effective when tested in people infected with SARS-CoV-2.
Collman said: “Henry’s approach of making the proteins in plants and using them orally is inexpensive, hopefully scalable; it really is clever.”
Although the research is still in the early stages, if clinical trials demonstrate that the gum is safe and effective, it could be administered to patients whose infection status is unknown or for dental check-ups when masks must be removed, reducing the chances of Covid transmission.
Daniell commented: “We are already using masks and other physical barriers to reduce the chance of Covid transmission. This gum could be used as an additional tool in that fight.”
