In a new study in the Cell Press, researchers successfully demonstrated a phage-based inhaled vaccine for respiratory disease produces a viable immune response.

The study shows a phage-based vaccine inhalation system producing strong antibody responses in mice and primates without causing pulmonary damage. The results suggest that one day a healthy and reliable system could be used for breathing in vaccinations and even treatments.

As an alternative to the traditional needle, spraying and inhaling vaccines may be an effective way to help society avoid the economic and practical constraints of the needle-and-syringe-delivered vaccine. Their key benefits for respiratory diseases like COVID-19 are to avoid the bacteria from developing in the nose, which can spread to the rest of the body.

Senior study author Wadih Arap of Rutgers Cancer Institute of New Jersey explained, "This translational strategy potentially enables more effective delivery of therapeutics or vaccines while reducing the chance of toxic side effects. In ongoing research, we hope that this work will play a crucial role in the development of targeted vaccines and treatments to block the spread of respiratory infectious diseases, possibly for the current COVID-19 pandemic, especially in the setting of underserved populations."

Airborne pathogens such as TB, influenza, Ebola, and COVID-19 could be covered by pulmonary transmission. But this method was not generally accepted partially because of the still unknown existence of underlying physiological mechanisms.

According to the scientists, the latest method for lung delivery is secure and efficient and has specific benefits for the production of airborne pathogen vaccines and therapies. Phage particles develop extremely efficient and long-term immune responses, with no toxic adverse effects. As they do not replicate inside eukaryotic cells, their use is usually considered healthier in comparison with other conventional viral vaccine strategies. Phage particles have in fact been used for decades as antibiotics and vaccine carriers against multidrug-resistant bacteria.

Practically, phages are highly stable, and their broad production is extremely cost-effective compared to conventional approaches for the production of vaccines in harsh environmental circumstances. In addition, the current pulmonary system does not have bulky, strict or costly cold chain criteria for field applications in the developing world, as opposed to traditional peptide-based vaccines that are mostly in-activated. "In addition, phage particles are versatile and can be genetically engineered by standard molecular biology technology," says Arap.

Unlike some of the latest COVID-19 vaccines which have reached or are nearing public readiness, the new lung delivery system has no cumbersome, stringent, or expensive cold-chain requirements for field applications in the developing world.

Cover photo: "A healthcare practitioner administering the H1N1 live attenuated intranasal vaccine (LAIV) to a female recipient. Original image sourced from US Government department: Public Health Image Library, Centers for Disease Control and Prevention. Under US law this image is copyright free, please credit the government department whenever you can”."by Centers for Disease Control and Prevention is marked with CC0 1.0