Nasal spray vaccines accomplish just that. A technique known as thin-film freeze-drying, or T.F.F.D., allows scientists to transform liquid vaccines into powders. Trehalose, a derivative of sucrose, or table sugar, is often added, which prevents the formation of toxic structures by creating organic glass “orbs” around proteins, maintaining the biological activities that elicit the immune response. In T.F.F.D., liquid vaccines are dropped on an ultracool surface, causing materials to freeze. Pressure is then reduced and low heat is applied so that the frozen water changes directly from solid to gas. The result? Powdered vaccines that “revive” with a quick spray in the nose.
Medical research is currently well underway, spearheaded by Seongkyu Yoon, a professor of chemical engineering at the University of Massachusetts Lowell, who was recently granted $930,000 for the development of freeze-dried mRNA vaccines suitable for large-scale production. He explains that the T.F.F.D. process makes vaccines “more stable” and able to “extend their shelf life, as well as make them easier to transport, store and use.” This eliminates the need for cold-chain systems, and perhaps even medical workers, which, together, account for 72 percent of worldwide transportation costs, the equivalent of more than $1.2 billion. With lowered costs, vaccines can reach developing countries that were previously unable to afford the massive costs of outreach and transportation.
Intranasal vaccines have also proven more effective than traditional injections against pulmonary diseases like Influenza B and Covid-19. As Akiko Iwasaki, a professor of immunobiology at the Yale School of Medicine, explained in an interview, “the beauty of the local mucosal vaccine is that not only does it provide protection acutely, but also it’s a long-lasting immunity.” More important, dry vaccines create the potential for a pain-free alternative, which, as Dr. Iwasaki goes on to add, will likely “increase the number of people who want to vaccinate themselves,” especially for the 20 percent of the world’s population “afraid to take the needle.”
With over a dozen nasal vaccines in development worldwide, some now in Phase 3 trials, vaccines can finally be made available to all countries, not just a select few. Their superior efficacy and low transportation and outreach costs offer great potential in controlling the pandemic, especially as new, more lethal variants emerge. These pain-free nasal vaccines could help us get back to pre-Covid normal.
Works Cited
AboulFotouh, Khaled, et al. “Next-Generation Covid-19 Vaccines Should Take Efficiency of Distribution into Consideration.” AAPS PharmSciTech, 9 April 2021.
Cicco, Nancy. “UMass Lowell Is Working to Freeze-Dry Covid Vaccines.” UMass Lowell, 20 Jan. 2022.
Forman, Robert. “Nasal Vaccination May Protect Against Respiratory Viruses Better Than Injected Vaccines.” Yale School of Medicine, 21 Dec. 2021.
Griffiths, Ulla. “Costs of Delivering Covid-19 Vaccine in 92 AMC Countries.” World Health Organization, 8 Feb. 2021.
Love, Ashley S., and Robert J. Love. “Considering Needle Phobia Among Adult Patients During Mass Covid-19 Vaccinations.” Journal of Primary Care & Community Health, 3 April 2021.
Mandavilli, Apoorva. “The Covid Vaccine We Need Now May Not Be a Shot.” The New York Times, 2 Feb. 2022.