From childhood immunizations to COVID-19, multiple, staggered vaccine doses are key to providing full protection against pathogens. But can the doses be delivered all at once and lie dormant until the right time? That is the question at the heart of new research from the Massachusetts Institute of Technology.
In the study, details of which were published in Science Advances, the researchers describe the analysis of a release mechanism from biodegradable core-shell microparticles. By understanding how and when the particles degrade to release their payloads, the team pointed to the potential to create single-shot vaccines that both prime and boost the immune system.
“We believe these core shell particles have the potential to create a safe, single-injection, self-boosting vaccine in which a cocktail of particles with different release times can be created by changing the composition. Such a single injection approach has the potential to not only improve patient compliance but also increase cellular and humoral immune responses to the vaccine,” Robert Langer, one of the senior authors of the paper, said in a statement.
In the study, the researchers showed that PLGA, the biocompatible polymer used to make the particles, is gradually cleaved by water. When enough polymers have broken down, the lid of the particle becomes porous and soon thereafter breaks to release the payload.
How long it takes for pores to develop depends on the polymer. That finding suggests it may be possible to develop vaccines and other pharmacological products that release their payloads across a series of time points.
“If you want the particle to release after six months for a certain application, we use the corresponding polymer, or if we want it to release after two days, we use another polymer. A broad range of applications can benefit from this observation,” Morteza Sarmadi, lead author on the paper, said in a statement.