Traditionally, vaccines take the form of viral proteins, killed viral samples or weakened live viruses. While this approach has been successful for illnesses like the flu or measles, the World Health Organization describes vaccines for diseases like HIV-1 and malaria as “in the pipeline,” meaning that they are not yet fully effective.

Researchers have turned nanoparticles into a new tool in vaccine design to help protect against these deadly illnesses.

In the past, scientists have used unbound viral sugars or proteins as vaccines when using live or weakened viruses was not possible. These lone macromolecules were not enough to provoke strong immune recognition of viral invaders.

Viral proteins and sugars can be attached directly to surface nanoparticles to facilitate activation of the host immune system.

Because multiple polysaccharides and proteins can be arranged on the surface of the nanoparticle, many interactions with immune cells can occur as the nanoparticle nears the cell. This is a much more realistic scenario of what may happen when immune cells recognize new viruses.

According to a 2013 paper in Frontiers in Cellular and Infection Microbiology by Gregory et al., nanoparticles are usually less than 1000nm, or 0.000039 inches, in diameter.

Currently, nanomaterials such as liposomes (small bubbles of lipids with a watery interior), polymers of sugars or proteins and materials like gold and silica are being explored.

Antigens, viral molecules that can be recognized by the immune system, can either be coated onto the nanoparticle or packaged inside to protect these molecules from degradation within the body.

One of the major challenges in vaccine design is getting a virus, or in this case, nanoparticles, into the region of the lymph nodes where they can interact with immune cells and so that the body will recognize the invader in the future.

According to a recent Science article by John Wilson, many nanoparticles are trapped before they can reach the B cell zone and trigger antibody production to train the immune system for future invasions. This prevents the nanoparticles from triggering full immunity.

Researchers led by Talar Tokatlian from the Koch Center for Integrative Cancer Research at MIT have discovered that coating nanoparticles with sugars called glycans can vastly improve their recognition by the immune system.

Tokatlian and the other researchers involved in the project demonstrated that nanoparticles accumulate in the necessary region of lymph tissues much more quickly and remain longer than free viral proteins.

The team then discovered that glycosylation of the nanoparticle surface allows for the creation of a better vaccine.

Glycosylation is a common biological process in which carbohydrate sugars are attached to proteins.

The group from MIT glycosylated their nanoparticles to promote interaction with Mannose-Binding Lectin (MBL), a protein which interacts with various sugars to increase their recognition by the immune system.

This result suggests that other nanoparticle vaccines could become more effective if glycosylated.

According to Gregory et al., select nanoparticle vaccines have already entered clinical trials in humans.

As researchers and clinicians seek to optimize these vaccines, current research into nanoparticle delivery may make nanoparticle vaccines more efficient and allow them to reach patients faster.

With this work, scientists are hoping to better and more readily combat different viral outbreaks that are affecting the world.

Scientists and researchers also hope that this new method will allow the creation of new vaccines for different and more deadly viruses, including Ebola.

Although these tests require years of more work they will bring us closer to a healthier future.