Shape-Shifting Vaccines Wanted for Killer Viruses
A DARPA project is focused on creating vaccines that lie dormant until a virus appears and then self-replicate to outnumber their foes.
Zika. Ebola. Dengue. Influenza. Chikungunya. These deadly viruses are crafty organisms that can mutate inside their hosts, quickly outdating any vaccine and rendering it useless.
In an effort to stay one step ahead of these formidable foes, the Defense Advanced Research Projects Agency (DARPA) recently announced a new project to develop "shape-shifting" vaccines that cannot be outsmarted.
The new DARPA project, called Intercept, was created to outpace evolving pathogens with a therapy that can adapt in real time, "shape-shifting as fast as its targets do," according to the agency.
Intercept isn't starting from zero, fortunately. The agency plans to build on existing lab-grown snippets of genetic material called TIPs - short for therapeutic interfering particles. Packaged in protein shells familiar to a person's immune system, these little guys can operate like incredibly persuasive secret agents for the body.
TIPs enter host cells in a way that's similar to viruses. However, they do not contain the genetic material designed to hi-jack a cell and force it to replicate more copies, the way viruses do. Instead, TIPs lie in wait until a virus infects a cell and at that point, begin to self-replicate and compete with the virus. TIPs quickly outnumber the virus, which comes to a screeching halt.
"Think of these TIP-filled envelopes as tiny Trojan horses," DARPA program manager Jim Gimlett said in a press release about Intercept. "But instead of containing warriors, they contain pretenders that ultimately outnumber real disease-causing viruses and interfere with their ability to replicate."
Because the TIPs are made from genetic material, they have the potential to evolve alongside the viruses, too.
TIPS aren't quite ready for deployment yet, though. DARPA still has to develop ones that can stay dormant in uninfected cells and then start replicating fast enough to outcompete viruses once infection happens. The agency also plans to create computer models for designing effective TIPs, and they need to conduct long-term studies of TIPs' co-evolution with a virus.
Early DARPA-funded studies seem promising. Engineered TIPs reduced viral loads nearly 20-fold for cells growing in culture dishes, according to the agency.
They've clearly done plenty of recon and now it's time to prepare the troops for battle. When it comes to viruses like Zika and Ebola, the only way to destroy them is from the inside.
Scientists are able to engineer biological systems to perform useful tasks for humans.