DARPA is investigating self-mutating vaccines to take down viruses

Alan Martin April 11, 2016

Viruses, by their very nature, are really tricky to deal with. We find a solution, they evolve, and suddenly our solution no longer works. Flu is a typical example of this, which is why the vaccine is refreshed each year at great expense.

DARPA is investigating self-mutating vaccines to take down viruses

But flu is among the least of our viral problems; Zika, Ebola and Dengue are far more of a risk.

How do you begin to deal with viruses that mutate quicker than we can provide vaccines or antivirals? DARPA, the US

Defense Advanced Research Projects Agency, thinks the solution may be playing the enemy at its own game, and making vaccines that reproduce and evolve faster than the viruses they target. hiv_infected_t_cell

The plan is to use therapeutic interfering particles (TIPs), which are thin sections of DNA within protein shells that will enter cells with viruses, and compete for the host cell. By design, the TIPs will produce a lot faster than the viruses they’re up against, reducing the effectiveness of the viruses by watering them down.

“You can think of these TIP-filled envelopes as tiny Trojan horses, but instead of containing warriors they contain pretenders that ultimately outnumber real disease-causing viruses and interfere with their ability to replicate,” explained Jim Gimlett, DARPA’s programme manager. Better still, they should also mutate and diversify over time as the viruses themselves do. “Once we develop a TIP that works for a given virus, we expect it to generate a steady stream of variants so there will always be a population of TIPs with the right genetic stuff to disrupt any new strains of that virus that may arise.”

However, if TIPs are themselves mimicking the mechanics of viruses, what’s to stop them making an individual poorly? DARPA claims this isn’t possible, because TIPs lack the genes to independently hijack a host cell’s genetic machinery.

We’re years away from this being a feasible solution in humans but early results are encouraging, with engineered TIPs reducing viral loads in cultured cells around 20-fold. The next step will be animal models, and it’s entirely possible the whole idea will fall down there, long before it even enters a first-in-man study.

If it doesn’t though, then the solution to previously terrifying viruses might nearly be within our grasp.

Images: NIAID used under Creative Commons