You can now get a flu vaccine via a 'jet injector,' which shoots it straight into your arm without a needle

A futuristic-looking jet injector can shoot this year's flu vaccine into your arm without a needle.

Though it may look like something from a sci-fi movie, the PharmaJet Needle-free Jet Injector is inspired by vaccination guns that have been used since the 1960s, according to the US National Library of Medicine.

The first ones were powered by electricity or foot pumps and administered smallpox vaccines. They actually played a big role in eradicating the disease.

"Ultimately," the National Library of Medicine notes, "the bifurcated needle came to be preferred over the jet injector." It required only a quarter as much vaccine and was highly reliable.

But now the jet injector is back.

The US Food and Drug Administration approved the PharmaJet for flu vaccination in August 2014. 

It works by injecting the flu vaccine at pressures high enough that the very fine stream of liquid can penetrate the skin and go into the muscle. (Imagine a water gun with a stream powerful enough to enter your skin.)

You can see the injector at work in this GIF of a journalist at a local Colorado news station getting his vaccine:

He said he felt a slight pressure and heard a small pop as the PharmaJet injected the flu vaccine into his arm.

The US Centers for Disease Control and Prevention say only people aged 18-64 can get the flu vaccine via the PharmaJet injector. The primary audience is people afraid of needles, though it's not clear which type of shot is less painful. There's also a nasal spray vaccine available.

The PharmaJet shot contains three strains of the flu virus, making it "trivalent." This year's combination includes two influenza A (H1N1 and H3N2) viruses, and one influenza B virus, according to the CDC.