It’s the dog days of summer. You bite down on a plump, chilled orange. Citrus juice explodes in your mouth in a refreshing, tingling burst. Ahh.

And congratulations—you’ve just been vaccinated for the latest virus.

That’s one of the goals of molecular farming, a vision to have plants synthesize medications and vaccines. Using genetic engineering and synthetic biology, scientists can introduce brand new biochemical pathways into plant cells—or even whole plants—essentially turning them into single-use bioreactors.