The experiment will first involve storing a virus in a vacuum and then cooling it to its quantum mechanical ground state in a microcavity. Zapping the virus with a laser then leaves it in a superposition of the ground state and an excited one.
This works only if the virus behaves like a dielectric, can survive the vacuum and appears transparent to laser light, which would otherwise rip it apart.
As luck would have it, Romero-Isart and co say that several viruses fit the bill. The common flu virus is known to be able to survive in a vacuum, seems to have the required dielectric properties and may well be transparent to a careful choice of laser light. The tobacco mosaic virus, to all intents and purposes a dielectric rod, looks like another good candidate.