Common wisdom is overturned as researchers show anti-bacterial drugs can also knock viruses for six.

Everybody knows antibiotics don’t work on viruses, right? Not, it turns out, if you’re a female mouse with a nasty case of genital herpes, in which case a well-timed dose of antibiotic might be just the thing, according to new researchpublished in the journal Nature Microbiology.

The researchers, led by Akiko Iwasaki from the Department of Immunobiology at Yale University in New Haven, US, infected mice with the herpes simplex virus – no trifling matter in rodents. The virus migrates from the vagina to the spinal cord resulting in hind limb paralysis, hair loss and, in some cases, death.

However, mice that were pre-treated with the antibiotic neomycin, used in humans to treat ear and skin infection and to sterilise the bowel before gut surgery, were largely spared this fate. They displayed, write the authors, “little to no disease pathology”.

How could antibiotics, which the received wisdom says are only effective against bacteria, possibly kill viruses?