: It clarifies the fundamental differences between the two, noting that while both can cause similar symptoms, they require entirely different treatments—for instance, antibiotics are effective against bacteria but useless against viruses.

: Beyond viruses, the "nasties" in town include pathogenic bacteria, fungi, and other microbes that interact in "nested, dynamically complex relationships". Viruses: Impact on Science and Society - PMC

: Not all microbes are harmful. Many viruses and bacteria are essential to life, such as probiotics in the gut or bacteriophages (viruses that kill harmful bacteria).