Nearly 846 million people ages 15 to 49—or around one in five adults in this age group worldwide—are living with genital herpes, according to the World Health Organization. The new analysis also estimates that some 42 million people acquired genital herpes in 2020. While herpes simplex virus (HSV) infection often has no symptoms, it can cause recurring painful ulcers. HSV-1 usually spreads via saliva and causes sores on the mouth, while HSV-2 is typically sexually transmitted and causes genital or anal lesions; however, both types can cause genital herpes. Herpes sores usually heal within a couple of weeks, but HSV lies dormant in nerve cells and can reactivate. People living with HIV are more likely to carry HSV-2 and are prone to more frequent and severe outbreaks. What’s more, having genital herpes facilitates both HIV acquisition and transmission. Antiviral medications can reduce the severity of herpes outbreaks, but they don’t eliminate the virus. The study authors urge more investment to develop herpes vaccines and better therapies.