1 in 5 people have genital herpes says latest WHO report
December 12, 2024
Updated World Health Organization (WHO) estimates show 1 in 5 people aged under 50 have genital herpes.
The new report, which is based on data from 2020, confirms the most common cause of genital herpes remains from the type 2 version of the herpes simplex virus (HSV-2).
There have been increases in genital herpes from HSV type 1, though this is coming from a much lower base.
HSV-1 is more commonly associated with oral infection and is the cause of common oral cold sores. Two in three people globally are estimated to have the disease.
While both variants can cause genital herpes, the vast majority of cases are caused by HSV-2.
Many people living with herpes never experience symptoms. In some cases, genital ulcer disease may develop, usually appearing as small, sometimes red blisters around the genitals.
These are different to genital warts, which usually appear as small, raised bumps and are caused by the human papillomavirus (HPV).
What does the new data show on herpes infections?
The report published in the journal Sexually Transmitted Infections reviewed data in 15–49-year-olds around the world
According to the report, HSV-2 is still the predominant cause of genital sores globally.
More than 200 million people had a case of genital ulcers in 2020 — 16.7 million from HSV-1, and 187.9 million from HSV-2.
On top of this, hundreds of millions of people continued to contract or live with the infection.
25.6 million had a newly acquired HSV-2 infection in 2020. 519.5 million were already infected.
16.8 million had a newly acquired HSV-1 genital infection in 2020, adding to 376.2 million already with the disease.
Herpes is rarely lethal, so why is action needed?
Whether transmitted sexually or orally, herpes is a disease that people live with over their lifetime. There is no cure for herpes.
It's for these reasons that finding a vaccine is important, the report's lead researcher Laith J. Abu Raddad, Cornell University, US, said.
"It's something that's annoying to a lot of people that live with symptomatic ulcers that affect their sexual relationships, [and] impact their psychology, and so on,” he told DW.
Recent analyses put the global economic cost of genital herpes at $35 billion every year. This burden is mostly shouldered in the Americas and Western Pacific regions, with costs tied up in direct medical interventions.
Symptomatic HSV-2 infection is also associated with an increased risk of HIV transmission. While research into this connection is ongoing, earlier investigations found a tripling in the risk of HIV infection among those with HSV-2.
A 2020 report found that around 30% of new HIV infections could be attributed to type 2 genital herpes.
Abu Raddad pointed to interventions that can help reduce the spread of infection, including the use of condoms, antivirals to reduce viral replication and sexual abstinence.
Relying on those measures to reduce transmission is not always realistic though.
"If we develop a vaccine, people will take it at a young age and it will protect them. That would be a substantial improvement in society," he said.
Herpes vaccines would stop infections spreading
There are still no licensed vaccines to prevent herpes infection, although pharmaceutical companies are testing several vaccines in clinical trials.
MRNA vaccine pioneers BioNTech and Moderna are both trialing potential genital herpes treatment options. Their medications include prophylactics (meaning they prevent infection) and therapeutics that reduce severity and viral load.
Another company, GSK, completed a vaccine trial in September 2024, but the vaccine did not prove to be effective.
"It has been a challenging field for sure, " said Sami Gottlieb, a medical officer in the WHO's Department of Sexual and Reproductive Health and Research in Geneva, Switzerland. Gottlieb works on STI vaccine programs and contributed to the latest WHO report.
Her priority has been increasing disease awareness and destigmatisation, given so many people have herpes infections around the world.
She also points to the importance of lessening the burden on regions disproportionately affected by herpes, such as sub-Saharan Africa and Latin America.
"The hope globally is a prophylactic vaccine that would prevent infection, similar to how we think about the HPV vaccine that's currently being rolled out could be given to adolescents or young adults," Gottlieb said.
"There's a disproportionate burden, especially in the African region, for general HSV-2 infection, that's why things like HSV vaccine development are not just important for decreasing the global health burden but also for equity."
Edited by: Fred Schwaller
Primary source:
Estimated global and regional incidence and prevalence of herpes simplex virus infections and genital ulcer disease in 2020: mathematical modelling analyses. Published by Manale Harfouche et al. in Sexually Transmitted Infections. http://dx.doi.org/10.1136/sextrans-2024-056307
Estimated economic burden of genital herpes and HIV attributable to herpes simplex virus type 2 infections in 90 low- and middle-income countries: A modeling study. Published by Sachin Silva, Houssein H Ayoub, Christine Johnston, Rifat Atun, Laith J Abu-Raddad. in PLOS Medcine. https://doi.org/10.1371/journal.pmed.1003938
Estimated global and regional economic burden of genital herpes simplex virus infection among 15–49 year-olds in 2016. Published by Nathorn Chaiyakunapruk et al. in BMC Global and Public Health. https://doi.org/10.1186/s44263-024-00053-6.
Global and regional estimates of the contribution of herpes simplex virus type 2 infection to HIV incidence: a population attributable fraction analysis using published epidemiological data. Published by Katharine J Looker et al. in The Lancet Infectious Diseases. https://doi.org/10.1016/S1473-3099(19)30470-0.