Young men may have another reason to get vaccinated against HPV. New research this month found that men infected with high-risk strains of the human papillomavirus had higher numbers of dead sperm than those who didn’t. The findings suggest that HPV can potentially worsen male fertility, the researchers say.
HPV is an extremely common sexually transmitted viral infection, and almost anyone can get it at some point in their life. But there are more than 200 types of the virus, and there are important differences between them. Some types cause no problems, while others cause unsightly or even dangerous symptoms, such as genital warts. But high-risk HPV types can persist in the body, triggering changes in infected cells that increase the risk of several different cancers. High-risk HPV infections cause almost all cases of cervical cancer in women, but also the majority of cases of penile cancer in men, and most cancers of the anus, throat, and mouth in both men and women.
Argentine scientists conducted this latest study in hopes of better understanding how high-risk HPV infections can affect men’s health. They analyzed semen samples from more than 200 men who visited the same urology clinic between 2018 and 2021. About 20% of these men tested positive for HPV, including 20 who were clearly positive for high-risk HPV infection.
Using conventional tests, the researchers initially found no major differences in sperm quality between men with and without high-risk HPV. But their more sensitive tests revealed that high-risk HPV cases tended to have a higher percentage of dead sperm than men with low-risk or uninfected HPV. Men with high-risk HPV were also more likely to have lower levels of white blood cells in their semen, as well as greater oxidative stress. The team’s findings were published this month in Frontiers in cellular and infectious microbiology.
“We concluded that HR-HPV-infected men, but not LR-HPV-infected men, have increased sperm mortality due to oxidative stress and a weakened local immune response in the urogenital tract,” Virginia Rivero, the study’s lead investigator and a professor at the National University of Córdoba in Argentina, said in a statement from Frontiers, the study’s publisher. “These findings suggest that HR-HPV-positive men may have reduced fertility.”
The results are based on a very small sample of men who may not be representative of the general population. More research will be needed to confirm whether high-risk HPV can actually harm men’s sperm quality and fertility on a population-wide basis. The researchers also plan to investigate whether having other STIs in addition to HPV can further harm men’s reproductive health.
However, given the already well-known risks of these infections, getting protection against infertility from the HPV vaccine would be just the cherry on top. The most recent HPV vaccines are designed to prevent infections caused by the most common types of warts and cancers. Currently, all children and young adults under the age of 26 in the United States are recommended to get the HPV vaccine (two or three doses depending on age), although people as young as 45 can still get it.
