Human papillomavirus (HPV) is a widespread viral infection, affecting nearly 80 million Americans, or about one in four people in the United States. This common virus often raises questions about its long-term effects and the possibility of a definitive cure. Understanding the current scientific landscape surrounding HPV involves exploring its nature, existing treatments for its manifestations, and ongoing research efforts to eradicate the virus from the body.
The Nature of HPV and Viral Persistence
HPV is a virus that infects epithelial cells, found on skin and mucous membranes like those in the oral or genital areas. It typically enters through microabrasions, infecting basal keratinocytes. The body’s immune system usually clears HPV infections within one to two years, often without symptoms.
However, some HPV infections, particularly high-risk types, can persist. This occurs when the immune system does not effectively eliminate the virus, potentially leading to cellular changes that may progress to cancer over years or decades. HPV has evolved mechanisms to evade immune detection. While “viral clearance” or “remission” means the body has eliminated the virus, a “cure” would involve a medical intervention to eradicate it.
Treating HPV-Related Conditions
While no medical treatment can eliminate the HPV virus itself, therapies manage and remove conditions it causes, such as warts and precancerous lesions. Genital warts, often caused by HPV types 6 and 11, are treated with patient-applied or doctor-administered methods. Patient-applied options include imiquimod cream, which boosts the immune system, and podofilox solution or gel, which stops cell division.
For doctor-applied treatments, cryotherapy uses liquid nitrogen to freeze and remove warts. Trichloroacetic acid or dichloroacetic acid chemically burn them off. Surgical removal methods like shaving excision, laser therapy, or electrosurgery are also employed.
For precancerous cervical cell changes, often detected through Pap tests, procedures like Loop Electrosurgical Excision Procedure (LEEP) use an electrified wire loop to remove abnormal tissue. Other methods include cryosurgery, laser surgery, or cold knife cone biopsy. All are aimed at removing affected tissue to prevent cancer progression.
The Search for a Viral Cure
The search for an HPV cure focuses on therapies that could directly eliminate the virus, moving beyond symptom management. Therapeutic HPV vaccines are a promising research area, designed to boost the body’s immune response against existing high-risk HPV strains or precancerous cells. Over 20 therapeutic HPV vaccine candidates are in various development stages, with several undergoing clinical trials.
One example is the Vvax001 vaccine, which targets HPV16 and showed regression in high-grade precancerous cervical lesions in a phase II clinical trial. This vaccine uses a modified virus to produce HPV proteins and trigger an immune response. Another approach involves a vaginal insert being tested in a clinical trial, aiming to eliminate abnormal cells and clear the HPV infection without surgery.
Preventing HPV and Early Detection
Preventing HPV infection is achieved through vaccination, which protects against high-risk types associated with cancer and common types causing genital warts. The HPV vaccine is recommended for individuals aged 9 to 26, ideally before sexual activity, and can be considered for adults up to age 45. Individuals under 15 receive two doses, while those 15 and older receive three doses over six months.
Beyond vaccination, regular screening helps manage HPV’s public health impact by detecting precancerous changes early. Pap tests collect cervical cells to check for abnormalities, while HPV tests look for the DNA of high-risk HPV types.
For women aged 21-29, a Pap test every three years is recommended. For those aged 30-65, co-testing (both Pap and HPV tests) every five years or an HPV test alone every five years are common recommendations. These screenings allow for timely intervention if precancerous cells are detected, preventing their progression to cancer.