hrHPV Prevalence Rates Differ by Country

Cervical cancer rates increasing in low- and middle-income countries
honduran women in traditional garb

A research team based in Lebanon, NH, at Dartmouth-Hitchcock's Norris Cotton Cancer Center has found that the same vaccination programs that target human papillomavirus (hrHPV) strains in the USA, may not be as effective in protecting other populations of women from the disease.

Led by Gregory J. Tsongalis, Ph.D., this new study found a very different prevalence of hrHPV in the Central American country of Honduras, when compared to the USA.

This is important news since a majority of cervical cancers are caused by persistent infection with hrHPV.

"After testing 2,645 women from multiple locations in Honduras for types of hrHPV and finding the prevalence of virus types to be quite different from those in the U.S., we asked what vaccine would be the most efficacious for the local situation, and which hrHPV types are most commonly found in cervical cancer tissues from Honduran women," said Dr. Tsongalis, in a June 4, 2020, press statement.

"The bivalent vaccine against two HPV types and the quadrivalent vaccine against four HPV types would only protect approximately half of women infected with this virus in Honduras.” 

“The most expensive vaccine would protect the majority of women.”

“However many vaccination programs in low- and middle-income countries use the less costly vaccine, and these vaccines are not providing adequate protection."

This research team's next steps are to continue to study the prevalence of hrHPV in Honduran women, as well as to do hrHPV typing on cervical tumors from other non-U.S. locations to determine which viral types are present in the cervical tumor tissue. 

"We are also investigating opportunities to study the use of the vaccine as a therapeutic," notes Dr. Tsongalis.

According to the Pan American Health Organization (PAHO), the Human Papillomavirus (HPV) is a common, sexually transmitted virus. 

There are more than 100 HPV types, and each type is identified by a number. HPV types 16 and 18 are together responsible for approximately 70% of cervical cancer cases globally.

When not vaccinated, most people will be infected with HPV at some point in their lifetime.

Three highly effective and safe vaccines are licensed around the world for preventing infection against high-risk HPV types: bivalent, quadrivalent, and nonavalent.

The quadrivalent and nonavalent vaccines are also highly efficacious in preventing genital and anal warts. 

The PAHO recommends that all countries proceed with the nationwide introduction of HPV vaccination.

In the USA, the Gardasil 9 vaccine is most ofter administered. 

Note:  Gregory Tsongalis, Ph.D., HCLD, CC, is a Professor and Vice-Chair of Research in the Department of Pathology and Laboratory Medicine at Dartmouth's Geisel School of Medicine, as well as Director of Clinical Genomics and Advanced Technology and member of the Cancer Biology and Therapeutics Research Program at Dartmouth's and Dartmouth-Hitchcock's Norris Cotton Cancer Center.

Norris Cotton Cancer Center, located on the campus of Dartmouth-Hitchcock Medical Center (DHMC), combines advanced cancer research at Dartmouth College's Geisel School of Medicine in Hanover, NH with the highest level of high-quality, innovative, personalized, and compassionate patient-centered cancer care at DHMC, as well as at regional, multi-disciplinary locations and partner hospitals throughout NH and VT.

HPV vaccine news published by Vax Before Cancer.