Single Dose of HPV Vaccine Is Highly Effective: Study

A new study shows that one dose of a vaccine that can prevent the virus that leads to most cases of cervical cancer may be as effective as the usual two or three doses. 

The findings could have a significant impact on cutting the rate of cervical cancer worldwide, because a single dose would simplify the vaccination process and cost less. Cervical cancer is the fourth most common type of cancer among women, killing an estimated 342,000 worldwide in 2020. 

The vaccine prevents transmission of cancer-causing strains of the sexually transmitted disease called human papillomavirus, or HPV. The first HPV vaccine was approved in the U.S. in 2006, and the CDC currently recommends two or three doses, depending on a person's age.

The new findings were presented at the end of April during the 35th International Papillomavirus Conference in Washington, DC. The study included 2,275 people in Kenya who ranged in age from 15 to 20 years old. They were randomly assigned to receive one of three treatments: a single-dose vaccine that targets two HPV strains, a single-dose HPV vaccine that targets nine strains, or a control vaccine. Participants were regularly tested for 3 years. The two-strain vaccine was 98% effective, and the nine-strain vaccine was 96% effective, the researchers reported.

In December, the World Health Organization reduced its recommended number of HPV vaccine doses to one, noting at the time that just 15% of girls worldwide got the vaccine in 2021.

"Following the WHO recommendation in support of a one-dose regimen for HPV vaccine could help make the vaccine more accessible to women and girls around the world by lowering costs, alleviating pressure on supply, and making the vaccine easier to deliver," Peter Dull, MD, deputy director for clinical vaccine development at the Bill & Melinda Gates Foundation, which funded the research, said in a statement.

At least 24 countries have already adopted the single-dose approach, The New York Times reported. More results from the research are expected in 2025, including a formal scientific test of multi-dose vs. single-dose protection, the newspaper said. 

Sources

Kenya Medical Research Institute: "Single-Dose HPV Vaccine Highly Efficacious over three years, New Study Finds."

Massachusetts General Hospital: "Research Spotlight: Single Dose of HPV is Highly Efficacious in Protecting Young Women."

World Health Organization: "WHO updates recommendations on HPV vaccination schedule."

The New York Times: "One Dose of HPV Vaccine Prevents Infection for at Least Three Years."

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Cite this: Single Dose of HPV Vaccine Is Highly Effective: Study - Medscape - May 03, 2023.