一項新的研究顯示，可以預防導致大多數子宮頸癌病例的病毒的一劑疫苗可能與通常的兩劑或三劑疫苗一樣有效。

這些發現可能對降低全球子宮頸癌的發病率產生重大影響，因為單劑疫苗可以簡化疫苗接種過程並降低成本。 子宮頸癌是女性中第四大最常見的癌症類型，2020 年全球估計有 342,000 人死於孑宮頸癌。

該疫苗可防止稱為人乳突狀瘤病毒或 HPV 的性傳播疾病的致癌病毒株的傳播。 第一種 HPV 疫苗於 2006 年在美國獲得批准，CDC 目前建議接種兩劑或三劑，具體取決於一個人的年齡。

此一新發現於 4 月底在華盛頓特區舉行的第 35 屆國際乳突狀瘤病毒大會上公佈。 該研究包括肯尼亞 2,275 名年齡在 15 至 20 歲之間的人。 他們被隨機分配接受三種治療中的一種：針對兩種 HPV 毒株的單劑量疫苗、針對九種毒株的單劑量 HPV 疫苗或對照疫苗。 參與者定期接受為期 3 年的測試。 研究人員報告說，雙株疫苗的有效性為 98%，九株疫苗的有效性為 96%。

去年 12 月，世界衛生組織將其推薦的 HPV 疫苗劑量減少到一劑，當時指出 2021 年全世界只有 15% 的女孩接種了疫苗。

「遵循 WHO 支持單劑量 HPV 疫苗接種方案的建議，可以透過降低成本、減輕供應壓力並使疫苗更容易接種，幫助全世界的婦女和女孩更容易獲得疫苗」，Peter Dull 資助這項研究的比爾和梅琳達·蓋茨基金會臨床疫苗開發副主任、醫學博士在一份聲明中說。

據《紐約時報》報導，至少有 24 個國家已經採用了單劑量方法。 該報稱，預計 2025 年將獲得更多研究結果，包括對多劑量與單劑量保護進行正式的科學測試。

文獻來源：

肯尼亞醫學研究所：「新研究發現，單劑量 HPV 疫苗在三年內非常有效」。

馬薩諸塞州總醫院：「研究焦點：單劑量 HPV 在保護年輕女性方面非常有效」。

世界衛生組織：「世衛組織更新了關於 HPV 疫苗接種時間表的建議」。

紐約時報：「一劑 HPV 疫苗可預防感染至少三年」。

Single Dose of HPV Vaccine Is Highly Effective: Study

Lisa O’Mary / May 03, 2023 / News /  WebMD Health News

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.”