New HPV Vaccine Candidate Approach From China
Researchers at Xiamen University, located in China's Fujian Province, have taken a major step forward in developing a new-generation vaccine that has the potential to protect people against many forms of Human Papillomavirus (HPV).
There are more than 200 distinct HPV types of which at least 18 are high-risk types associated with the majority of cervical cancers, says Cancer.gov.
Dr. Xia Ningshao, the lead researcher in this pre-clinical, Xiamen University study, compared HPV or the vaccine to a "ball", reported Yuan Quan, with Xinhuanet.
All HPV types are similar in appearance but are significantly different in the surface of the "ball", such as veins, convex and concave areas.
The structural features on the surface are called loops.
"Because of the loops, one type of vaccine can stimulate the production of antibodies only against the infection of one type of virus, and is unable to prevent the infection of other types," said Dr. Ningshao.
Using a loop swapping approach, these Xiamen University researchers engineered a complex virus-like particle with the loops of 3 genetically close HPV types: HPV33, HPV58, and HPV52.
They tested the triple-type particle in experiments on mice and monkeys and found it could provide high immune potency, comparable with a combination of 3 virus-like particles.
The new approach was equally successful in developing another 4 triple-type particles using the other 12 major HPV types.
"This pre-clinical research paves the way for an improved HPV vaccine made of 7-type virus-like particles to protect against as many as 20 HPV types," said Dr. Xia.
The results were recently published in Nature Communications. Reviewers said the new-generation vaccine candidate was "a remarkable achievement" for having broader type coverage, lower cost and lower amounts of proteins and agents, and "will be moved forward into a clinical trial."
Three HPV vaccines have been introduced to China, covering 2, 4 and 9 types.
The Gardasil 9 vaccine from Merck is the current market-available HPV vaccine providing the broadest protection against infection from 9 HPV types, 7 of which can cause 90 percent of cervical cancers.
Gardasil was developed by Chinese cancer researcher Zhou Jian and Australian immunologist Ian Frazer.
The 3-shot HPV vaccination covering 9 types is priced for 3,894 yuan in China.
These researchers say the new-generation vaccine candidate will be available for women aged 9 to 45.
However, it remains unclear whether widespread immunization with vaccines like Gardasil 9 could lead to an increase in infection rates from the other cancer-related HPV types, responsible for the remaining 10 percent of cervical cancers.
Two HPV vaccines previously developed by Xiamen University have reached the clinical test stage and are expected to enter the market in 2019 and 2022.
In 1995, Zhou and Frazer started cooperating with Merck and Co. to develop the vaccine. After Zhou's sudden death from hepatitis in 1999, Frazer continued the work until the vaccine was ready for market.
Recent HPV vaccine news articles:
- Hong Kong’s HPV Vaccine Shortage Created a ‘Priceline’ Marketplace
- Therapeutic Vaccine Candidate for Precancerous Cervical Cells Study Launched
- Gen X’ers Can Now Get Cancer Prevention Vaccine
According to Cancer.org, more than 1.6 million people will be diagnosed with cancer in the United States during 2017.
The authors of this study declared no competing interests.
The data supporting the findings of this study are available from the corresponding authors upon reasonable request.
The corresponding author is Ningshao Xia - [email protected].