The virologist and cancer researcher Dr Jian Zhou had an important goal after creating a vaccine for the cancer-causing human papillomavirus in a Queensland laboratory.
He wanted to see the vaccine made widely available in his home country of China, which today accounts for more than 28% of the world’s cervical cancer cases. Cervical cancer is also the second most common cancer in Chinese women aged between 15 and 44.
The virus, commonly known as HPV, causes 5% of cancers worldwide, the main one being cervical, but it also increases the risk of vulva, penile, anal and throat cancers.
China has a notoriously lengthy and difficult drug approval process, with drugs first required to have been approved and marketed in another country and also required to pass separate Chinese clinical trials. It means the vaccine has never been available on the mainland.
Monday marks the 10-year anniversary of the vaccine being released in Australia, and research led by the Royal Woman’s hospital in Victoria and published to coincide with the anniversary has found that HPV infection rates have plummeted.
In countries such as Australia, where there has been high uptake of the vaccination thanks to free vaccination programs for all 12-year-old schoolchildren, infection rates have fallen by up to 90%, the researchers say. They found similarly significant decreases in genital warts and cervical abnormalities in many of the 129 countries they examined.
In China, however, women have been forced to travel to Hong Kong and pay hundreds of dollars for the three injections required for full vaccination, and the number of HPV-related cancers remains high.
July saw a breakthrough, with the China Food and Drug Administration approving the pharmaceutical giant GlaxoSmithKline to sell its HPV vaccine Cervarix domestically. It will be available on the Chinese market from next year.
Zhou did not live to see his vaccine make it to China. He died in 1999 aged just 42 after suffering from an illness, after the science of his vaccine had been proven but before its commercial release. He was recognised posthumously for his work at a commemorative service in 2008 at Parliament House in Brisbane.
His collaborator in creating the HPV vaccine, the University of Queensland professor Ian Frazer, told Guardian Australia he was saddened that Zhou did not see vaccine being delivered or its impact a decade on. Frazer, who was named Australian of the Year in 2006 for his role in inventing the vaccine, has always pointed out that Zhou equally contributed to the discovery.
“It is important to realise this was a partnership and we were equal partners in the game,” Frazer said. “He was a very self-effacing individual and he would never have wanted to take any credit, but he was always sure it – the vaccine – would work.
“The major challenge, from his point of view, was making sure it was made available in China. And this year he has finally been vindicated in that sense, with China deciding they will put out the vaccine.”
The pair were also aided throughout their research by Zhou’s wife and research partner, Dr Xiao Yi Sun, who followed Zhou’s instructions to assemble two proteins to create a virus-like particle resembling the HPV shell. When introduced into the human body, the particles simulated an immunological response that formed the basis of the vaccine.
The latest review of the vaccine, led by Prof Suzanne Garland, director of microbiological research at the Royal Women’s hospital in Melbourne, found that more than 187m doses of the vaccine had been administered in 129 countries, leading to significant declines in HPV. But many developing countries still did not have access to the vaccine, the authors of the study wrote.
“The full public health potential of HPV vaccination is not yet realised,” the review concluded. “HPV-related disease remains a significant source of morbidity and mortality in developing and developed nations, underscoring the need for HPV vaccination programs with high population coverage.”
Frazer agreed that this was the major challenge for the HPV vaccine moving forward. It would require not only the funding for the vaccine in those developing countries but the development of youth-targeted health programs, as the vaccine is most effective before people become sexually active – at which point they are at risk of contracting the virus.
“All the evidence from Australia shows us the vaccine has virtually eradicated infection among young people, and has sharply reduced the incidence of cancers,” he said. “That’s a cause for celebration. The evidence is clear that this vaccine is also very safe. We now must make sure it is delivered more widely.”
Frazer’s work is now focused on developing a vaccine for herpes, which is in phase two of clinical trials, meaning it is being tested on several hundred people to determine its efficacy and to further evaluate its safety.
HPV infection rates plummet after vaccine with China the next frontier
Hiç yorum yok:
Yorum Gönder