Within five years there may well be a safe and effective vaccine for HIV and if there is, it could be thanks to the work of Dr. Chil-Yong Kang and his team of researchers at the University of Western Ontario’s Schulich School of Medicine and Dentistry.
This month, human clinical trials begin in the USA for SAV001, the name of the vaccine developed at UWO.
It’s been a long time coming. For more than 25 years scientists from all over the world have been trying to develop a vaccine against HIV as the number of people infected – and dying – of the virus has continued to grow.
To date, there have been three human clinical trials for an HIV vaccine. All of them have failed.
Dr. Kang is optimistic the UWO vaccine will be successful.
“We are using a totally different approach,” he says.
Unlike the failed attempts that used just certain genes or proteins from the virus, the UWO vaccine uses the whole virus (HIV-1).
“We infect the cells with a genetically modified HIV-1,” explains Kang. “The infected cells produce lots of virus, which we collect, purify and inactivate so that the vaccine won’t cause AIDS in recipients, but will trigger immune responses.”
It’s called the ‘killed whole virus vaccine’ approach and it’s similar to the one used to make vaccines for polio, influenza, hepatitis A and rabies. But it poses a unique challenge when it comes to HIV. There is no animal model for testing its effectiveness.
In other words, the vaccine can only be tested using humans to determine whether or not it works.
The USA’sFood and Drug Administration (FDA) gave the go-ahead for human clinical trials based on early results that showed the vaccine stimulated a strong immune response in animals with no adverse effects.
SAV001 will undergo three phases of human clinical trials. Phase I will involve 40 HIV-positive people and will test the vaccine’s safety. Phase II will test immune responses in 600 HIV-negative people, and Phase III will test effectiveness, using 6,000 HIV-negative people at high risk of contracting the virus.
For Dr. Kang, it’s been a long journey to get to this point. The respected virologist left Korea 50 years ago to study veterinary science in Denmark. That’s where he got interested in infectious diseases and decided that research would be his field.
He applied for and got a job as a research assistant at the University of Toronto’s famed Connaught Laboratories. There, he worked on the polio and measles vaccines – and got hooked on studying viruses.
For the next 20 years he pursued his passion, first at McMaster University as a graduate student, then the University of Wisconsin as a post-doctoral fellow, and then at the University of Texas Southwestern Medical School as a professor.
“It was the dawn of molecular virology,” says Kang. “It was such an exciting time to be in the field.”
While on sabbatical leave at the USA’s National Institutes of Health, one of the world’s foremost research centres, Kang got a call from the University of Ottawa. Was he interested in returning to Canada and chairing the Department of Microbiology and Immunology? He was ready to come home.
Over the next 10 years he built the department from the ground up and worked on several viruses including RNA tumour viruses, the same family of viruses as HIV-1.
In 1992 – nine years after the discovery of the HIV-1 gene and with no vaccine in sight – Kang was recruited by the University of Western Ontario as Dean of Science, where he started to focus on developing an HIV vaccine.
“My team had a background on retroviruses that enabled us to see the problem of developing an HIV vaccine from all angles,” he says, “and we learned from the three failed attempts as well.
“We thought that if ‘killed whole virus’ worked for other infectious diseases, why not HIV?”
Time will tell. And if Dr. Kang and his team are right, they will have accomplished something no other scientists have.
It will be quite a coup for an unassuming man whose first dream was to become a veterinarian.