Author: Sue Segar
In 2013, whilst attending a conference in Yokohama, the leading Japanese immunologist and vaccine developer, Professor Yasuhiro Yasutomi, told the South African singer and humanitarian, Yvonne Chaka Chaka, (also a speaker at the conference), that his life’s goal was to find a vaccine for HIV.
The 5th Tokyo International Conference on African Development (TICAD), had focused on boosting economic ties between Africa and Japan. Yasutomi gave a presentation on the progress he had made in his work on a vaccine for TB and Chaka Chaka, herself a champion in the fight against HIV and TB, gave an overview on the situation of TB in Africa.
“She gave us a song too. She had such a beautiful voice,” Yasutomi said in an interview. “Afterwards, we had a personal conversation and I told her I was working on a vaccine for TB. “I said to her, ‘do you like injections?’ and she said ‘no!’ So I said, ‘well, my vaccine is an internasal vaccine. No injections are involved.’ “I also told her that my next big goal was to find a vaccine for HIV.”
Fast forward to today and Professor Yasutomi, director of Japan’s Laboratory of Immuno-regulation and Vaccine Research, has, with his team, recently released promising results from their work on an HIV vaccine. Their findings lay open the possibility of a therapeutic vaccine against AIDS. To date, no live vaccine for the AIDS virus has been developed and the vaccine developed by Yasutomi’s team has the potential, he believes, to enable a discontinuation of lifelong dosing in patients.
The laboratory, situated in Ibaraki, Japan, is one of the foremost research centres into infectious diseases in the world.
Researchers across the globe have spent decades trying to develop an HIV vaccine. Considerable resources have been poured into this pursuit since the first official report on AIDS came out in 1981, but scientists have had no joy in “cracking” an effective HIV vaccine. This is due, among other things, to the genetic diversity of the virus, which is greater than that of any other pathogen.
While anti-retroviral therapy has led to a huge reduction in HIV-related morbidity and mortality, there is still no cure for the 40-year unchecked epidemic and HIV remains a major global health problem infecting 37,7 million people, according to 2020 figures, with more than two-thirds of infected people living in Africa. While it can be controlled with anti-HIV drugs, there is no cure for HIV infection.
A recent paper in the journal Nature describes the research by Professor Yasutomi and his team into a new vaccine technology that eliminated the HIV virus in crab-eating macaques, test monkeys which are native to Southeast Asia. The paper is entitled Long-term protective immunity induced by an adjuvant-containing live-attenuated AIDS virus.
Professor Yasutomi presented the results of his ground-breaking research at a webinar hosted by the Japanese Embassy and Stellenbosch University in March 2022
Milestones in HIV treatment and prevention research Implications for global public health
In this webinar, expects share their work on HIV treatment and prevention and the advances towards HIV immunity.
Professor Yasuhiro Yasutomi, director of the Laboratory of Immuno regulation and Vaccine Research (NIBIOHN, Japan) presented results on the development of an HIV vaccine.
Professor Glenda Gray, CEO, and President of the South African Medical Research Council (SAMRC) speaks about her work in HIV vaccine research and treatment strategies in Southern Africa.
Prof Nico Gey van Pittius, Professor in Molecular Biology and Vice Dean: Research and Internationalisation at Stellenbosch University’s Faculty of Medicine and Health Sciences, facilitated the discussion.
The discussion highlights both the milestones and challenges in science’s response to the HIV epidemic and implications for global public health ahead.
The team’s research involves a bacterium that secretes an immune-strengthening substance (known as an adjuvant or a substance that enhances an immune response). The team produced a vaccine by mixing genes of this bacterium with genes of a weakened AIDS-causing virus. The monkeys became infected with HIV when the vaccine was administered on them, but later tests did not detect the virus and strong cellular immune responses were induced.
Six of the seven vaccinated monkeys, when infected with a stronger virus that invariably kills the victim, survived.
Blood and lymph node cells were taken from the six monkeys and injected into healthy monkeys. Four of them were found to be free of the virus.
“This means that more than 85% did not develop AIDS even without antiviral agents,” Professor Yasutomi said.
He hopes that the same effect can be obtained in humans. His team hopes to create vaccines by using HIV from patients who are on drug treatment with a view to using these vaccines as another method of treatment.
Professor Yasutomi hopes to begin clinical testing on humans within five years. Initially, this will be done in Japan in the form of a tailor-made vaccine for individual patients. “After that, we plan to make a vaccine from the common sequence and move to a large group. At that time, I would like to target African countries,” he said.
Professor Yasutomi (61), who describes himself as “a vaccinologist whose hobby is motorcycling”, was born in the large port city of Osaka, in the west of Japan. He grew up surrounded by pets and originally wanted to become a veterinarian because of his love of all animals. He completed his M.Sc in Veterinary Science in 1986 followed by a Ph.D in Veterinary Immunology in 1990.
He first focussed on tuberculosis and started working on the development of a vaccine for TB, with his main goal of bringing it to Africa, the continent which has the highest prevalence of TB (and HIV) and a continent for which, he said, he has developed a real heart. His research has brought him to South Africa and he has met with a number of top TB researchers here.
He had closely followed the global development of the AIDS virus since the early 80’s. “The famous actors and singers, like Freddy Mercury died from HIV … and then it became such a terrible problem in Africa.”
So, he switched to the field of human immunology and, in 1990, went as a research fellow to the medical faculty at Harvard University’s New England Regional Research Centre.
Having focussed on TB antigens and the strong immune responses they evoke, he decided, in the early 1990s, to take his strong body of knowledge into the area of HIV.
Between 1992 and 1996, he worked as an instructor at Harvard’s research centre. In 1996, he moved to the department of Bioregulation at Mie University School of Medicine in Japan. In 2007, Professor Yasutomi became Professor in Immunology in the same department. He has also been, since 2007, the Director of the Tsukuba Primate Research Centre, at the National Institute of Biomedical Innovation, in Ibaraki, Japan. Besides his passion for motorcycling, he is keen on Japanese martial arts and loves travelling to foreign countries. A favourite trip was to Kenya where he was amazed at the wildlife.
Professor Yasutomi hopes that the findings of his research will be a game changer in the battle against HIV. “My fingers are crossed. I believe our research shows new possibilities in vaccinology and AIDS treatment,” he said. “I am hoping that AIDS treatment will be simplified and that newly infected people will be strongly protected from the virus.”
HIV rates are not high in Japan, but it is for Africa, which he calls “the mother continent”, that he wishes to succeed in his work.He believes he is not far from developing an HIV vaccine. “From wishful thinking, the direction of the goal is becoming clear.” Professor Yasutomi paid tribute to SA researchers working on a vaccine for HIV and stressed his commitment to a strong collaboration between Japanese and SA researchers.
“Maybe our next step for clinical trials will be in your country,” he said. “We need African people’s help as we need many patients and also we have to help the people infected with HIV.”
Professor Glenda Gray, President of the South African Medical Research Council, (SAMRC) and a Co-Principal Investigator of the HIV Vaccine Trials Network (HVTN), a transnational collaboration for the development of HIV/AIDS prevention vaccines stated in the webinar that 2021 had been a “pivotal” year for HIV vaccine development. She said there had been a huge expansion of HIV vaccine clinical research sites in Africa that have been developed to do the phase three trials that have been conducted in recent years.
“I am very heartened to see that Japan is interested in looking at HIV vaccines and is interested in trying to find solutions as these problems are our problems in Africa. We do need to collaborate with countries like Japan and work with scientists from Japan and others. We need to work with scientists who are developing novel approaches and support the clinical development,” she said.
Professor Yasutomi, who intends spending more time on the continent in his research and who cannot wait to motor around South Africa on a Harley Davidson, said: “We have to find a way to finally terminate this virus. Today there are many vaccine candidates around the world and we have made enormous progress, but no one knows which will lead to the real effective vaccine. I hope to demonstrate some very, very exciting results within five years. It is getting very close.”