By Roky Goda and Hisatoshi Kabata, staff writers
Efforts to develop a vaccine against the new coronavirus are underway globally. Vaccinating with weakened or dead microbes will result in development of an immunity inside the human body that resembles what would be gained from an actual infection. According to the World Health Organization (WHO), there are more than 70 vaccine development plans in the world targeting the new coronavirus. In Japan, Osaka University is leading the effort, with three vaccines under development. The Asahi Shimbun interviewed two leading figures of the university’s vaccine efforts, Prof. Yoshiharu Matsuura of the university’s Research Institute for Microbial Diseases and Osaka University School of Medicine Vice-President Yasufumi Kaneda, who is also a gene therapy specialist. We asked their views on vaccine development.
We can develop multiple DNA vaccine variations as early as next year. Meanwhile, we need to provide broader support to increase researchers.
Q: What are the three vaccines you are developing at Osaka University?
Kaneda: They are an inactivated vaccine, a VLP (virus-like particle) vaccine that replicates the virus’s structural capsid protein, and a DNA vaccine that stimulates the human body to reproduce part of the virus. We are currently evaluating the effects of the DNA vaccine on strengthening and multiplying the protective antibody. We estimate that about six more months are needed before we start clinical trials with human subjects. If we can determine the vaccine’s efficacy and safety, it may become available for general use possibly by the beginning or around this time next year. We can front-load the schedule if we start mass production as soon as the results of the trial become available.
Matsuura: The VLP vaccine study will take two to three months to determine the efficacy on mice. It will be three years or so before we can start clinical trials with human subjects. The inactivated vaccine is currently at the stage where we repeat the infection process with cultured cells to determine optimal conditions for virus growth. This process takes time, and it will also be at least three years before we can start clinical trials. Usually, it takes about ten years from the start of a clinical trial to obtaining approval. However, the need for a vaccine is urgent, so we hope for the application of a “special measure” that enables us to quickly put the vaccine in use when its efficacy and safety are established.
Q: No other institution in Japan is trying to develop three kinds of vaccines concurrently.
Kaneda: We plan to launch them as soon as they are ready, one after another. We hope to accelerate the development process by taking advantage of many university-affiliated hospitals in the Osaka region for research and trials.
Sometimes a clinical trial ends with less-than optimal results. There is no one hundred percent guarantee of success. However, we must be aware that even when a vaccine becomes available overseas, it will first be provided to the domestic population, many of whom may be facing death, diminishing the likelihood that a sufficient amount of the vaccine reaches Japan. Japan must have its own vaccine capacity.
Q: It is said that a DNA vaccine is theoretically possible, but an actual product has yet to materialize. Is there an example of a VLP vaccine?
Kaneda: In Australia, a clinical trial is currently underway on a DNA vaccine against hypertension. We don’t know the final result yet, but mild efficacy is reported in trials with animals.
Matsuura: Two VLP vaccines have been approved in the U.S., one for influenza and the other for HPV (Human Papilloma Virus), which causes cancer.
Q: Are you not developing live vaccines?
Matsuura: Using a live virus means we must have a laboratory that meets the level 3 standard of the WHO’s biosafety level (BSL) for research laboratories, which is just below level 4, which, for example, includes the Ebola virus. The live virus has to be weakened through a repeated cell infection process. This takes time. Besides, there is a risk that a more toxic virus reemerges after immunization.
Q: Why was there no coronavirus vaccine in the past?
Matsuura: Generally, colds caused by a coronavirus present only mild symptoms, so there wasn’t a need for vaccination. Vaccines were sought for severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS), but when the outbreaks receded, everyone forgot about them. The new coronavirus is very closely related to SARS, so if a SARS vaccine had been successfully developed, we might have been able to use it for the new coronavirus.
Q: What is your view on Japan’s virus research?
Matsuura: There are very few researchers that study coronaviruses because it is very hard to get funding for coronavirus research. When we submit a funding application with the Japan Agency for Medical Research and Development (AMED), we are invariably asked a very awkward question, “So what is the merit of this study that will lead to an actual application?” In order to cope with a crisis like the current one, we cannot just always simply focus on the actual application of a vaccine. We must nurture researchers in a wide range of areas, including basic research.