Drug companies and research institutes around the world are scrambling to create a novel coronavirus vaccine. Clinical trials have started, and newspaper headlines every so often tout promising developments.

But despite the global efforts and collaborations, experts say a vaccine will likely not be available in Japan in time for the Tokyo Olympics now scheduled for next year, as Prime Minister Shinzo Abe has hoped.

Scientists must painstakingly ensure that the “cure” does not cause more damage. And they are dealing with a virus that still contains many mysteries.

Abe expressed his hope that a vaccine will become a reality in a year or so.

“Japan will proceed as a key player in the development of the vaccine since a drug to treat and vaccinate against the coronavirus will also be crucial in terms of making the Tokyo Olympics a success,” he said on an online program streamed on May 6.

Shinya Yamanaka, a Nobel Prize-winning stem cell biologist and director of Kyoto University’s Center for iPS Cell Research and Application, was skeptical.

“It will be difficult to prepare a supply of the coronavirus vaccine in an ample volume to make (the Tokyo Olympics) happen unless we have a series of extremely fortunate developments,” Yamanaka said on the same program.

As of May 5, biotechnology companies and research institutions, many of them in China and the United States, were conducting clinical trials for eight coronavirus vaccine candidates, according to the World Health Organization. In addition, about 100 vaccine candidates are known to exist.

The development of an ordinary vaccine is a time-consuming process because it makes use of the original virus. Before such drugs can be tested on people, researchers must ensure the safety of the vaccine candidate by determining if the virus could multiply in the human body.

For the novel coronavirus vaccine, many researchers are taking a new approach by relying on data on the virus’s genetic code and genetic engineering technology.

Since this method does not involve the use of the coronavirus itself, experts say it will significantly reduce the period of development.

In the United States, a biotech firm has started testing a potential vaccine on humans in partnership with the National Institutes of Health, using genetic material to instruct cells in the body to make specific coronavirus proteins.

They plan to make this vaccine available first to health care workers in autumn.

A research team at Oxford University started a clinical trial of a drug that was developed based on the genetic engineering technology.

Yasufumi Kaneda, a researcher specializing in gene therapy science at Osaka University, underscored the need for Japan to come up with its own vaccine candidates from a point of national security.

“Even if a coronavirus vaccine becomes available overseas, I am concerned that it may not be supplied to Japan,” he said. “Japan should have vaccine candidates of its own.”

In Japan, Osaka University and AnGes Inc., a biopharmaceutical startup affiliated with the university, began a project to develop a vaccine using the genetic code of the coronavirus.

Researchers in the project said they will need only half a year to move on to a clinical trial under this method. In comparison, it would take a year or two if the real virus were used in the drug.

Drug maker Shionogi & Co. and the National Institute of Infectious Diseases have joined forces in another vaccine project.

However, no vaccine has been put into practical use for a coronavirus that has afflicted humans.

Many countries raced to develop a vaccine against severe acute respiratory syndrome (SARS), caused by a coronavirus, when it spread around the world from 2002 to 2003.

But before the vaccine became available, the SARS outbreaks had been brought under control.

Tetsuo Nakayama, a professor of viral infection control at Kitasato University, said developing an effective vaccine against the new coronavirus will be an enormous task because many unknown factors remain.

“We still don’t know which method will be good to make an effective vaccine against the new coronavirus,” he said. “It is hard to say when we can come up with one.”

Confirming the safety and efficacy of a vaccine through clinical trials is imperative before it is ready for use among the general public.

The first phase of the clinical trial is designed to examine the vaccine’s safety. In the second phase, researchers assess the efficacy. In the third phase, both the safety and efficacy are evaluated through testing on more subjects.

The spread of the new coronavirus has been designated as a pandemic, meaning that the approval process for a vaccine will likely be shortened, and priority will be given to the new medicine over other drugs.

But researchers still must proceed carefully despite the overwhelming need for the vaccine.

Masayuki Miyasaka, a guest professor of immunology at Osaka University’s Immunology Frontier Research Center, cautioned against possible side effects.

“A vaccine will be used on healthy people,” he said. “The consequences will be grave if it causes serious side effects.”

Miyasaka noted that a clinical trial usually involves thousands of subjects.

He said it will take “more than two years” before a vaccine against the new coronavirus will be made available.