Photo/Illutration A silkworm pupa is used in vaccine research. (Provided by Takahiro Kusakabe)

FUKUOKA--Kyushu University has used silkworms to develop a protein that could become a candidate vaccine for COVID-19, officials said.

The university, known as a world-class institution for silkworm studies, hopes to start clinical research for the vaccine as early as fiscal 2021. The vaccine could be mass-produced at an “insect plant,” keeping down the cost per inoculation to only several thousand yen (tens of dollars).

Silkworms can produce target proteins in their bodies if they are injected with genetically engineered viruses.

Kyushu University researchers have been studying technologies to use such proteins to develop vaccines against hypothetical, new infectious diseases.

“People around the world are working to create vaccines, but speed is not our priority,” Takahiro Kusakabe, a professor of insect genome science who led the team, said at a news conference on June 26. “Our goal is stable production of cheap vaccines that could be used to inoculate populations, including in developing nations.”

The Kyushu University researchers studied the genetic information of the novel coronavirus, which was published in January, and set their sights on a “spike protein” shaped like a protuberance. The virus uses this when infecting human cells.

The scientists confirmed that silkworms bred at the university can generate that protein, the officials said.

Studies on a different type of coronavirus have already shown that an antibody formed by immune reaction in the bodies of mice that are given injections of its spike protein can effectively prevent infection with that virus.

Kyushu University plans to finish its COVID-19 tests on mice by the end of this year at the earliest. It seeks to tie up with pharmaceutical companies and start research on human subjects as early as next fiscal year.

In a separate development, another team of Kyushu University scientists, led by pharmacology professor Motohiro Nishida, said June 26 that they have identified three drugs that could prevent symptoms of COVID-19 infection from worsening. The drugs were from among a pool of 1,200 or so medicines already in use.

They said the three medicines are being used to treat, among other symptoms, respiratory failure and blood vessel inflammation, which are also seen in COVID-19 patients. The team hopes those drugs can be administered to such patients by the end of this year.