TOKYO >> Work to develop vaccines and treatments for COVID-19 in the form of a nasal spray is underway.

Currently available vaccines are highly effective, but there is concern that more contagious variants of the virus could develop, and scientist are focused on creating new medications that can prevent infections, in addition to those for treating patients who have the disease.

When people receive a vaccination, IgG antibodies usually increase in their blood. But only small quantities of antibodies are present in the membranes of the nose and the throat, where incoming virus initially attach.

If another antibody — IgA, excreted by membranes — is produced in the nose and the throat, it could possibly prevent infection.

Researchers, led by virologist Tetsuya Nosaka of Mie University, and startup BioComo Inc. are developing a nasal spray vaccine to increase IgA antibodies primarily in nasal membranes.

In animal experiments, the vaccine increased IgA antibodies in membranes. When the novel coronavirus was introduced after two doses of the vaccine, virtually no virus was detected in nasal membranes three days later.

“A nasal spray is less of a physical burden than an injection,” said Nosaka. “We want to start clinical tests within a year.”

Another nasal spray vaccine is being developed by HanaVax Inc., a startup that originated at the University of Tokyo, with Shionogi & Co. set to manufacture it.

Overseas, the University of Oxford and the University of Hong Kong have begun clinical tests of a nasal vaccine.

Meanwhile, researchers led by Motoki Takagi, an expert in drug development science at Fukushima Medical University, are developing a preventative nasal medication that sprays IgA antibodies directly into the nose.

The researchers succeeded in mass-producing IgA antibodies after extracting antibodies from the blood of COVID-19 patients.

In July, they also test- produced masks with filters containing IgA antibodies. They hope to bring the product to market.

Finally, Shionogi & Co. is developing an oral COVID-19 medication for patients with mild symptoms that would curb the propagation of the virus. The company plans to begin distributing it this fiscal year.

The company is set to start manufacturing the drug by the end of 2021 and plans to stock enough supply to treat 1 million people.

“If we can supply a safe oral drug from around next January to March, then (coping with the coronavirus) will be completely different,” said Isao Teshirogi, Shionogi’s president and chief executive officer.

The company began clinical tests in July and entered second- and third-phase trials earlier this month. Shionogi is planning to start clinical tests on the drug overseas as well, and hopes to obtain special approval for emergency use in the United States and other countries.