Photo/IllutrationA influenza virus (Provided by the Tokyo Metropolitan Institute of Public Health)

Pharmaceutical manufacturer Shionogi & Co. is set to market a one-step medication to contain influenza viruses that are playing havoc with the nation's health.

The new drug as yet to be named in English needs to be ingested only once, compared with Tamiflu, which must be taken twice daily over a five-day period.

Osaka-based Shionogi said it has high expectations the drug will combat influenza viruses that are resistant to current medicines on the market.

The company also expects that the drug will reduce the risk of contagion.

A health ministry panel gave the green light Feb. 2 for the manufacture and sale of the drug.

With formal ministry approval expected in March, it could be available as early as May--even though the flu season will largely be over by then.

The drug would target both A and B types of influenza viruses.

The dose will be determined by the age and weight of the patient.

Tamiflu is among the four most popular types of influenza medicine used in Japan. They work by suppressing the spread of the virus that has proliferated within each cell.

Amid fears the current influenza outbreak involves a virus resistant to conventional medicines, the new Shionogi drug is being hailed as one that offers the greatest chance of reducing widespread misery.

An influenza epidemic spread worldwide 10 years ago when a virus emerged in Europe that was resistant to Tamiflu.

Four years ago, a virus was detected in a patient in Sapporo that was also found to be resistant to Tamiflu and other conventional medicines.

The central and local governments are continuing with research into viruses resistant to influenza drugs now available.