May 20, 2026
TOKYO – The government said Monday it had provided part of its stockpile of the antiviral medication Avigan to Britain amid an outbreak of hantavirus on a cruise ship.
The Health, Labor and Welfare Ministry said that the drug may be used for pre-symptomatic infected individuals or those who came into close contact with infected persons.
Avigan was developed to treat a new strain of influenza and has also been approved for the treatment of a tick-borne infection called severe fever with thrombocytopenia syndrome. The medication inhibits the activity of enzymes that viruses use to replicate.
Although no clinical trials of the drug have been conducted on humans to treat hantavirus, animal studies have shown benefits from suppressing viral replication when administered within four days of infection.
In the hantavirus outbreak, a Japanese national was evacuated from the ship on a charter flight arranged by the British government. The provision of stockpiles is based on a memorandum of understanding between the ministry and the U.K. Health Security Agency.
Japan maintains a stockpile of Avigan to treat at least 2 million people with a new influenza strain. Although Japan has not disclosed in detail the amount of the drug provided to Britain, it said that there will be no shortage for domestic use.