Ann Arbor Times

One dose of the antiviral drug Baloxavir Marboxil can reduce the transmission of the influenza virus to family members by approximately 30%, according to a study published in the New England Journal of Medicine. This Phase III global trial, known as the CENTERSTONE trial, was led by University of Michigan epidemiologist Arnold Monto. The study focused on 1,457 influenza-positive patients aged 5 to 64 and their 2,681 household contacts. Participants were randomly assigned either the antiviral drug or a placebo to evaluate the possibility of influenza transmission.

“There’s always been a question, could antivirals, which are known to shorten duration of influenza when used early in treatment, also prevent the spread of influenza,” explained Monto, who has served as an adviser to the Centers for Disease Control and Prevention and the Federal Drug Administration.

Monto added that it had previously been unclear if influenza treatment could reduce transmission, either due to a lack of targeted studies or potentially because no transmission was occurring.

“Our study was designed to directly evaluate whether this meant we could finally establish that transmission could be reduced, and we were finally able to show that it was,” Monto stated.

Adam Lauring, co-author and chief of the Division of Infectious Diseases at the U-M Medical School, emphasized the study's significance in potentially lowering flu incidence. Lauring, a professor of internal medicine, microbiology, and immunology, commented, “It highlights how we could potentially use an antiviral to help not just our patients but also households and larger communities by preventing influenza transmission. It could change how we approach future influenza outbreaks.”

Monto further noted that because Baloxavir requires just a single dose, unlike other antivirals that require daily doses over five days, it could see broader usage. This could lead to not only protecting oneself from complications but also safeguarding others.

“These findings extend the rationale for treating influenza patients with the antiviral. It’s a twofer: shortening the duration of the illness, which can also prevent complications leading to hospitalizations or deaths, while also reducing transmission,” he elaborated.

Monto also pointed out that an antiviral reducing viral shedding shows potential in combating the spread of avian flu, although studies have not been conducted on Baloxavir's effects on avian influenza or its impact on birds and dairy cattle. Laboratory studies have indicated that Baloxavir may prevent the replication of similar flu viruses.

The study received funding from both Roche, the drug's manufacturer, and the Center for the Biomedical Advanced Research and Development Authority, a part of the Department of Health and Human Services.