Study Finds Baloxavir Lowers Transmission of Influenza

June 9, 2025
This research expands the rationale for using this specific antiviral, which requires only one dose and shortens duration of infection.

Research in the New England Journal of Medicine has found that “one dose of the antiviral baloxavir marboxil lowers the chance of transmitting the influenza virus to family members by about 30%.”

The study involved 1,457 influenza positive patients and 2,681 household contacts. The patients were “randomly given either baloxavir or a placebo, and their contacts were followed to detect influenza transmission.”

Up to this point, “it has been unclear whether there was any reduction in transmission from the sick person. It also was not clear whether this was because no study was designed specifically to look for reduction in spread, or if no spread was taking place.” This study established that transmission could indeed be reduced.

Adam Lauring, one of the study’s co-authors, said that this study “highlights how we could potentially use an antiviral to help not just our patients but also households and larger communities by preventing influenza transmission.” Baloxavir is also a single dose compared to a daily dose for five days, which other flu antivirals require. This study, then, “extend[s] the rationale” for treating influenza patients with the antiviral, as it both shortens the duration of the illness and reduces transmission. Baloxavir also “prevents the replication” of avian flu, which could prove useful.

About the Author

Matt MacKenzie | Associate Editor

Matt is Associate Editor for Healthcare Purchasing News.