Influenza Antiviral Works Before and After Annual Flu Shots

Xofluza baloxavir marboxil treats influenza in children and adults
young kids giving thumbs up sign
by Anil Sharma
San Francisco (Precision Vaccinations News)

As the flu season approaches from the Southern Hemisphere this year, plenty of U.S. FDA-approved influenza vaccines are available to protect people.

However, anyone can get the flu before they are vaccinated, and occasionally even after.

To help reduce the severity of influenza in children, the FDA recently extended the use of a leading oral antiviral medicine.

On August 11, 2022, the FDA approved a supplemental New Drug Application for Genentech Inc.'s Xofluza® (baloxavir marboxil) for treating uncomplicated acute influenza in otherwise healthy children aged five to less than 12 years of age who have been symptomatic for no more than 48 hours. 

This approval marks the first single-dose oral influenza medicine approved for children in this age group.

Additionally, Xofluza was approved to prevent influenza in children aged five to less than 12 years following contact with someone with flu.

This approval is essential since there has been a rapid increase in influenza-related pediatric fatalities post-COVID-19.

During the 2021-2022 flu season, there have been (33) pediatric fatalities.

The previous flu season only confirmed (1) flu-related pediatric fatality.

"Historically, school-aged children have played a significant role in the community transmission of influenza," said Dr. Pedro Piedra, miniSTONE-2 study investigator and professor of molecular virology and microbiology, pediatrics at Baylor College of Medicine, reported PrecisionVaccinations on August 13, 2022.

"And the annual flu shot continues to be the most important first step to prevent illness in children."

"For the 2022-2023 season, the CDC recommends that all eligible persons aged six months and older should be vaccinated to prevent complications from influenza infection."

"However, there can still be breakthrough cases where antiviral treatment is needed."

"It's great to see the FDA's recent approval of Xofluza for the treatment of uncomplicated influenza in otherwise healthy children aged five to less than 12 years."

"This single-dose oral influenza medicine approval is an important tool for providers to treat adults as well."

Xofluza is being further studied in a Phase III development program, including children under the age of one.

As of today, it is not known if Xofluza is safe and effective for treating and preventing the flu in children under five years of age, says the company.

Levi Garraway, M.D., Ph.D., chief medical officer and head of Global Product Development, commented, "Xofluza has proven to be an important tool in fighting and preventing influenza in adults as well as adolescents, and we are pleased to now offer households and younger children our single-dose oral treatment."

Xofluza is a first-in-class, single-dose oral medicine with an innovative proposed mechanism of action that has demonstrated efficacy in a wide range of influenza viruses, including in vitro activity against oseltamivir-resistant strains and avian strains (H7N9, H5N1) in non-clinical studies.

Xofluza is the first in a class of antivirals designed to inhibit the cap-dependent endonuclease protein, which is essential for viral replication.

Genentech is a member of the Roche Group.

Influenza antivirals and vaccines are available at most pharmacies in the USA.

Additional flu season news is posted at

PrecisionVaccinations publishes fact-checked, research-based vaccine news curated for mobile readership.

Note: Updated for a technical correction on August 15, 2022.

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Article by
Donald Hackett