Since it was released in the market around two decades ago, Roche's Tamiflu has become the go-to drug for influenza treatment. Its effectiveness, however, is challenged by mutated strains.
Each season, the genome sequencing of a flu virus changes as it creates copies of itself, resulting in a new strain with a resistance to antiviral medication or vaccines.
H3N2 Mutation: Cause Behind The Flu Epidemic
Such is the case of the 2017-2018 season, when the Influenza A or H3N2 strain mutated and caused an epidemic sweeping through the entire nation.
Fortunately, the CDC records that a hundred percent of those infected by the main strain and its mutations were responsive to existing anti-flu medications such as oseltamivir, zanamivir, and peramivir.
After dealing with the consequences of mutation, scientists pushed for the creation of anti-flu drugs that use entirely new mechanisms to fight influenza.
Nearly all anti-flu drugs work the same way. Tamiflu, Relenza, Rapivab, and Inavir inhibit the function of neuraminidase, an enzyme that allows germs to spread the infection from one cell to another.
The Antiviral Pill That Outdoes Tamiflu
Tamiflu cuts the duration of infection to a single day when administered within 48 hours following the onset of flu symptoms.
For it to work, two doses of the drug must be taken daily for five days. This presents a huge dilemma in terms of patient compliance.
Baloxavir, an experimental drug by Osaka-based pharmaceutical company Shionogi, could be available for release in Japan this March. However, it won't reach U.S. shores until 2019.
Unlike Tamiflu, the medication works by blocking the activity of the protein the influenza virus needs to create copies of itself. All a patient needs is a single dose.
"You don't have the potential resistance that comes with not completing your course of therapy," says Daniel O'Day, head of Roche's pharmaceutical department.
More Alternative Treatment for Influenza
Johnson & Johnson's Janssen also has a new anti-flu drug entering the market called pimodivir. It attacks the part of a gene found in almost all seasonal viruses that prevent them from creating any duplicates.
Because of its potential in addressing an urgent health issue, the U.S. Food and Drug Administration has designated it as a fast-track medication. It is expected to be in the last stages of study within this year.
Besides pimodivir, an anti-diarrhea treatment known as nitazoxanide shows some promise in blocking the development of the illness by stopping viral particles from escaping contaminated cells.
Romark Laboratories tested the drug on more than 300 participants a couple of years ago, but no results were indicated in the study's paper at the U.S. National Library of Medicine.
A universal influenza vaccine is currently in the works, with ferritin as its main component. The latest update states it is still being tested on animals. Should future human trials be successful, its single dose may replace annual shots.