With genetic alterations that may reduce the efficacy of the primary flu antiviral that hospitals rely on, at least two human cases of the novel H1N1 influenza strains, dubbed “dual mutants,” have been found in U.S. patients, the Centers for Disease Control and Prevention reported on Wednesday.
Published this week in the agency’s Emerging Infectious Diseases journal, an examination of the novel H1N1 flu viruses with these two alarming mutations—which scientists have named I223V and S247N, referring to modifications to the virus’s surface proteins—was conducted.
It comes after a study by Hong Kong experts who conducted the initial testing on the alterations.
Their March publication on lab research revealed that both changes seemed to increase H1N1’s resistance to the flu medication oseltamivir, which is marketed by pharmaceutical company Roche as Tamiflu.
The extent to which the alterations may reduce oseltamivir’s efficacy in the actual world is unknown. The altered viruses were shown to be up to 16 times less sensitive to the antiviral in the lab testing, which is a lesser dropoff than in some other concerning changes.
The altered viruses continued to be sensitive to baloxavir marboxil, a more recent anti-influenza drug. In an email, a CDC representative stated, “These mutated viruses retained sensitivity to other anti-influenza medications, including a newer one, baloxavir marboxil. There are no immediate implications to change decisions for clinical care.”
Cases spanning several continents
The CDC’s assessment on the new dual mutant flu strains revealed that although there has been a “rapid spread of dual mutants to countries on different continents,” the mutations seem to be infrequent for the time being.
As of May 2023, 101 sequences from Africa, Asia, Europe, North America, and Oceania have been added to the global virus database GISAID, following the discovery of the mutations in a case taken from the Canadian province of British Columbia. During that period, they comprise fewer than 1% of the flu virus sequences.
This past fall and winter, laboratories at the University of Michigan and the Connecticut Department of Health discovered the two U.S. cases.
“It is unknown how widely these mutated viruses will circulate in the upcoming season. It is important to continue monitoring the spread of these viruses and the evolution of these viruses,” the CDC spokesperson stated.
Read Also: Cocaine Trafficking Suspect Surrenders After High-Speed Chase on I-10
The most often recommended antiviral
For a considerable amount of time, the CDC has been monitoring any changes to the flu virus that might result in resistance to oseltamivir.
According to the CDC, oseltamivir is the most often given flu medication. According to a report released last year, 99.8% of pediatric flu antivirals were prescribed with this medication.
The Centers for Disease Control and Prevention (CDC) advises physicians to promptly administer flu antivirals to hospitalized or critically ill patients. Oseltamivir is another medication that doctors are using to treat those afflicted by this year’s H5N1 avian flu outbreak on dairy farms.
Health authorities have previously kept tabs on the appearance of a possible threat to the efficacy of flu medications.
Health authorities from Europe to Japan reported detecting surges of an oseltamivir-resistant H1N1 strain in 2007 and 2008, before it was wiped off the map by a competing variant that caused the swine flu pandemic that swept the world in 2009.
In lab studies, that strain’s H275Y mutation made it up to 1,000 times less sensitive to oseltamivir at the time.
Reference: CBS
