tetano
Editor, Senior Moderator
Open Forum Infect Dis
. 2026 Jul 1;13(7)
fag393.
doi: 10.1093/ofid/ofag393. eCollection 2026 Jul.
Oseltamivir Resistance in Human Influenza A(H5N1) and A(H7N9) Infections: A Mini Review
Yacine Abed[SUP] 1 [/SUP], Guy Boivin[SUP] 1 [/SUP]
Affiliations
Avian influenza viruses (AIVs) have been reported to cause infections in humans following avian-to-human transmission, resulting in a range of clinical outcomes. A(H5N1) and A(H7N9) infections, which constitute the majority of human AIV cases, are responsible for severe infections leading to high mortality. The neuraminidase inhibitor oseltamivir is expected to play a major role for the control of AIV infections in humans. However, the emergence of resistance may compromise the impact of antiviral therapy. The objective of this article is to review human cases of A(H5N1) and A(H7N9) infections for which mutations of oseltamivir resistance were detected. Neuraminidase mutations rapidly occurred in a subtype-specific manner, with H274Y and N294S substitutions predominating in A(H5N1) cases and the R292K substitution in A(H7N9) cases. Serious clinical outcomes and mortality were seen in most A(H5N1) and A(H7N9) cases despite oseltamivir therapy, thus highlighting the need for improving antiviral strategies against these AIVs.
Keywords: H5N1; H7N9; influenza; oseltamivir; resistance; treatment.
. 2026 Jul 1;13(7)
fag393.doi: 10.1093/ofid/ofag393. eCollection 2026 Jul.
Oseltamivir Resistance in Human Influenza A(H5N1) and A(H7N9) Infections: A Mini Review
Yacine Abed[SUP] 1 [/SUP], Guy Boivin[SUP] 1 [/SUP]
Affiliations
- PMID: 42491214
- PMCID: PMC13376673
- DOI: 10.1093/ofid/ofag393
Avian influenza viruses (AIVs) have been reported to cause infections in humans following avian-to-human transmission, resulting in a range of clinical outcomes. A(H5N1) and A(H7N9) infections, which constitute the majority of human AIV cases, are responsible for severe infections leading to high mortality. The neuraminidase inhibitor oseltamivir is expected to play a major role for the control of AIV infections in humans. However, the emergence of resistance may compromise the impact of antiviral therapy. The objective of this article is to review human cases of A(H5N1) and A(H7N9) infections for which mutations of oseltamivir resistance were detected. Neuraminidase mutations rapidly occurred in a subtype-specific manner, with H274Y and N294S substitutions predominating in A(H5N1) cases and the R292K substitution in A(H7N9) cases. Serious clinical outcomes and mortality were seen in most A(H5N1) and A(H7N9) cases despite oseltamivir therapy, thus highlighting the need for improving antiviral strategies against these AIVs.
Keywords: H5N1; H7N9; influenza; oseltamivir; resistance; treatment.