Recent advances in avian influenza virus: Molecular pathogenesis, emerging strains, and next-generation therapeutics

Table 1 Comparative overview of current and emerging therapeutic strategies for avian influenza virus infection

Therapeutic agent/strategy	Mechanism of action	Targeted strains	Development stage	Resistance issues
Oseltamivir (Tamiflu)	Neuraminidase inhibitor – blocks virus release	H5N1, H7N9, H9N2	Approved	H275Y mutation reduces efficacy[69]
BaloxavirMarboxil	Cap-dependent endonuclease inhibitor	H5N6, H9N2, H1N1	Approved (limited use in AIV)	PA-I38T mutation linked to resistance[64]
Amantadine	M2 ion channel blocker – inhibits viral uncoating	H1–H3 (historic use)	Obsolete (due to resistance)	Widespread resistance in H5/H9[67]
Nitazoxanide	Host-targeted antiviral; interferon modulator	Multiple AIV subtypes	Clinical trials	Minimal–host-directed mechanism[68]
Monoclonal antibodies	Neutralize HA or NA epitopes	H5N1, H7N9, H5N6	Preclinical/early clinical	Escape mutants possible[65]
mRNA vaccines	Encode HA/NA antigens for in vivo expression	Broad-spectrum (experimental)	Preclinical/early clinical	No direct resistance yet observed[70]
Universal vaccines	Target conserved HA stalk/M2e epitopes	Multisubtype AIVs	Experimental	Incomplete efficacy in human trials

AIVs: Avian influenza viruses; HA: Hemagglutinin; NA: Not available.