Abstract: Provided is a method of contacting a subject, cell, or tissue with an amphiphilic block copolymer to treat a viral infection. The resulting effect can be treating a disease caused by a virus, inhibiting viral replication, inhibiting an unfolded protein response of a virus, preventing death of tissue infected by a virus, or promoting cell repair and recovery to increase survival of cells infected by a virus. The hydrophobic block of the amphiphilic block copolymer binds to an exposed hydrophobic domain of the virus. Further provided is an amphiphilic block copolymer comprising three or more hydrophobic substituents or an alkylene spacer on a hydrophobic block of the copolymer.