The invention provides structurally constrained viral peptides for use as therapeutic and vaccination agents, and for the production of antibodies for use in a number of applications including as therapeutic agents. The invention further provides methods and kits for use of the structurally constrained peptides and antibodies of the instant invention. The invention is based, at least in part, on the result provided herein demonstrating that viral hydrocarbon stapled helical peptides display excellent proteolytic, acid, and thermal stability, restore the native helical structure of the peptide, are highly effective in interfering with the viral fusogenic process, and possess superior pharmacokinetic properties compared to the corresponding unmodified peptides.