"Doc" Rios says that a synthetic lectin is preventing the cure from fighting the virus in people from Japan. Lectins are a specialized type of protein that bind to carbohydrates, specifically sugar groups that are part of larger molecules, their functions are diverse and lectins can be both beneficial or toxic depending on the exact type. Lectins play an important role in cell function and protein binding, they mediate cell adhesion, regulate production of glycoproteins, regulate blood protein levels and play an important role in the immune system as lectins are what a lot of bacteria and viruses use to bind themselves to cells. Lectins in the innate immune system are one of the first lines of defense against invading microorganisms, they help antibodies bind themselves to the surface of organisms that the immune system targets for destruction; some lectins can also be used to prevent a virus from binding itself to cells and reproducing. Lectins can also have negative, even deadly effects in the body as well, probably the best known example of a deadly lectin would be the chemical weapon ricin. Ricin is a naturally existing, highly toxic lectin found in the seeds of the caster oil plant; it acts as a toxin by inhibiting protein synthesis. It prevents cells from assembling amino acids into proteins by interfering with the messenger RNA in the cell's ribosome. Essentially it stops the most basic type of cell metabolism, which is how cells produce the energy they need to function and reproduce, a function essential for all life. Without the ability to metabolize proteins cells die very quickly without being able to produce new replacement cells.
When President Oliver first arrives at the White House by motorcade, he is greeted by a military honor guard consisting exclusively of sailors. This implies that no branch of the military other than the US Navy exists in a functional form as such an honor guard would necessarily consist of representatives of each branch of the military, with the US Marines given order of precedence.