"Infection" marks the first mention of Interplanetary Expeditions, or IPX, an archaeological research corporation with ties to secret government projects and weapons research. The company is featured prominently in the third season episode "Messages from Earth."
Garibaldi has been fired from 5 different jobs for "unspecified personal problems" (later revealed to be his alcoholism). His assignment on Babylon 5 is probably his last shot in Earth Force.
The Vorlons have technology based on organic systems, and there is a strong hint that the Minbari do as well.
Towards the end of the episode, Garibaldi comments on Sinclair's rash bravery, which seemed common among veterans of the Earth-Minbari War. He notes, "I think they're looking for something worth dying for because it's easier than finding something worth living for." This line of thinking is repeated by Lorien in the Season 4 episode Whatever Happened to Mr. Garibaldi?
"Infection" was the first regular episode of Babylon 5 to be filmed. Coincidentally, guest star Marshall R. Teague also appeared in "Objects at Rest", the final episode of the series to be filmed, in which he played Ta'Lon.
A reference to Star Trek technical consultant Michael Okuda can be seen when a medical scan of the alien artefact shows "Okudazin" as one of the contents. Okuda himself inserted many in jokes into the LCARS computer displays for Star Trek referencing other science fiction franchises.