The series is set during the Cold War and follows Elizabeth and Philip Jennings, two Soviet KGB intelligence officers posing as an American married couple living in Falls Church, a Virginia suburb of Washington, D.C., with their American-born children Paige and Henry.
According to Nielsen Media Research, the episode was seen by an estimated 1.04 million household viewers and gained a 0.3 ratings share among adults aged 18–49.
The episode received universal acclaim, with critics praising Annet Mahendru's performance and the end to Nina's arc.
Philip (Matthew Rhys), Elizabeth (Keri Russell) and William (Dylan Baker) are forced to stay with Gabriel (Frank Langella) at his apartment after their exposure to glanders.
In March 2016, FX confirmed that the fourth episode of the season would be titled "Chloramphenicol", and that it would be written by Tracey Scott Wilson, and directed by Stefan Schwartz.
The site's consensus states: "'Chloramphenicol' delivers a shocker of an ending that turns The Americans on its head in a dynamic, pivotal episode.
That's how powerful everything is for the show stateside right now – how perpetually on the verge of death, discovery, or both Elizabeth and Philip seem to be – and how strong the execution continues to be in terms of acting, writing, and directing.
"[10] Mike Hale of The New York Times wrote, "The Americans has the body count you’d expect from a show about Cold War espionage, but it had avoided killing off central characters.
"[11] Genevieve Koski of Vulture gave the episode a perfect 5 star rating out of 5 and wrote, "'Chloramphenicol' makes the inevitable feel legitimately shocking, and that's almost entirely attributable to the way its final sequence is staged.
"[12] Ben Travers of IndieWire gave the episode an "A" grade and wrote, "Will their choice to let Pastor Tim and his wife live be their own undoing?
We'll find out in the coming weeks, but — for as saddened as we are to see the great talents of Annet Mahendru leave the series — Season 4 just got a whole heckuva lot more virulent (which, we really didn't think was possible).
"[13] Matt Brennan of Slant Magazine wrote, "Though The Americans has rarely gone in for the chronological leaps familiar from Mad Men, Masters of Sex, and Halt and Catch Fire, this noticeable compression of events would seem to mark a new stage in the show's evolution.