Anton and Nina speak English to each other when other people are within earshot. While this might seem implausible in a Russian lab, Nina obviously has some leeway in communicating with Anton, and others in the lab are aware that she is supposed to be talking to Anton. They would not be alarmed or suspicious of Nina and Anton speaking English to each other. And while they do talk quietly to each other this way, they are not overly secretive or paranoid about being overheard.
When Gabriel gives Elizabeth a vaccination shot, the needle visibly moves after it is supposed to have pierced the skin. This reveals the use of a retractable syringe prop.
Burkholderia mallei was known as Pseudomonas mallei until the 1990's.