CERA

CERA (Catastrophic Emergency Response Agency) is a federal agency which was created to deal with large-scale natural disasters. In Tom Clancy's The Division, they are the group most focused on halting and containing the spread of the Green Poison virus.

Pre-game Lore
CERA was created to help deal with large-scale natural disasters, when the situation was overwhelming local and state relief efforts. It can be assumed that CERA was also in New York when Hurricane Sandy hit (since the former has been mentioned in the game several times over).

Initial Outbreak
During the first few weeks of the outbreak, CERA was not sent into Manhattan, as it was initially thought that the disease spreading was a more potent version of the flu.

Shortly after however, they were bought in New York when hospitals and clinics became overwhelmed with patients and state relief efforts were under the risk of failing.

During the First Wave
When the First Wave of Division agents was deployed, CERA was in charge of all field hospitals, treatment centers, Safe Houses, supervised the construction of the Dark Zone, and was the organization that dug up the mass graves to bury the bodies. They also employed volunteers to help them ration out food and supplies to civilians in need. Vehicles (from cars to transport CERA officials to shipping eight-wheeler trucks) can be found all over the New York City and were used to adequately deliver much-needed supplies.

However, food, medical, and personnel shortages led to increased riots, to the point where the Joint Task Force (who were in charge of protecting these supplies and personnel) couldn't handle it. After the major disaster of the Dark Zone, along with the First Wave Division agents going M.I.A., forced CERA to pull out alongside the JTF, and CERA support from all hospitals and treatment centers ended.

Currently
CERA has been incredibly weakened at this point, with very little manpower. However, despite this lack of manpower, CERA still continues to treat the sick and research for a cure alongside local doctors and nurses, although this research and treatment is limited to those who stay in the Base of Operations and some Safe Houses.

New York Collapse
In New York Collapse (an Interactive novel based on the Survival Guide in game) there is a yellow sign from CERA stating that they'll be in the neighborhood vaccinating everyone against smallpox. This is before CERA lost their grip on supply delivery, and before they discovered that the smallpox strain was heavily mutated, rendering the vaccine useless.

Tom Clancy's The Division 2
Active CERA operations in D.C. most likely ended with the evacuation of the JTF from D.C., or followed shortly afterward. CERA checkpoints, camps, evacuation points and treatment facilities are scattered throughout the city, yet none of these facilities are active due to the complete collapse of security, supplies and communications. CERA, in joint operations with the JTF, also attempted to create quarantines and mass treatment facilities like the Roosevelt Island Quarantine and the Potomac Event Center Treatment Facility that were put under control of Colonel Ridgeway and his men, who notoriously abused and starved the sick, believing that they were as good as dead and not worth the resources; Ridgeway and his unit's actions would eventually lead to the rise of the Outcasts. CERA's role in the Washington, D.C. narrative is essentially nonexistent at this point in the game, with the faction's personnel and capabilities having evaporated with the JTF pullout. However, the doctors who work in the health clinics at the various settlements as well as at the Base of Operations are most likely related to or are associated with CERA. It is also implied that CERA is responsible for supplying the JTF in the White House.

In Warlords of New York, CERA's presence in the city has also been dismal, with no active operations being visible to the player. CERA crates, barricades, outposts and trucks can be found throughout the city, like the JTF shelter in Two Bridges and on Liberty Island (used as an evacuation point). It is also inferred that CERA is supplying JTF, Division and civilian installations around the country when acting Division Commander Faye Lau and Captain Roy Benitez talk about CERA shipments and troop counts. Instead of operating as an actual faction, CERA has now taken the role of supplying the JTF and Division with food, water and medicine.

Tom Clancy's The Division
Unlike the JTF, CERA has no role, gameplay-wise. They are mostly a background faction, usually requesting agents to collect data during Encounters, and play a bigger role than usual during the mission Hudson Refugee Camp, where both CERA and JTF doctors and soldiers who are first aid-certified arrive on the scene to take blood samples from the survivors.

CERA workers can be found in the Base of Operations (usually in the Medical Wing) treating sick or wounded JTF soldiers and/or civilians, and can be found in a few safe houses.

Tom Clancy's The Division 2
By this time, CERA is a shadow faction - it is known that they were in D.C., there are no indicators that they are still operating fully in the city. It is widely assumed that medics and workers have either merged in with the JTF and work in the Sick Bay, left when the bulk force of the JTF pulled out of the city, or were violently murdered by the hostile factions in the city.

Real Life Counterpart
The real-life counterpart of CERA is FEMA (Federal Emergency Management Agency), as both are federal agencies that are dispatched when local and state relief efforts have failed or been overwhelmed from natural disasters. Their logos are also similar when compared.

Trivia
CERA Центр экстренного реагирования и аналитики
 * If agents pay attention to notice signs and banners put up by CERA, they will see a line at the bottom of said signs and banners referring to a law called "Quarantine Act of 1908".
 * However, there is no such law active in the United States. The actual U.S. law being called the "National Quarantine Act", which gives the federal government the power to set up and enforce quarantine procedures.
 * Tom Clancy's The Division references the "Quarantine Act 1908" which was actually an Australian law. However, that has since been replaced with the "Biosecurity Act 2015".