United States — Centers for Disease Control and Prevention & Merck Group

United States — Centers for Disease Control and Prevention: The CDC continues to recommend the combined MMR vaccine and has debunked Trump's claim. It faces pressure to update its schedule while managing the ongoing measles outbreak.

Merck Group: Merck, the sole U.S. manufacturer of the MMR vaccine, stated it cannot produce separate shots for at least 10 years. The executive order could create regulatory and market uncertainty, though current sales are unaffected.

United States — Centers for Disease Control and Prevention: Its vaccine recommendations are being overridden by the executive order, creating confusion. The new CDC director faces pressure to implement changes despite scientific opposition.

Merck Group: As a major MMR manufacturer, it faces potential regulatory and market changes. It stated no scientific evidence supports splitting the vaccine, and it may face pressure to develop separate shots.

United States — Centers for Disease Control and Prevention: United States — Centers for Disease Control and Prevention is providing data showing transmission has not peaked, informing response strategies. Its monitoring is essential for tracking the outbreak.

Merck Group: Merck Group is the developer of Ervebo, the only approved Ebola vaccine, which is being deployed in the DRC outbreak. Its role is central, and successful cross-protection could expand its market and reputation.

United States — Centers for Disease Control and Prevention: Launched a response plan with WHO to improve coordination and surveillance across Africa.

Merck Group: Merck Group's Ervebo vaccine is being deployed in the outbreak response, potentially increasing sales. However, its efficacy against the Bundibugyo strain is unproven, and the trial outcome will be critical.

United States — Centers for Disease Control and Prevention: US agency providing clinical guidance on Ebola. Its expertise is relevant.

Merck Group: Manufacturer of RVSV-ZEBOV vaccine, which is being considered for cross-protection trials. Its vaccine could play a role in the response, benefiting its reputation.