Nipah virus, which has a high fatality rate, is a top target for countermeasure development.
The first dose was given in Abidjan, and the rollout will target 38 districts across the country.
Sixty-eight imported malaria cases were identified in Pima, Arizona; San Diego, California; and El Paso, Texas, compared with 28 cases in 2022.
The monoclonal antibody, L9LS, was previously shown to offer 80% protection to adults in a phase 1 trial.
Researchers estimate that 85 pathogens accounted for 704 million disability-adjusted life years globally in 2019.
Vector-borne illnesses have doubled over the past two decades, as the number of pathogens grows and affected areas expand.
Vaccine effectiveness at 1 year was 75% at seasonal sites and 68% at standard sites for time to first malaria infection.
The first patients to receive the vaccine were a pair of twin babies.
In November, Cameroon said it would receive 331,200 doses of the RTS,S vaccine, which is produced by GSK.
The step clears the way for a broader rollout of R21/Matrix-M, which the WHO recommended in October.
