Chile and Costa Rica will begin a rollout of coronavirus vaccinations on Thursday, joining Mexico among the first Latin American countries to begin mass immunization campaigns.
A flight carrying 10,000 vaccines produced by Pfizer/BioNTech arrived at Santiago airport in the Chilean capital on Thursday morning.
Vaccinations of high-priority health workers from four Chilean regions are set to begin on the same day.
Chilean President Sebastian Pinera said the country has secured 30 million coronavirus vaccines from three suppliers, enough to inoculate 15 million people -- over two-thirds of the population -- in the first half of 2021.
Costa Rica received its first shipment of Pfizer-BioNTech vaccines late Wednesday.
"Tomorrow the first Costa Ricans will be vaccinated," President Carlos Alvarado said at a news conference.
"It may be the beginning of the end of this pandemic," he added.
The Costa Rican leader was at Juan Santamaria airport in the capital San Jose to greet a flight delivering the first 9,750 doses of the vaccine, which arrived at 9:00 pm (0300 GMT on Thursday).
Costa Rica last week announced it had approved the vaccine, with health workers and the elderly now expected to be the first to receive jabs.
The country of about five million people had recorded more than 160,000 coronavirus cases as of Wednesday, with 2,065 deaths.
Like many others in the region, its health system has been placed under severe strain by the number of infections.
Particularly hard-hit have been Brazil and Mexico, which became the first Latin American country to receive the Pfizer/BioNTech vaccine on Wednesday.
The Central American country has the world's fourth highest Covid-19 fatality toll after the United States, Brazil and India.
Elsewhere in Latin America, Argentina is due to receive 25 million doses of Russia's controversial Sputnik V vaccine on Thursday.