By Fabian Cambero

SANTIAGO (Reuters) - Chinese pharmaceutical Sinovac Biotech Ltd on Wednesday said it will build a fill-and-finish vaccine plant in Chile with an investment of $60 million, consolidating its presence in the Latin American nation that has used its COVID-19 shot the most.

Chile has run one of the world's fastest vaccination campaigns, so far fully vaccinating more than 60% of its population, including with 19.6 million doses of Sinovac's CoronaVac already delivered.

The plant will be built in the Santiago region in the first quarter of 2022. Sinovac will also build a research and development center in the northern region of Antofagasta.

Since mid-July, Sinovac executives have been looking at the possibility of building a plant in Chile with a capacity to produce 50 million vaccines of diverse types.

The Chilean government bet big on Sinovac's COVID-19 vaccine, part-funding along with local businesses CoronaVac's trial in the country, and ordering 60 million doses of the drug over the next three years, later topping up with more orders.

The health ministry has also indicated it will consider issuing third doses of vaccines to bolster their effectiveness in the face of new variants such as the Delta strain presently nudging up infection rates around the world.

Data released by the Chilean government on Tuesday suggested CoronaVac's effectiveness at preventing symptomatic infection among its recipients fell from 67% when measured between February and April, to 58.5% when measured again at the start of July.

(Reporting by Fabian Cambero; Editing by Jonathan Oatis and Alistair Bell)