SANTIAGO, Aug 5 - Chile will begin administering a booster shot to those already innoculated by Sinovac's COVID- 19 vaccine, President Sebastian Pinera said on Thursday after studies showed initial doses lose some effectiveness after several months.
Chile launched one of the world's fastest mass vaccination campaigns against COVID in February, and has now fully vaccinated more than 60% of its population, mainly with Sinovac CoronaVac.
We have decisively started a reinforcement of the vaccination of those who have already received both doses of the Sinovac vaccine, Pinera said in a televised address.
The country will begin administering an additional dose of Oxford's Astrazeneca vaccine on Aug. 11 with citizens over 55 who received their shots before 31 March.
Chile joins the United States, Germany, France and Israel in giving booster shots, despite a plea by the World Health Organisation to hold off until more people can get their first shot.
Health subsecretary Paula Daza said domestic and international studies suggested boosters would help strengthen immunity, but that Chile had already donated vaccines to its neighbors and would continue to help as needed.
We are always analyzing the recommendations and likely the possibility of cooperating with other countries in Latin America, she said.
The death toll from the pandemic in Chile is 35,806 and there have been about 1.6 million confirmed cases in total.
Data released on Tuesday by the Chilean government indicated 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.