SÃO PAULO—Brazil, a major customer of China’s CoronaVac shot and a poster boy or girl for Beijing’s endeavours at vaccine diplomacy, is producing a fast retreat from the Covid-19 vaccine as fears grow in excess of its efficacy against the Delta variant and other vaccines grow to be more readily obtainable.

Brazil’s federal governing administration has halted negotiations in excess of additional doses of Sinovac’s vaccine, CoronaVac, spokespeople for the governing administration and its local producer, the Butantan Institute, informed The Wall Avenue Journal. The governing administration has also reported it will not endorse use of CoronaVac for a third booster shot.