Pedro Nicolaci da Costa, a Federal Reserve and economy watcher at Market News International, re-tweeted on Brazilian data reporting a modest 50.4% efficacy for China’s CoronaVac vaccine in preventing the symptomatic infections of Covid-19 in a clinical trial.
The figure, as a result, did not qualify for regulatory approval and was below the rate announced.
This came as a disappointment for Brazil, as CoronaVac was one of the two vaccines lined up for immunisation during the second wave of the Covid-19 outbreak in the country.
Several scientists had protested against the partial data released by the Butantan biomedical centre just days ago, with President Jair Bolsonaro now criticising and questioning the origins of the coronavirus vaccine.
Chinese vaccine trials across the world have been raising significant concerns about not being subject to the same public scrutiny as the US and European alternatives.
Brazil’s national immunisation programme relies on CoronaVac and ChAdOx1 nCoV-2019 vaccine developed by Oxford University and AstraZeneca Plc, neither of which having received regulatory approval in the country.
However, Ricardo Palacios, medical director for clinical research at Butantan, confirmed that none of the volunteers who had been inoculated with CoronaVac had to be hospitalised with Covid symptoms.