Brazil authorizes efficiency test for AstraZeneca booster shot

Also allowed was a study on drug Proxalutamide

Published in 19/07/2021 - 13:57 By Antônio Claret Guerra - Belo Horizonte

Brazil’s national sanitary regulator Anvisa on Monday (Jul. 19) authorized the conduction of clinical studies to assess the safety, efficiency, and immunogenicity of the third dose of AstraZeneca’s vaccine against COVID-19.

The initial study will be carried out in participants who have already received the two doses of the inoculation, with an interval of four week between administrations, Anvisa noted. The booster shot will be administered 11 to 13 months after the second dose.

Anvisa explains that this is a phase-three study, in which volunteers do not know whether they took a dose of the vaccine or placebo.


“Included will be volunteers aged 18 through 55 who have been highly exposed to infection with the novel coronavirus as health professionals. Pregnant women or people with comorbidities will not be included,” the agency explained in a note.

According to Anvisa, the study, sponsored by AstraZeneca, will be conducted in Brazil alone, in the states of Bahia (1.5 thousand volunteers), Rio de Janeiro (1.5 thousand), Rio Grande do Sul (3 thousand), Rio Grande do Norte (1.5 thousand), and São Paulo (2.5 thousand).

After the research blinding is broken and volunteers discover whether they received the real vaccine or the placebo, all group participants will be invited to take the booster shot.


On Monday, the conduction of a clinical study was also authorized, in order to evaluate the safety and efficiency of medicine Proxalutamide in reducing the viral infection caused by the novel coronavirus and the inflammatory process prompted by COVID-19.

This will be a phase-three study gauging the efficiency and safety of the substance in male outpatients with a slight to moderate state of COVID-19.

The study is sponsored by company Suzhou Kintor Pharmaceuticals, headed in China, and will be carried out in Germany, South Africa, Ukraine, Mexico, the US, and Brazil, where 12 volunteers will take place in Roraima, and 28 in São Paulo.

On Sunday (Jul. 18), President Jair Bolsonaro said he would request studies on the use of the drug in Brazil.

Translation: Fabrício Ferreira -  Edition: Kelly Oliveira / Nira Foster

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