Brazil Halts and Re-Starts Phase 3 Clinical Trials of Chinese COVID-19 Vaccine

by Carolyn Hendler, JD

Published November 24, 2020 | Vaccination, Risk & Failure Reports

Brazil briefly stopped clinical trials of CoronaVac, the Chinese-made experimental vaccine for COVID-19, after a death among trial participants was reported on Nov 9, 2020. The Bhutantan Institute in San Paulo, Brazil had been conducting Phase 3 trials with more than 10,000 volunteers when the study was halted.¹ However, within days, Bhutantan officials announced they had concluded the death of the CoronaVac trial participant, reportedly ruled to be a suicide following results of toxicology reports, was not related to the vaccine and that the clinical trials would soon resume.²

The Bhutantan Institute signed an agreement in July 2020 with Sinovac, the Chinese company developing CoronaVac, to conduct clinical trials in Brazil and then locally produce the vaccine once it is licensed by the government. Since then, seven states in Brazil along with the Federal District have been involved in conducting CoronaVac vaccine trials.³

After the death of a CoronaVac vaccine trial participant, Brazil’s National Health Surveillance Agency, Anvisa, had halted the Phase 3 trials in order to evaluate the data and assess the risks the vaccine might pose. The agency had said the CoronaVac clinical trials would resume in Brazil only after an independent international ^{4 5}

Officials Say “No Relation” of Death in Clinical Trials to Coronavac Vaccine

There was some controversy as to whether temporarily suspending the CoronaVac vaccine trials was necessary. While Dimas Covas, MD, Director of Bhutantan Institute, admitted that a volunteer for the vaccine trial had died, he stated that there was no reason to stop the trials because the death was unrelated to the vaccine.^{6 7} “The serious adverse event observed in a volunteer in the trial has no relation to the vaccine,” Covas said. “It was analyzed and determined that there was no relation.”⁸

The New York Times reported the police report of the Oct. 29 death of the CoronaVac vaccine trial volunteer listed the death as a suicide.⁹

The director of pharmaceuticals at Anvisio, Gustavo Mendes, stated that temporarily suspending the CoronaVac clinical trials was “a precautionary measure,” he said. “Unfortunately, it’s being politicized. Halting a study until there is more information is what is expected of a regulatory agency.”¹⁰

Brazil has been divided on which COVID-19 vaccines to endorse with the governor of San Paulo, Joao Doria, backing the Chinese manufactured CoronaVac and the President of Brazil, Jair Bolsonasro, supporting a vaccine manufactured by AstraZeneca and Oxford University.¹¹ After the halting of the CoronaVac vaccine trials by the Brazilian health agency was called a political victory, allegations were made that President Bolsonaro paused the trials because of his hostility towards China.^{12 13}

CoronaVac Vaccine Phase 3 Trials Resumed in Brazil

On Nov. 11, less than two days after it shut down the CoronaVac vaccine trials, Anvisio has allowed the clinical trials to resume alleging that it “has sufficient elements to allow vaccination to resume”.^{14 15} Anvisio announced that it “continues to monitor the investigation of the outcome of the case in order to define the possible causal relationship between the unexpected event and the vaccine.”¹⁶

Phase 3 trials testing CoronaVac vaccine were not discontinued in Indonesia and Turkey, where clinical trials are also taking place with approximately 27,000 people receiving the vaccine.¹⁷

CoronaVac vaccine is one of four Chinese made vaccines that are in phase 3 trials, most of which are being conducted in developing countries.¹⁸ CoronaVac has already been given to a large segment of the population despite the clinical trials not being complete. Chinese officials authorized the use of the CoronaVac vaccine candidate in tens of thousands of people before completion of Phase 3 trials.¹⁹

The New York Times reported, “It is rare for a drug that has not been fully tested to be so widely administered, and scientists from around the world have repeatedly warned that the Chinese government was risking the health of its people before the completion of late-stage trials.”²⁰

Six million doses of CoronaVac have been authorized by Anvisa to be shipped to Brazil from China along with the raw material for Brazil to produce 40 million doses independently.²¹ Officials in Indonesia announced that the country’s drug regulator approved Emergency Use Authorization (EUA) for CoronaVac and there are plans to vaccinate nine million people in the third week of December.²²

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References:

  Anvisio, AstraZeneca, Bhutantan Institute, Brazil, Carolyn Hendler, CoronaVac, COVID-19, Dimas Covas, Emergency Use Authorization, EUA, Gustavo Mendes, Indonesia, Jair Bolsonasro, National Vaccine Information Center, NVIC, Oxford University, Sinovac, The New York Times, The Vaccine Reaction, Turkey