Brazil’s health regulator has suspended trials of a Chinese-developed COVID-19 vaccine following a “serious adverse event” involving a volunteer recipient, according to sources cited by CNN’s affiliate, CNN Brasil.
Chinese drugmaker Sinovac Biotech began Phase 3 trials of its CoronaVac in collaboration with the Brazilian Butantan Institute in Sao Paulo in late July, with an aim to recruit 130,000 volunteers. Phase 3 trials represent the final and most important testing stage before regulatory approval is sought.
The pause in testing marks a potential setback for one of China’s leading vaccine candidates and comes as US drugmaker Pfizer said Monday that early data from its own coronavirus vaccine showed more than 90 percent effectiveness.
According to a note from Brazil’s National Health Surveillance Agency, an incident reported on October 29 led to a decision to suspend the trial in order to better evaluate the data and assess the risk.
“With the study interrupted, no new volunteers can be vaccinated,” read the note published by CNN Brasil late on Monday, local time.
The note did not elaborate on the specific nature of the serious event or where it took place, citing privacy concerns. The Butantan Institute said it would hold a press conference Tuesday morning local time, according to CNN Brasil.
In a statement posted online on Tuesday, Sinovac said it was “confident in the safety of the vaccine,” without giving a reason for the reported suspension.
“We have communicated with our Brazilian partner, the Butantan Institute, and the head of the institute believes the incident has nothing to do with the vaccine. Sinovac will continue to communicate with the Brazilian side on this matter. Work related to our clinical research in Brazil will continue to be carried out in strict accordance with GCP (Good Clinical Practice) requirements,” the statement said.
A Chinese Foreign Ministry spokesman read the company’s statement to reporters when asked to comment on the development at the ministry’s daily press briefing on Tuesday.
Pausing a clinical trial is not unusual. In September, drug giant AstraZeneca paused global trials of its coronavirus vaccine because of an unexplained illness in one of the volunteers.
Last month, Sao Paulo Governor Joao Doria had called CoronaVac “the safest, the one with the best and most promising rates” among all the vaccines tested in Brazil, after Butantan Institute said that the vaccine had proved to be safe in a trial involving 9000 volunteers, according to Reuters.
Sinovac is also conducting Phase 3 trials in Indonesia and Turkey. Sinovac did not immediately responded to CNN’s request for further comment.
Just last month, Chinese officials and vaccine developers declared that no serious side effects had been observed or reported in the clinical trials of any of China’s rapidly produced vaccines. China currently has four coronavirus vaccines in Phase 3 clinical trials, mostly conducted in developing countries across the world.
An official with China’s Ministry of Technology said at a press conference on October 20 that a total of 60,000 participants had been injected with the four Chinese vaccines in Phase 3 trials — and no serious adverse effects had been reported.
Sinovac General Manager Gao Qiang said at the same event that while some mild adverse effects had been detected in its Phase 3 trials, no serious reactions had been reported in Brazil, Indonesia or Turkey. He said its collaborators in the three countries had established a “thorough detection system for adverse effects.”
Vaccines, like any medicine, may cause side effects, but most are usually minor and short-lived, such as pain, rashes, headaches or fever.
It is unclear if Brazil’s suspension of the Sinovac trials will have any impact on the company’s ongoing trials in Indonesia and Turkey.
Last week, Indonesia said it planned to vaccinate 9 million people with Sinovac’s CoronaVac in the third week of December, under an Emergency Use Authorisation approval from the country’s drug regulator.
CNN has reached out to Indonesian and Turkish health authorities for comment in light of the decision to pause testing in Brazil.
In China, drug makers have been administering experimental vaccines on tens of thousands of people since July under a government-approved emergency uses program, which allows vaccine candidates to be used on a limited scale before their safety and efficacy have been fully proven by clinical trials.
The move is controversial as some experts worry that fast-tracking the normal approval process could potentially expose participants to unknown side effects, and Chinese drug makers are taking risks that contravene international ethical and safety norms.
Jair Bolsonaro claims ‘victory’ after suspension of Chinese vaccine trial
The Brazilian president, Jair Bolsonaro, has sparked outrage by gloating over the suspension of clinical trials of the Chinese coronavirus vaccine after a volunteer’s death.
“Another victory for Jair Bolsonaro,” read a comment posted by the official Facebook account of Brazil’s far-right leader on Monday night after the country’s health regulator, Anvisa, announced it had halted testing of the CoronaVac jab.
Anvisa said the trial of the vaccine – which is being developed by the Chinese biopharmaceutical firm Sinovac Biotech – had been suspended as a result of a “adverse, serious event” involving a participant in Brazil.
But many Bolsonaro critics see a possible political motivation behind the move, and the head of the Brazilian research centre coordinating the trial claimed the volunteer’s death was not related to the vaccine.
The broadcaster TV Cultura reported on Tuesday that the “event” was suicide, saying it had seen the coroner’s report showing the trial volunteer had taken their own life.
The CoronaVac is being developed in partnership with the São Paulo-based research centre Butantan and has been championed by São Paulo’s state governor, João Doria, who is one of Bolsonaro’s biggest political foes.
That rivalry has placed the CoronaVac at the centre of a growing political brawl with Doria, who many believe will challenge Bolsonaro for the presidency in 2022, who promised to implement a compulsory vaccination scheme in his state while the president opposed such a move.
On Monday night Bolsonaro wrote on Facebook: “This is the vaccine Doria wanted to force everyone in São Paulo to take. Another victory for Jair Bolsonaro.”
Those comments caused immediate anger. “163,000 dead in Brazil. And Bolsonaro says he’s won,” tweeted Flávio Dino, the leftwing governor of Maranhão state and one of the key figures in Brazil’s opposition.
Speaking on Tuesday morning Dino said Bolsonaro’s “bizarre, irresponsible and ridiculous” remarks reflected the president’s ideological opposition to China and its Communist party leaders as well as his “personal hatred” of Doria.
“Once more Bolsonaro has shown that he’s not worried about the lives and wellbeing of the population but simply his own ideological interests … Bolsonaro treats everything as an ideological war,” Dino, who is also seen as a potential leftwing challenger for the presidency, told the Guardian.
Ciro Gomes, another prominent leftist leader, tweeted: “Prison’s not enough for scumbags who play politics with a vaccine, the only way of bringing an end to the greatest public health and socioeconomic crisis in history.”
While vaccine trials are often halted to investigate suspected side-effects, including the phase 3 trial of the British Oxford University/AstraZeneca vaccine, the language used by the Brazilian authorities was unusually strong although they provided no additional details except that the adverse event took place in late October.
Clouding the issue were comments from Dimas Covas, Butantan’s director, who told Brazilian TV that the volunteer’s death was not due to the vaccine. “We found this … decision strange, because it is unrelated to the vaccine. There are more than 10,000 volunteers at this moment,” he added.
The decision to halt the programme comes just days before the first large batch of 120,000 CoronaVac shots are due to arrive in Brazil on 20 November. The rollout is now likely to be delayed.
CoronaVac shot has been embroiled in political controversy in Brazil, where Bolsonaro, who has a history of minimising the threat of coronavirus, has cast doubt on its prospective effectiveness.
He sparked confusion last month when he publicly rejected it, saying Brazilians would not be used as guinea pigs.
Bolsonaro has often expressed mistrust of China, particularly on the campaign trail in 2018, although he has softened his rhetoric somewhat in office.
Coming hard on the heels of the disclosure yesterday that the German BioNTech/Pfizer vaccine had demonstrated 90% effectiveness in its interim results, the Brazilian announcement marked the latest stumble in a global stop-start progress being watched anxiously around the world.
Critics have expressed concern about what has sometimes appeared an unseemly and occasionally unethical race to get vaccines approved for use.
With 170 teams working on different vaccines around the world, huge capital – including political – has been invested in getting the first successful vaccines to the market.
The Chinese government’s approach to vaccines has become controversial after it had been revealed that hundreds of thousands of Chinese had already taken experimental Covid-19 vaccines as part of a state initiative to protect frontline health workers and officials travelling to high-risk nations.
Critics have long warned that failure to follow proper international testing and safety protocols for potential Covid-19 vaccines risk undermining public trust and could increase public resistance to inoculation.
Another Chinese vaccine candidate, produced by Sinopharm’s China National Biotec Group (CNBG) is currently in phase 3 trials in more than 10 countries, including the UAE, where it has been granted emergency use authorisation after the country’s own testing.
The UAE has also been used to recruit volunteers for Russian vaccine candidates, where similar anxieties have been expressed about two Russian vaccines that were given hasty regulatory approval despite not having completed full phase 3 testing.
The Russian vaccine Sputnik V – developed by the Gamaleya Research Institute in Moscow – was given the green light by Ministry of Health of the Russian Federation in August, while a second vaccine in Russia, EpiVacCorona, was also approved without entering phase 3 clinical trials.
The Russian president, Vladimir Putin, said on Tuesday that all Russian vaccines against Covid-19 were effective, adding that the country would soon register a third shot against the virus.
Source: The Guardian