Skip to main content

China's Covid-19 vaccine is only 50% effective - far lower than the 78% originally touted - results from Brazil show

China's Covid vaccine is only 50.4 per cent effective, Brazilian researchers have found, just days after they announced results of 78 per cent from their late-stage trials.

The Brazilian Butantan biomedical centre announced last week the Sinovac Biotech jab had proved 78.4 per cent effective against 'mild to severe' cases which required treatment.

But it has now been revealed their results did not include 'very mild' infections from those who had received the vaccine but did not need medical assistance.

With this data included, the success rate has now dropped to 50.4 per cent, barely sufficient for the 50 per cent minimum for regulatory approval.

It is also well below the 70 per cent recommended by the Chinese government and the World Health Organisation.

The news is a major disappointment for Brazil, as the Chinese vaccine is one of two that the federal government had lined up to administer during their deadly Covid surge.

Sinovac's chairman has insisted the vaccine is highly effective and prevents 100 per cent of severe Covid cases. 

China's Covid vaccine was only 50.4 per cent effective at preventing symptomatic infections in a Brazilian trial

China's Covid vaccine was only 50.4 per cent effective at preventing symptomatic infections in a Brazilian trial

Many have criticised the Butantan biomedical centre for releasing partial data just days ago that generated unrealistic expectations. 

The results came from a trial of 13,000 people in Brazil in the most advanced final phase of testing. 

The trial saw 220 people infected of which 160 were in the placebo group and 60 received the vaccine.

They insisted last week the results were sufficient for 'clinical efficacy' and are insisting the vaccine is still 78 per cent effective in preventing mild cases that would need treatment. 

It is still not clear how the efficacy rate was calculated by the Brazilian officials and a detailed breakdown of the study, showing age groups and side effects, has not been published. 

The confusion may add to skepticism in Brazil about the Chinese vaccine, which President Jair Bolsonaro has criticized, questioning its 'origins.'

Many have criticised the Butantan biomedical center for releasing partial data just days ago that generated unrealistic expectations

Many have criticised the Butantan biomedical center for releasing partial data just days ago that generated unrealistic expectations

'We have a good vaccine. Not the best vaccine in the world. Not the ideal vaccine,' said microbiologist Natalia Pasternak, criticizing Butantan's triumphant tone.

Ricardo Palacios, medical director for clinical research at Butantan, said on Tuesday that the new lower efficacy finding included data on those 'very mild' cases.

'We need better communicators,' said Gonzalo Vecina Neto, a professor of public health at the University of Sao Paulo and former head of Brazilian health regulator Anvisa.

Sinovac chairman Yin Weidong said on Wednesday: 'This data shows that the vaccines have good efficacy and safety in all the phase 3 clinical trials. We have accelerated the ramping up of production capacity.'

He added that the jab was 100 per cent effective at preventing severe cases, 78 per cent effective against cases requiring treatment and 50 per cent effective at 'protecting medical workers'.   

Weidong also cited figures from other trials which showed a much higher efficacy rate.  

Piecemeal disclosures about Chinese vaccine trials globally have raised concerns that they are not subject to the same public scrutiny as US and European alternatives.

Palacios and officials in the Sao Paulo state government, which funds Butantan, emphasized the good news that none of the volunteers inoculated with CoronaVac had to be hospitalized with COVID-19 symptoms.

Public health experts said that alone will be a relief for Brazilian hospitals that are buckling under the strain of surging case loads. However, it will take longer to curb the pandemic with a vaccine that allows so many mild cases.

The news is a major disappointment for Brazil, as the Chinese vaccine is one of two that the federal government had lined up to administer

The news is a major disappointment for Brazil, as the Chinese vaccine is one of two that the federal government had lined up to administer

'It's a vaccine that will start the process of overcoming the pandemic,' Pasternak said.

Sinovac uses an inactivated version of the virus to stimulate the body's immune response.

One major advantage is that it can be stored at refrigerator temperature, making them easy to distribute to the developing world.  

China has already administered 4.5million of the jabs to its citizens as part of its plan to vaccinate 50million people by early February. 

Researchers at Butantan delayed announcement of their results three times, blaming a confidentiality clause in a contract with Sinovac.

In the meantime, Turkish researchers said last month that CoronaVac was 91.25 per cent effective based on an interim analysis. Indonesia gave the vaccine emergency use approval on Monday based on interim data showing it is 65 per cent effective.

Butantan officials said the design of the Brazilian study, focusing on frontline health workers during a severe outbreak in Brazil and including elderly volunteers, made it impossible to compare the results directly with other trials or vaccines.

Still, Covid-19 vaccines in use from Pfizer Inc with partner BioNTech SE and Moderna Inc proved to be about 95 per cent effective in preventing illness in their pivotal late-state trials.

The disappointing CoronaVac data is the latest setback for vaccination efforts in Brazil, where more than 200,000 people have died since the outbreak began - the worst death toll outside the United States.

Brazil's national immunisation programme currently relies on CoronaVac and the vaccine developed by Oxford University and AstraZeneca Plc - neither of which has received regulatory approval in Brazil.

Anvisa, which has stipulated an efficacy rate of at least 50 per cent for vaccines in the pandemic, has already pressed Butantan for more details of its study, after it filed for emergency use authorization on Friday.

The regulator said it will meet on Sunday to decide on emergency use requests for CoronaVac and the British vaccine.

AstraZeneca failed to deliver active ingredients to Brazil over the weekend, leaving the government scrambling to import finished doses of the vaccine from India to begin inoculations.

Popular posts from this blog

Study Abroad USA, College of Charleston, Popular Courses, Alumni

Thinking for Study Abroad USA. School of Charleston, the wonderful grounds is situated in the actual middle of a verifiable city - Charleston. Get snatched up by the wonderful and customary engineering, beautiful pathways, or look at the advanced steel and glass building which houses the School of Business. The grounds additionally gives students simple admittance to a few major tech organizations like Amazon's CreateSpace, Google, TwitPic, and so on. The school offers students nearby as well as off-grounds convenience going from completely outfitted home lobbies to memorable homes. It is prepared to offer different types of assistance and facilities like clubs, associations, sporting exercises, support administrations, etc. To put it plainly, the school grounds is rising with energy and there will never be a dull second for students at the College of Charleston. Concentrate on Abroad USA is improving and remunerating for your future. The energetic grounds likewise houses various

Best MBA Online Colleges in the USA

“Opportunities never open, instead we create them for us”. Beginning with this amazing saying, let’s unbox today’s knowledge. Love Business and marketing? Want to make a high-paid career in business administration? Well, if yes, then mate, we have got you something amazing to do!   We all imagine an effortless future with a cozy house and a laptop. Well, well! You can make this happen. Today, with this guide, we will be exploring some of the top-notch online MBA universities and institutes in the USA. Let’s get started! Why learn Online MBA from the USA? Access to More Options This online era has given a second chance to children who want to reflect on their careers while managing their hectic schedules. In this, the internet has played a very crucial in rejuvenating schools, institutes, and colleges to give the best education to students across the globe. Graduating with Less Debt Regular classes from high reputed institutes often charge heavy tuition fees. However onl

Sickening moment maskless 'Karen' COUGHS in the face of grocery store customer, then claims she doesn't have to wear a mask because she 'isn't sick'

A woman was captured on camera following a customer through a supermarket as she coughs on her after claiming she does not need a mask because she is not sick.  Video of the incident, which has garnered hundreds of thousands of views on Twitter alone, allegedly took place in a Su per Saver in Lincoln, Nebraska according to Twitter user @davenewworld_2. In it, an unidentified woman was captured dramatically coughing as she smiles saying 'Excuse me! I'm coming through' in the direction of the customer recording her. Scroll down for video An unidentified woman was captured dramatically coughing as she smiles saying 'Excuse me! I'm coming through' in the direction of a woman recording her A woman was captured on camera following a customer as she coughs on her in a supermarket without a mask on claiming she does not need one because she is not sick @chaiteabugz #karen #covid #karens #karensgonewild #karensalert #masks we were just wearing a mask at the store. ¿ o