Sinovac's vaccine efficacy less than 60% in Brazil trial -report

 

FILE PHOTO: Brazil's Sao Paulo state Health Secretary Jean Gorinchteyn holds a box of the 'CoronaVac' COVID-19 vaccine, developed by Sinovac Biotech as the plane carrying containers with 5,5 million doses arrives at Viracopos International Airport, in Campinas, Brazil December 24, 2020. REUTERS/Amanda Perobelli

 

SAO PAULO (Reuters) - The coronavirus vaccine developed by China's Sinovac Biotech showed a general efficacy of less than 60% in its late-stage trial in Brazil, a news website reported on Monday, citing two people who seen the results.

 

Sao Paulo's Butantan biomedical center, which partnered with Sinovac to test and produce the vaccine in Brazil, dismissed the report as "purely speculative" as it prepares to release a more complete set of results on Tuesday at 12:45 p.m. (1545 GMT).

 

Medical experts and regulators criticized what they called an incomplete disclosure of study results last week.

 

Dimas Covas, director of the Butantan biomedical center, which is running a late-stage trial of the vaccine in Brazil, said ongoing analysis had yielded a new "general efficacy" rate in addition to the "clinical efficacy" announced last week.

 

On Thursday, Brazilian researchers said the vaccine was shown to be 78% effective against mild cases of COVID-19 and entirely prevented severe cases. But independent specialists called for more transparency on the findings from the Phase III trial of the Sinovac vaccine, known as CoronaVac.

 

Indonesia gave the vaccine emergency use approval on Monday based on interim data showing it is 65% effective.

 

Brazilian news website UOL reported that the efficacy rate that Butantan was set to announce on Tuesday was between 50% and 60% — above the threshold set by health regulators, but well below the numbers celebrated last week.

 

Both the Chinese vaccine and a shot developed by Oxford University and British-Swedish firm AstraZeneca Plc have requests for emergency use authorization pending with regulators in Brazil, which has lost more than 200,000 lives to the pandemic – the worst death toll outside the United States.

 

Piecemeal disclosure of results from global CoronaVac studies have contributed to concerns that vaccines developed by Chinese producers are not subject to the same public scrutiny as U.S. and European alternatives.

 

In an interview with news website UOL on Monday, Covas said Butantan, which is funded by Sao Paulo state, had prioritized getting its data to Brazilian health regulator Anvisa and was still analyzing the results in parallel.

 

Covas said the institute would eventually provide its full data to a scientific conference to be announced this week.

 

Anvisa said on Saturday that a filing from Butantan seeking emergency use authorization for CoronaVac lacked some relevant information for analysis of the study, such as the age, gender and comorbidities of volunteers.

 

Covas said the federal agency's handling of the CoronaVac trial had raised questions about its independence, adding to tensions between Sao Paulo officials and the government of President Jair Bolsonaro, who had spurned the Chinese vaccine.

 

(Reporting by Eduardo Simoes; Additional reporting by Anthony Boadle; Editing by Brad Haynes, Jane Merriman, Paul Simao and Jonathan Oatis)

 

-- © Copyright Reuters 2021-01-12

 

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I guess that 50-60% efficacy is better than nothing!  Isn't this the vaccine that Thailand is getting from China?

Anybody want to buy some snake oil?Does it work?Yes we make lots of money so it works very well.

54 minutes ago, graemeaylward said:

I guess that 50-60% efficacy is better than nothing!  Isn't this the vaccine that Thailand is getting from China?

 

6 hours ago, graemeaylward said:

I guess that 50-60% efficacy is better than nothing!  Isn't this the vaccine that Thailand is getting from China?

the seasonal flu vaccine is only 30-60% effective

2 minutes ago, than said:

the seasonal flu vaccine is only 30-60% effective

Rubbish, I get the flu shot every year and haven't hat the flu as long as I can remember.

14 minutes ago, Meat Pie 47 said:

Rubbish, I get the flu shot every year and haven't hat the flu as long as I can remember.

 

Interim Estimates of 2019–20 Seasonal Influenza Vaccine Effectiveness

https://www.cdc.gov/mmwr/volumes/69/wr/mm6907a1.htm?s_cid=mm6907a1_w

7 hours ago, FarFlungFalang said:

Anybody want to buy some snake oil?Does it work?Yes we make lots of money so it works very well.

Same as the so called bomb detectors! 

7 hours ago, FarFlungFalang said:

Anybody want to buy some snake oil?Does it work?Yes we make lots of money so it works very well.

Thank you for your rigorous analysis of the issues.

1 hour ago, Meat Pie 47 said:

Rubbish, I get the flu shot every year and haven't hat the flu as long as I can remember.

It's true that the flu vaccine is far from 100% effective. But what's also true is that if you do get the flu, your symptoms tend to be a lot less severe if you've already been vaccinated.

As for Sinovac:

As China nears a coronavirus vaccine, bribery cloud hangs over drugmaker Sinovac

Chinese coronavirus-vaccine maker Sinovac Biotech is good at getting its products to market. It was first to begin clinical trials of a SARS vaccine in 2003 and first to bring a swine flu vaccine to consumers in 2009.

Its CEO was also bribing China’s drug regulator for vaccine approvals during that time, court records show.

https://www.washingtonpost.com/world/asia_pacific/coronavirus-vaccine-china-bribery-sinovac/2020/12/04/7c09ae68-28c6-11eb-9c21-3cc501d0981f_story.html

Sums up most of the things you get from knock-off China - not as good as you expected

13 minutes ago, placeholder said:

It's true that the flu vaccine is far from 100% effective. But what's also true is that if you do get the flu, your symptoms tend to be a lot less severe if you've already been vaccinated.

How does one determine how severe one's flu symptoms are going to be without a vaccine?One just can't foresee this unless they are god.Are you god?I've and many others have been trying to find you!The only place I found you was in the dictionary!

Just now, FarFlungFalang said:

How does one determine how severe one's flu symptoms are going to be without a vaccine?One just can't foresee this unless they are god.Are you god?I've and many others have been trying to find you!The only place I found you was in the dictionary!

Because of vaccine trials, that's how. By comparing the severity of symptoms of those who aren't vaccinated to those who are.

3 minutes ago, FarFlungFalang said:

How does one determine how severe one's flu symptoms are going to be without a vaccine?One just can't foresee this unless they are god.Are you god?I've and many others have been trying to find you!The only place I found you was in the dictionary!

• • A 2017 study showed that flu vaccination reduced deaths, intensive care unit (ICU) admissions, ICU length of stay, and overall duration of hospitalization among hospitalized flu patients.
  • A 2018 studyexternal icon showed that among adults hospitalized with flu, vaccinated patients were 59 percent less likely to be admitted to the ICU than those who had not been vaccinated. Among adults in the ICU with flu, vaccinated patients on average spent 4 fewer days in the hospital than those who were not vaccinated.

13 minutes ago, RichardColeman said:

Sums up most of the things you get from knock-off China - not as good as you expected

If it's like a lot of other "made in China" products it won't last long and the warranty will be useless.

1 hour ago, FarFlungFalang said:

How does one determine how severe one's flu symptoms are going to be without a vaccine?One just can't foresee this unless they are god.Are you god?I've and many others have been trying to find you!The only place I found you was in the dictionary!

Placebo controlled double blind trials. 

5 hours ago, Meat Pie 47 said:

Rubbish, I get the flu shot every year and haven't hat the flu as long as I can remember.

 

what conclusion can be drawn from a study of one anecdote?

 

i'll add my experience.  i have not had a flu shot in about 45 years, and have not had the flu during that time.

 

what can i conclude?

I doubt many expats will take the Chinese 60% efficacy vaccine—especially if the Moderna and Astro-Zeneca/Pfizer becomes available in LoS.

9 hours ago, Meat Pie 47 said:

Rubbish, I get the flu shot every year and haven't hat the flu as long as I can remember.

Here's an explanation of why above 50% efficacy rate is good enough.

The FDA's cutoff for Covid-19 vaccine effectiveness is 50 percent. What does that mean?
 

Quote

But even if a Covid-19 vaccine is only 50 percent effective, it could make a difference, experts say, pointing out that the flu vaccine effectiveness can vary widely from year to year, anywhere from 20 percent to 60 percent over the last decade, and the shots still offer benefits. When the flu vaccine matches up well with the influenza viruses that are circulating, the shots can reduce illness, hospitalizations and deaths, the CDC says.

In addition to the efficacy rate, another important number is the seroconversion rate. For example, Sinopharm's vaccine trials in UAE was found to have an efficacy rate of 86% and a seroconversion rate of 99%. This 99% seroconversion rate means that 99% will develop antibodies against the virus and so even though some might get the disease, almost everyone would be prevented from getting the moderate or severe forms of the disease. 

China’s Covid vaccine from Sinopharm is 86% effective, UAE says

50-60% would be typical for a vaccine of this sort, and it will likely prevent serious illness just as the others do.  So it will be most welcome providing full trial data can be analyzed.  Certainly a significant world player, alongside AZ, and hopefully the J and J vaccine.

 

The ability to prevent severe disease is the key metric imo, whilst ensuring safety through adopting conventional techniques.

5 hours ago, ChouDoufu said:

 

what conclusion can be drawn from a study of one anecdote?

 

i'll add my experience.  i have not had a flu shot in about 45 years, and have not had the flu during that time.

 

what can i conclude?

 

Now we have 2 anecdotes. 

Wow it's almost a study ????

4 hours ago, ChouDoufu said:

 

what conclusion can be drawn from a study of one anecdote?

 

i'll add my experience.  i have not had a flu shot in about 45 years, and have not had the flu during that time.

 

what can i conclude?

LOL, you have funny point.

Some may look at the way the efficacy rate of a vaccine is calculated and arrive at a funny conclusion like yours too. For example, to calculate the efficacy rate of Pfizer's mRNA vaccine, 170 participants must be found to be infected. Out of this 170, 8 was from the vaccine group and 162 was from placebo group. The total number of participants of both groups were 22,000 each.

% infected, vaccine group = 8/22000=0.0363%
% infected, placebo group = 162/22000=0.736%
Efficacy rate = 1 - (0.0363/0.736) = 95.1%

Some might say - Hey, 99.264% of those who took the placebo did not get infected!

Of course that's not correct. But it is impractical to wait for at least 11,000 placebo takers to get infected, so we have to take a snapshot to determine the efficacy rate. Unless we purposely infect the participants with the virus, we have make do with this imperfect method to determine the efficacy rate, which may be very different from the real effective rate after full roll-out.

3 minutes ago, Virt said:

 

Now we have 2 anecdotes. 

Wow it's almost a study ????

Take 2 anecdotes with a glass of water and call me in the morning if symptoms persist.

8 minutes ago, Selatan said:

LOL, you have funny point.

Some may look at the way the efficacy rate of a vaccine is calculated and arrive at a funny conclusion like yours too. For example, to calculate the efficacy rate of Pfizer's mRNA vaccine, 170 participants must be found to be infected. Out of this 170, 8 was from the vaccine group and 162 was from placebo group. The total number of participants of both groups were 22,000 each.

% infected, vaccine group = 8/22000=0.0363%
% infected, placebo group = 162/22000=0.736%
Efficacy rate = 1 - (0.0363/0.736) = 95.1%

Some might say - Hey, 99.264% of those who took the placebo did not get infected!

Of course that's not correct. But it is impractical to wait for at least 11,000 placebo takers to get infected, so we have to take a snapshot to determine the efficacy rate. Unless we purposely infect the participants with the virus, we have make do with this imperfect method to determine the efficacy rate, which may be very different from the real effective rate after full roll-out.

 

It's a 95,1 reduction in chance is it not? 

6 minutes ago, Virt said:

 

It's a 95,1 reduction in chance is it not? 

If calculated that way once 170 have been found with symptoms of infections. But I doubt 44,000 are tested every day to see if they have been infected. The problem with this virus is that many may be infected but asymptomatic, so the calculations may not be accurate.

11 hours ago, Meat Pie 47 said:

11 hours ago, than said:

the seasonal flu vaccine is only 30-60% effective

Rubbish, I get the flu shot every year and haven't hat the flu as long as I can remember.

 

I've never had a flu shot and I can't remember the last time I had the flu.  Doesn't prove much...  For that, they'd have to look at thousands of us.

 

 

1 hour ago, Selatan said:

LOL, you have funny point.

Some may look at the way the efficacy rate of a vaccine is calculated and arrive at a funny conclusion like yours too. For example, to calculate the efficacy rate of Pfizer's mRNA vaccine, 170 participants must be found to be infected. Out of this 170, 8 was from the vaccine group and 162 was from placebo group. The total number of participants of both groups were 22,000 each.

% infected, vaccine group = 8/22000=0.0363%
% infected, placebo group = 162/22000=0.736%
Efficacy rate = 1 - (0.0363/0.736) = 95.1%

Some might say - Hey, 99.264% of those who took the placebo did not get infected!

Of course that's not correct. But it is impractical to wait for at least 11,000 placebo takers to get infected, so we have to take a snapshot to determine the efficacy rate. Unless we purposely infect the participants with the virus, we have make do with this imperfect method to determine the efficacy rate, which may be very different from the real effective rate after full roll-out.

I thought it was the rate of those who manifested symptoms, not those who were infected.

Posts reported and removed.

 

23 hours ago, graemeaylward said:

I guess that 50-60% efficacy is better than nothing!  Isn't this the vaccine that Thailand is getting from China?

This is the first vaccine to arrive. It has a similar effectiveness as a conventional flu vaccine (50%) because it is based on an inactivated COVID-19 Virion. A year ago they were hoping for a vaccine that was 50% effective but the new Mrna Vaccines are >95% effective. Thailand will be manufacturing the AstraZeneca Mrna vaccine here soon, the Chinese vaccine is a stop gap measure. The AstraZeneca vaccine other vaccines will be arriving later.