Efficacy of vaccines may reduce after mass inoculation – Dr. Yong

 

 

The efficacy of any vaccine, including COVID-19 vaccines, tends to be lower when used in the field to inoculate millions of people, when compared to the results produced during clinical trials, said Thai virologist Dr. Yong Poovorawan in his Facebook post on Friday.

 

He cited the case of a Hepatitis B vaccine, which its manufacturer claimed had efficacy of between 94-95%. When the vaccine was used in mass inoculations, however, its efficacy dropped to about 80%.

 

Likewise, he said, the 95% efficacy of a COVID-19 vaccine, asclaimed by Pfizer during the trial period, is likely to drop due to several variables.

 

Full story: https://www.thaipbsworld.com/efficacy-of-vaccines-may-reduce-after-mass-inoculation-dr-yong/

 

 

-- © Copyright Thai PBS 2021-01-22

 

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Pure speculation, some of these vaccines are based on a new generation of technology.

As I understand the Chinese vaccine Sinovac (which is still to be peer reviewed) has 50.4% efficacy so any significant drop would put them under the 50% cut off required by the WHO.

Just get the bloody vaccines out and into arms now Dr. Yong. Never mind wracking your brains to come up with hypothetical negatives. 

He never disappoints me. It's Saturday and he is back. What a lovely man.

2 hours ago, Deli said:

He never disappoints me. It's Saturday and he is back. What a lovely man.

We are so glad that here on TVF we have real experts

As an arguer for doing nothing this man takes the biscuit. Just get on with it!!!

The Title (which is from PBS and not created by TVF!) is misleading as it gives the impression that he is talking about  actual vaccine effectiveness changing, for example the virus mutating into a less susceptible form.

 

. Instead what he refers to is the possibility that the actual real-life efficacy will prove lower once it has been administered on a mass level compared to what was seen in the trials.

 

in clinical trials, protocols are meticulously followed - no mistakes in administration of the vaccine (vaccine reconstituted with exactly the recommended type and amount of solvent, exact amount given exactly as recommend) , no varying from the recommended schedule.

 

In real life, clinicians sometimes make small mistakes - vaccine out of the fridge a little too  long, slightly too much dilutent used to reconstitute, slightly less than recommended dose drawn up, or injected sc rather than IM (easily happens with obese clients) etc. And it is not always possible to provide the 2nd does at exactly the recommended time...vaccine stocks might nto arrive in time or client may not be able to make the apppinttment, etc etc.

 

So what you see in a clinical trial is the effectiveness under ideal conditions. And then what you see after mass administration is effectiveness under real world conditions.

 

True for everything not just COVID vaccines.

21 hours ago, webfact said:

Likewise, he said, the 95% efficacy of a COVID-19 vaccine, asclaimed by Pfizer during the trial period, is likely to drop due to several variables.

 

And what about that Chinese vaccine that Thailand has already bought which is just barely over 50 percent before "variables?" If the Pfizer drops from 95 pecent to 80 percent, does that mean the Chinese will drop from 50 percent to 35 percent. If so, that seems pretty useless.

16 minutes ago, John Drake said:

 

And what about that Chinese vaccine that Thailand has already bought which is just barely over 50 percent before "variables?" If the Pfizer drops from 95 pecent to 80 percent, does that mean the Chinese will drop from 50 percent to 35 percent. If so, that seems pretty useless.

 

 

I think it means he is trying to justify the low quality <deleted> Thailand just bought millions of doses of, while the world market has better vaccines available.

 

 

1 hour ago, Sheryl said:

"And then what you see after mass administration is effectiveness under real world conditions."

But no indications at all so far that Thailand is even contemplating mass administration.

1 hour ago, Sheryl said:

in clinical trials, protocols are meticulously followed - no mistakes in administration of the vaccine (vaccine reconstituted with exactly the recommended type and amount of solvent, exact amount given exactly as recommend) , no varying from the recommended schedule.

You mean like the dosage stuff up by Astra Zeneca during trials?

2 hours ago, FarFlungFalang said:

You mean like the dosage stuff up by Astra Zeneca during trials?

People make mistakes, that's life.

2 minutes ago, ukrules said:

People make mistakes, that's life.

Yes they do and in this case it was fortunate that this mistake led to the discovery that was an increase in the efficacy.

Dr google is knowledge on legs as the zero% inoculated rollout continues ???? 

2 hours ago, FarFlungFalang said:

You mean like the dosage stuff up by Astra Zeneca during trials?

You mean the dosage "stuff up" that showed that if you gave a different dosage in the initial shot, you could vastly improve the effectiveness of the vaccine? Yes, it is called serendipithy. As in life, science is full of it. Isn't it wonderful?

26 minutes ago, Proboscis said:

You mean the dosage "stuff up" that showed that if you gave a different dosage in the initial shot, you could vastly improve the effectiveness of the vaccine? Yes, it is called serendipithy. As in life, science is full of it. Isn't it wonderful?

That's what happened in this case and you might call it serendipity but had the mistake caused harm to many we would call it stupidity instead then it would not be wonderful,which is why we don't normally rush vaccine approvals as in this case.Wonderful to rely on dumb luck?

On 1/22/2021 at 9:26 PM, FarFlungFalang said:

As I understand the Chinese vaccine Sinovac (which is still to be peer reviewed) has 50.4% efficacy so any significant drop would put them under the 50% cut off required by the WHO.

whatever who require is not relevant because they lie about most things...if china says its 50%, it probably doesnt work at all... like so much china exports!!!

We just have to wait and see what happens after tons of people has been vaccinated.

Hopefully it wont mutate to much before that, and we're still able to bring it under control. 

 

If Manaus in Brazil is what we should expect to see in the future it's depressive. They thought they had herd immunity last year, but are having a major outbreak once again and people are getting sick a second time. 

 

https://science.sciencemag.org/content/371/6527/329?utm_campaign=toc_sci-mag_2021-01-21&et_rid=714521026&et_cid=3638463

 

I cross my fingers the vaccines do the trick and at least the mRNA vaccines are fast to reprogram to new mutations compared to the old school type vaccines. 

 

If this continues for years to come I need drugs for depression.... 

The one nice thing is that the rich expats could maybe get a trip to their home countries

and get some other form of vaccine. Right?  The Thailand population except for the

very rich who could also go somewhere else for a shot, will get what they will get.  Ain't

life just grand!   I guess the 2 weeks at each end of the trip may be a slight bummer for

the travellers.  Darn.  I will just be happy to get a vaccine, when Canada gets some Moderna

or maybe eventually more Phyzer  product, which may happen some time this coming Summer.

Geezer

22 minutes ago, Stargrazer9889 said:

The one nice thing is that the rich expats could maybe get a trip to their home countries

and get some other form of vaccine. Right?  The Thailand population except for the

very rich who could also go somewhere else for a shot, will get what they will get.  Ain't

life just grand!   I guess the 2 weeks at each end of the trip may be a slight bummer for

the travellers.  Darn.  I will just be happy to get a vaccine, when Canada gets some Moderna

or maybe eventually more Phyzer  product, which may happen some time this coming Summer.

Geezer

Not if the airlines won't let you fly without first having the vaccination like many are contemplating.

3 hours ago, Virt said:

If Manaus in Brazil is what we should expect to see in the future it's depressive. They thought they had herd immunity last year, but are having a major outbreak once again and people are getting sick a second time. 

An interesting comparison is Brazil and Indonesia both countries straddle the equator yet enormous differences in their numbers.I know Brazil has more people living in colder area than Indo but then Japan also has a colder climate yet far fewer deaths.

7 minutes ago, jak2002003 said:

Not if the airlines won't let you fly without first having the vaccination like many are contemplating.

Before airlines go the no vax no fly route it should be established that the vaccines prevent transmission otherwise the spread will continue and the NVNF will achieve nothing.  

3 minutes ago, FarFlungFalang said:

An interesting comparison is Brazil and Indonesia both countries straddle the equator yet enormous differences in their numbers.I know Brazil has more people living in colder area than Indo but then Japan also has a colder climate yet far fewer deaths.

Just need to look at the Brazilian diet to see the defining factor.

17 minutes ago, Sametboy2019 said:

Just need to look at the Brazilian diet to see the defining factor.

Could well be as easy as that, seems to be a lot of obesity and associated health issues there.

27 minutes ago, FarFlungFalang said:

An interesting comparison is Brazil and Indonesia both countries straddle the equator yet enormous differences in their numbers.I know Brazil has more people living in colder area than Indo but then Japan also has a colder climate yet far fewer deaths.

The biggest difference between these countries is that Asia was infected earlier with a much slower spreading 'D' strain. The West was affected from the get go with the much faster  spreading 'G' strain.

5 minutes ago, rabas said:

The biggest difference between these countries is that Asia was infected earlier with a much slower spreading 'D' strain. The West was affected from the get go with the much faster  spreading 'G' strain.

Also so we are still in the middle of this thing so we will have to see how it pans out and see what happens in Asia if/when they get hit with the newer strains. 

1 hour ago, FarFlungFalang said:

Also so we are still in the middle of this thing so we will have to see how it pans out and see what happens in Asia if/when they get hit with the newer strains. 

Yes, we'll see. The strain from Myanmar is a descendent of the early, faster spreading Western 'G' strain that passed through India.

 

Because of the recent rise of even newer mutations, we may be in the middle or even early part of the global pandemic. Now they worry that lower efficacy vaccines and also delaying a second dose could increase mutations because many people would have partial immunity.  A worrisome summary from  AAAS's Science:

 

New mutations raise specter of ‘immune escape’

 

I hope Thailand has second thoughts about relying on the lowest quality vaccines from China.

37 minutes ago, rabas said:

Yes, we'll see. The strain from Myanmar is a descendent of the early, faster spreading Western 'G' strain that passed through India.

 

Because of the recent rise of even newer mutations, we may be in the middle or even early part of the global pandemic. Now they worry that lower efficacy vaccines and also delaying a second dose could increase mutations because many people would have partial immunity.  A worrisome summary from  AAAS's Science:

 

New mutations raise specter of ‘immune escape’

 

I hope Thailand has second thoughts about relying on the lowest quality vaccines from China.

From my sceptical view of "big pharma" I can see them rubbing there hands together at the thought of more profits.

2 hours ago, FarFlungFalang said:

From my sceptical view of "big pharma" I can see them rubbing there hands together at the thought of more profits.

 

I think it gets ugly when drugs are priced way to high and the profit is not reasonable, but so far I'm not seeing that in any of the vaccines prices. 

 

I think all of them are within a very reasonable price range.