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

[webfact 81,858]

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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[ukrules 21,508]

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

[FarFlungFalang 9,715]

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.

Edited January 22 by FarFlungFalang

[TSF 2,674]

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

[Deli 4,321]

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

[Kiujunn 137]

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

[chilly07 549]

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

[Sheryl 27,726]

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.

[John Drake 1,741]

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.

Edited January 23 by John Drake

[4reaL 1,031]

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.

 

 

[TSF 2,674]

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.

[FarFlungFalang 9,715]

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?

[ukrules 21,508]

2 hours ago, FarFlungFalang said:

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

People make mistakes, that's life.

[FarFlungFalang 9,715]

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.

[sammieuk1 20,660]

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