Questions about the Astra Zeneca vaccine

[watgate]

Now that Thailand will be getting the astra zeneca vaccine I am wondering if anyone knows why the efficacy as reported was between 62 and 90 % effective. Both Pfizer and Moderna's efficacy is 95% but I realize that due to the extremely cold refrigeration that is needed to preserve the integrity of these vaccines they would not be practical for Thailand. i understand that there was some sort of issue during the testing of the astra zeneca vaccine which might have caused the high variance of efficacy of this vaccine. If anyone knows any of the details of this I would appreciate reading about it. I am hoping that if their was a problem with the initial testing of the astra zeneca vaccine that it was corrected and that the efficacy of the astra zeneca will not have such a high variance in effectiveness in fighting the virus. It would be nice but probably asking for too much for the astra zeneca vaccination to also be in the 95% effectiveness range like Pfizer and Moderna's is.  Lastly I realize, unlike Pfizer and Moderna's vaccinations using new technology in producing their vaccines, Astra Zeneca used the more conventional approach utilizing a dead virus in producing their vaccine.  Does anyone know if the method used by Astra Zeneca is as effective as the new technologies used by Pfizer and Moderna in developing their vaccines Any clarification or  info would be most appreciated.

[TSF]

53 minutes ago, watgate said:

Now that Thailand will be getting the astra zeneca vaccine I am wondering if anyone knows why the efficacy as reported was between 62 and 90 % effective. Both Pfizer and Moderna's efficacy is 95% but I realize that due to the extremely cold refrigeration that is needed to preserve the integrity of these vaccines they would not be practical for Thailand. i understand that there was some sort of issue during the testing of the astra zeneca vaccine which might have caused the high variance of efficacy of this vaccine. If anyone knows any of the details of this I would appreciate reading about it. I am hoping that if their was a problem with the initial testing of the astra zeneca vaccine that it was corrected and that the efficacy of the astra zeneca will not have such a high variance in effectiveness in fighting the virus. It would be nice but probably asking for too much for the astra zeneca vaccination to also be in the 95% effectiveness range like Pfizer and Moderna's is.  Lastly I realize, unlike Pfizer and Moderna's vaccinations using new technology in producing their vaccines, Astra Zeneca used the more conventional approach utilizing a dead virus in producing their vaccine.  Does anyone know if the method used by Astra Zeneca is as effective as the new technologies used by Pfizer and Moderna in developing their vaccines Any clarification or  info would be most appreciated.

The reason is during the trails they tested a couple of different strengths of doses and got different efficacy results. The people who received weaker strength doses showed higher efficacy , so less was more. The AZ seems to be the vaccine that will best benefit mankind...very cheap, easy to store and transport.

[Bender Rodriguez]

you did not see the race of the numbers .... 70 percent, 80, 90, 92, 95,  804 ...

 

vaccine trials use HEALTHY YOUNG PEOPLE

 

not old, sick, chronic patients, that is under EXCLUSIONS of most medications

[cormanr7]

Well, you could read the report on the results of the phase III trials, it is all spelled out there. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)32661-1/fulltext.

But to summarize: the results of the trials (with two full doses) in the UK and Brazil gave 60 and 64% efficacy (here based on positive PCR tests, not number of severe cases). These two trials had roughly similar number of participants, so overall efficacy was 62%. Then additional trial (intended as a single full dose) with an inadvertent half dose followed by full dose after 8-12 weeks (when it was discovered) gave 90% efficacy but had 1) a low number of participants, 2) all aged below 55. Pooling these data (not recommended) resulted in 70%.

The claim that vaccine trials only use healthy young people is rubbish; the age (divided in various ranges) of the participants as well as number with underlying health conditions is also stated in the article. AstraZeneca was criticized however, for including a limited number of elderly people . For the UK trials, the fraction of participants aged over 70 was 9% but in the Brazil trial as low as 0.5%.

[mommysboy]

The Oxford jab, like the others, seems to be highly effective (99%)  at preventing serious illness and death.  From an individual's perspective surely this is the only metric that is important.

 

Actual efficacy is thought to be higher than originally thought (75%) due to a change in dosing strategy,  but the results are as yet unpublished.

 

It appears to be well tolerated.

 

If your concern is avoiding even mild infection then you should aim for one of the mRNA vaccines I guess.

 

Note, the Astrazeneca vaccine relied on regular testing, which may be significant in assessing real efficacy.

 

 

Edited January 9, 2021 by mommysboy

[mommysboy]

On 1/8/2021 at 9:28 AM, Bender Rodriguez said:

you did not see the race of the numbers .... 70 percent, 80, 90, 92, 95,  804 ...

 

vaccine trials use HEALTHY YOUNG PEOPLE

 

not old, sick, chronic patients, that is under EXCLUSIONS of most medications

 

That's not true.  Mostly the first doses are administered to younger, healthier candidates as a safety protocol. After that older participants are also used, as well as those who may have stable underlying health conditions.  This is in the UK anyway. 

 

But it is true that efficacy rates drop in real world conditions as vaccines are then used on very old and sick people, whose basic health is sadly rather poor anyway.  In some localities vaccine spoilage may also be an issue, which is true of all vaccines, but especially the Pfizer one which is incredibly fragile.