Jump to content

Recommended Posts

Posted

a4d91c36e4cb07477d7e0c09d3fbcc9e_small.jpg

Image: www.clinicaltrialsarena.com

 

To maximize the usefulness of every tool available for the pandemic response, Thailand is exploring the advantages of combining doses of different COVID-19 vaccines. Thus, Thailand began to administer two doses of different COVID-19 vaccines as of July 19. A week earlier though, Dr. Soumya Swaminathan, the WHO’s chief scientist, made a statement concerning risks involved in mixing and matching COVID-19 vaccines. The remark was directed at individuals seeking adventure by mixing and combining COVID-19 vaccines without seeking appropriate medical advice. The chief scientist stressed that public health agencies should be the sole provider of guidance over mix and match regimens. Thailand has done it. Nevertheless, Thai people are still hesitant to embrace the new approach.

 

Typically, if a person requires two doses of a COVID-19 vaccine, he or she gets two of the same vaccine, for example, two AstraZeneca shots or two Sinovac shots. Not one and then the other. Yet, the notion of combining two different vaccines is not new. This process is referred to as heterologous vaccination or "mix-and-match," in which the first vaccine is delivered initially, followed by a second vaccine of a different kind several weeks later.

 

When individuals hear of changes, it is normal for them to feel concerned. Hence, vaccine skepticism is natural in the context of a new vaccine. However, it should be noted that, despite the novelty of the COVID-19 vaccine, heterologous vaccination is not unusual. Immunologists have previously mixed vaccines against a variety of diseases, including HIV, Ebola, Malaria, and Influenza. In the case of HIV, researchers have long explored this approach because protecting against the virus requires a complex immune response, which is nearly impossible to achieve with a single type of vaccine. One type of vaccine typically elicits only one type of immune response or stimulates only one set of immune cells. Until now, the most effective HIV vaccine has been created using a mix of various vaccine types. In the instance of COVID-19, the mix-and-match strategy most likely started after the AstraZeneca vaccine was connected to extremely rare blood clots. As a consequence, many European nations, including Germany and France, advised that patients who had it as a first dose, should get a second dose of Pfizer or Moderna.

 

All COVID-19 vaccines have received emergency authorization. This implies that there is no data on the efficacy of mixed COVID-19 vaccines. On that account, Thailand’s public health authorities have paid close attention to their ability to enhance immunity and any possible adverse side effects. The combination must be safe, and the advantages must significantly exceed any possible safety issues. Although combining COVID-19 vaccines is an idea that has not been officially recognized globally, some evidence indicates that having two distinct vaccines is better than having only one type of vaccine, since two distinct vaccines may widen or enhance the immune response. In a nutshell, different vaccine platforms activate the immune system in different ways. Apart from the potential benefit to the immune system, mixing vaccines may also help prevent vaccines from becoming less effective in the face of new variants. As the virus evolves, the portion of it that a vaccine targets may change, reducing the vaccine’s effectiveness. If, on the other hand, two vaccines target distinct components of the virus, the immune system will have several weapons in its arsenal.

 

Thailand’s decision to mix two distinct kinds of vaccine is not only for scientific reasons but also for practical reasons. Mixing doses will provide Thailand with even greater flexibility. As the country currently experiences a supply shortage as a result of a global supply bottleneck, the ability to mix vaccines from several producers may alleviate some of the strain on vaccine supplies. If there is a worldwide scarcity of a specific vaccine, the immunization campaign in Thailand may continue rather than be suspended.

 

The authorized COVID-19 vaccines around the world are all designed to stimulate the immune system, the body’s defense against infection. Hence, the mix-and-match regiment should work according to fundamental vaccine principles. Although there is currently little evidence on whether the degree of protection remains consistent when doses are mixed, data on vaccines has been rapidly accumulating during the pandemic. Therefore, the administration of COVID-19 vaccines may change in the future.

 

nnt.jpg
  • Confused 1
Posted
13 hours ago, smedly said:

They also said it should not be done without extensive clinical trials to ensure it was safe and effective

We are all guinea pigs! The games they play? Why don't they just give everyone 2 AZ vaccines and be done with it. Please don't show everyone how smart you are.

  • Like 1
Posted
5 minutes ago, smedly said:

There is a very simple explanation for this and I 100% agree with your comment  

 

1. Sinsovac has shown to be less effective against delta and over time 3-6 months protectect fades.

 

2. They have already committed to millions of Sinovac but still not enough on its own, also I suspect some fancy fexible accounting going on.

 

3. They do not have enough AZ - not even close 

 

so they are trying to compromise by boosting sinovac with AZ because they have no choice - sinovac on its own is not good enough but they have committed to it.

 

The reality is as everybody knows - they have messed up big time 

 

It also seems that people who have recieved sinovac already will need a do-over with AZ or another vaccine because of the above - so they are basically up the creek without a paddle 

 

 

And they are making everyone with government jobs take these two unproven vaccines.

Posted
10 minutes ago, vandeventer said:

And they are making everyone with government jobs take these two unproven vaccines.

they claim to have tested this combination which I do not believe or at least nothing that can be assessed or reviewed - desperate people do desperate things 

 

Proper studies were carried out in Germany for combination AZ and Pfizer - I do not believe any such in depth study has been carried out in Thailand for AZ and sinovac - they made some claims

  • Like 1
  • Haha 1
Posted
On 7/27/2021 at 5:32 PM, snoop1130 said:

To maximize the usefulness of every tool available for the pandemic response

No I can't it'll be a definite suspension again.

Posted

My understanding is there are studies in progress, possibly close to completion - giving the decision makers enough information that they have decided it prudent to proceed.

 

I note the following chart from an ongoing Thai study into mixing vaccines (Sinovac and AstraZeneca).  The Thai language reference is here:  https://mgronline.com/qol/detail/9640000072391

 

Below is a reduced version of the chart from that article:.

The chart compares:

  •     Sinovac - full (2 jab) vaccination.
  • Sinovac 1 jab + 2nd jab AstraZeneca.
  • AstraZeneca - 2 jabs.
  • Sinovac 2 jabs + 3rd-booster jab AstraZeneca <<<<<< this gives the best of those of the top 4 points in this bullet list (vaccine jabs) compared.
  • Pfizer two jabs - however the Pfizer data is very very limited so it result is most possibly much much higher/better for Pfizer than shown in the plot (ie there probably was not point to show such IMHO).

   

Natural infection (resistance) - ie if I understand this correctly, someone who has caught the virus (4 to 8 weeks after catching the virus) - note the spread is very high - ie varies massively from person to person.

 

So I think this (close to completion (?) study) helps illustrate why AstraZeneca is considered useful as a booster jab to Medical Workers who have had 2 Sinovac (only) jabs. .... I also think this 'ongoing' study is against the delta variant < not sure >

2021-07_thai-study-800w.jpeg.4794aa36f778d6785d992ba06b3d83f0.jpeg

Posted
16 hours ago, Scrotobike said:

I support vaccinations but mixing them without full independently verified trials? Is Thailand the only country doing this or is there a first world country adopting 2 vaccinations - mixed?

 

A cynic may suggest this is to use up the sinovac....

I'm a cynic.

  • Like 1
Posted
18 hours ago, Scrotobike said:

I support vaccinations but mixing them without full independently verified trials? Is Thailand the only country doing this or is there a first world country adopting 2 vaccinations - mixed?

 

A cynic may suggest this is to use up the sinovac....

and i my friend am a cynic  ... in thailand of course             usa mix match inhale snort  anything it takes to get the vaccine and then add more just to be sure ... this is a pandemic   usa is first in cases  https://www.arcgis.com/apps/dashboards/bda7594740fd40299423467b48e9ecf6

i am so ashamed of my gov officials   .. they are the most ignorant self possessed people ..

Posted (edited)
7 hours ago, smedly said:

they claim to have tested this combination which I do not believe or at least nothing that can be assessed or reviewed - desperate people do desperate things 

 

Proper studies were carried out in Germany for combination AZ and Pfizer - I do not believe any such in depth study has been carried out in Thailand for AZ and sinovac - they made some claims

Those tests were carried out, but from what I've read ( a statement by the WHO ) they were NOT and should NOT be in relation to a single shot of each. It was 2 shots AZ followed by 2 shots of Pfizer. I will be mixing and matching. I've already had my first AZ shot. 2nd shot is scheduled for 1 Oct. After 2nd AZ shot I will then get 2 shots of Moderna once it's available. Where I'm living the villagers want nothing to do with Sinovac. They've been refusing Sinovac and demanding AZ.

Edited by TigerandDog
Posted
7 hours ago, TigerandDog said:

Those tests were carried out, but from what I've read ( a statement by the WHO ) they were NOT and should NOT be in relation to a single shot of each. It was 2 shots AZ followed by 2 shots of Pfizer.

incorrect - the tests in Germany were one shot of AZ and one shot of Pfizer 

 

it was a proper published study in Germany unlike Thailand were they just made a claim and supported it with nothing but words

Posted
10 hours ago, smedly said:

incorrect - the tests in Germany were one shot of AZ and one shot of Pfizer 

 

it was a proper published study in Germany unlike Thailand were they just made a claim and supported it with nothing but words

so you're saying the statement made by WHO was wrong, is that correct.

Posted
10 minutes ago, TigerandDog said:

so you're saying the statement made by WHO was wrong, is that correct.

can you not read

Posted
Just now, smedly said:

can you not read

I can read, you say that the report was for single shot mixtures. WHO said that was not the case that it was for 2 shots of each. So answer the question, are you saying WHO was wrong with their statement.

Posted
56 minutes ago, TigerandDog said:

I can read, you say that the report was for single shot mixtures. WHO said that was not the case that it was for 2 shots of each. So answer the question, are you saying WHO was wrong with their statement.

why are you going on about this - why don't you help yourself and look into it - maybe that is beyond your capabilities so I will assist 

 

Mix and match COVID-19 vaccines safe and effective: German study (news-medical.net)

Posted (edited)
7 hours ago, smedly said:

why are you going on about this - why don't you help yourself and look into it - maybe that is beyond your capabilities so I will assist 

 

Mix and match COVID-19 vaccines safe and effective: German study (news-medical.net)

I've read the report, and you've still failed to address my question. WHO stated that this was reported incorrectly, and that the test actually involved 2 shots of each vaccine. So again, answer my question, are you saying that WHO is wrong in their statement.

 

See this statement from WHO reported by Reuters: "GENEVA, July 13 (Reuters) - The World Health Organization's chief scientist has advised individuals against mixing and matching single doses of COVID-19 vaccines from different manufacturers." 

 

So who are you going to believe, a German report from June, OR a more recent report from 13 July by WHO. Yes there are tests STILL underway with regards to mix & match single doses of different vaccines, BUT NO definitive results yet.

Edited by TigerandDog
Posted
1 hour ago, TigerandDog said:

I've read the report, and you've still failed to address my question. WHO stated that this was reported incorrectly, and that the test actually involved 2 shots of each vaccine. So again, answer my question, are you saying that WHO is wrong in their statement.

 

See this statement from WHO reported by Reuters: "GENEVA, July 13 (Reuters) - The World Health Organization's chief scientist has advised individuals against mixing and matching single doses of COVID-19 vaccines from different manufacturers." 

 

So who are you going to believe, a German report from June, OR a more recent report from 13 July by WHO. Yes there are tests STILL underway with regards to mix & match single doses of different vaccines, BUT NO definitive results yet.

bye bye - ignored

Posted
22 hours ago, TigerandDog said:

so you're saying the statement made by WHO was wrong, is that correct.

Their statement actually said it should be studied more which is what other countries have done.

Posted
4 hours ago, hioctane said:

Their statement actually said it should be studied more which is what other countries have done.

that was a different statement. The one I'm referring to was saying the German report on the success of mixing single doses of AZ and Pfizer was incorrectly reported. The tests that the German report was referring to were actually for 2 doses of AZ then 2 doses of Pfizer. They also clarified in that report that testing was still ongoing in relation to mixing single doses of AZ & Pfizer. In fact WHO came out in a press release on 13 July ( one month after the German report and their subsequent statement saying that German report was incorrect ) and stated that single dose mixing and matching of different vaccines was not recommended until further testing had been completed.

Posted

It's "my personal choice" not to mix vaccines, and I pity the moron (we all know who) that tells me "I don't have a choice". If it's "your personal choice" to mix vaccines I wish you good luck, wealth and happiness...

Posted
8 hours ago, TigerandDog said:

that was a different statement. The one I'm referring to was saying the German report on the success of mixing single doses of AZ and Pfizer was incorrectly reported. The tests that the German report was referring to were actually for 2 doses of AZ then 2 doses of Pfizer. They also clarified in that report that testing was still ongoing in relation to mixing single doses of AZ & Pfizer. In fact WHO came out in a press release on 13 July ( one month after the German report and their subsequent statement saying that German report was incorrect ) and stated that single dose mixing and matching of different vaccines was not recommended until further testing had been completed.

I don't understand this at all  -  I think maybe you have misunderstood what you have read?

 

Firstly there are only two German studies that I can find that trial mixing doses of the Astra Zeneca (ChAdOx1) adenovirus vaccine and the Pfizer (BNT162b2) mRNA vaccine.

 

Both are published as preprint papers on the medrxiv server, and both clearly report in their methods section that they study the results of a single dose of each vaccine,  and not two doses of each.  I give you the links and actual extracts of the papers detailing their dosing methods below at the end of the post.

 

There is no way any WHO statement can override or correct the dosing methods stated in print by the actual researchers in their papers, so this seems a very unlikely statement for them to make.  

 

Moreover I can find no trace of any WHO statement which actually does this with reference to doses.   The one you link to on July 13th [https://www.reuters.com/business/healthcare-pharmaceuticals/who-warns-against-mixing-matching-covid-vaccines-2021-07-12/] does not mention doses at all.  While they certainly recommend against mixing vaccines, they do not discount this altogether.

 

It says private individuals should not decide whether to mix vaccines, but state or public health agencies should make this decision. The actual Reuters article you link to specifically quotes the WHO saying:

 

"The WHO's Strategic Advisory Group of Experts on vaccines said in June the Pfizer Inc (PFE.N) vaccine could be used as a second dose after an initial dose of AstraZeneca (AZN.L), if the latter is not available."

 

I may have not been able to find the WHO statement you mention with dosing information-if so I apologise and would appreciate a link or quote.

 

***********

The German papers describing single dosing with each vaccine:

 1https://www.medrxiv.org/content/10.1101/2021.06.01.21258172v1.full-text

Humoral and cellular immune response against SARS-CoV-2 variants following heterologous and homologous ChAdOx1 nCoV-19/BNT162b2 vaccination Barros-Martins, J et al (2021) " Vaccinees who received one dose of ChAd were, according to the current vaccination strategy in Germany, offered to choose between ChAd and BNT vaccines for a second dose. "

2. https://www.medrxiv.org/content/10.1101/2021.05.19.21257334v2.full.pdf+html

Safety, reactogenicity, and immunogenicity of homologous and heterologous prime-boost immunisation with ChAdOx1-nCoV19 and BNT162b2: a prospective cohort study Hillus D, et al (2021) "Study participants either received two doses of BNT three weeks apart or an initial dose of ChAdOx followed by a heterologous boost with BNT 10-12 weeks later, in accordance with the recommendations of the German standing committee on vaccination (STIKO)."

 

  • Like 2
Posted (edited)

There is also a Spanish study and a UK study that examined a single dose of AZ followed by a single dose of Pfizer (and visa versa).

Edited by oldcpu
Posted
On 7/27/2021 at 8:10 PM, Scrotobike said:

I support vaccinations but mixing them without full independently verified trials? Is Thailand the only country doing this or is there a first world country adopting 2 vaccinations - mixed?

 

A cynic may suggest this is to use up the sinovac....

It’s not difficult to understand 

 

You make the most of what you have. Right now they have Sinovac and AZ and the best way of vaccinating as many people as possible is to mix the doses. 
 

They can’t magic up other brand of vaccines, this is what they have to work with 

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.



×
×
  • Create New...