Vaccination Decisions in Philippines. Mix or Match?

[Pelagic]

In most developing countries, vaccine availability is dependent on the largesse of those countries who have an overstock and need to gift as foreign aid, before the vaccine expires .

That is the case in the Philippines where last minute availability, leads to crisis management.
Often there is no guarantee of a 2nd dose of same product.

I got my first dose of Astrozenica yesterday in Subic Freeport. Last minute, but very well organized via an online application and apointment .
It was also free!

Only about 600 Vacinnes available and no idea of when more will be here.

My Decision quandary is that i ordered COVOVAX privately thru the Subic Chamber of Commerce, for Zaida and I.

Now paid for and due early July.

IS IT SAFE TO USE COVOVAX AS A 2ND DOSE AFTER ASTROZENICA ??

FYI, I have also signed up via RED CROSS to buy one donate one of MODERNA at a hefty price

This is also now due late July.

I plan on donating whatever we dont use ....so 2nd Option...

IS IT SAFER TO USE MODERNA AS A 2ND DOSE AFTER ASTROZENICA ??

If anyone has some up to date studies on this MIX OR MATCH question, I would apprecate the link
Thanks !

[Marathon1150]

I'm not an expert but this article published about 2 weeks ago in Nature (highly reputable science journal published in the UK) has some comments re mix and match of vaccines:

https://www.nature.com/articles/d41586-021-01359-3

Here is a cut and paste of the 1st two paragraphs from the article (but do read the entire thing - it includes views from a variety of virologists and epidemiologists):

++++++++++++++++++++++++++
Vaccinating people with both the Oxford–AstraZeneca and Pfizer–BioNTech COVID-19 vaccines produces a potent immune response against the virus SARS-CoV-2, researchers conducting a study in Spain have found.

Preliminary results from the trial of more than 600 people — announced in an online presentation on 18 May — are the first to show the benefits of combining different coronavirus vaccines. A UK trial of a similar strategy reported1 safety data last week, and is expected to deliver further findings on immune responses soon.
++++++++++++++++++++++++

Note that this article is a report on a study based on a presentation of the results. This means that the work has probably not yet been published in a peer reviewed journal (that can take months or longer).

Also, the sample size (600) is relatively small given the number of people who are being vaccinated so I would consider the results as indicative rather than definitive. It is likely that more data and publications will be forthcoming for a variety of reasons.

I also note that Covovax, is a version of the Novovax vaccine being produced under license by the Serum Institute of India. It is a "protein" vaccine as opposed to Astrazeneca which uses a modified cold virus as a carrier of a portion of the Covid-19 virus. Moderna and Pfizer-BIONtech are mRNA vaccines - a very new kind of vaccine technology that uses mRNA to instruct the recipients cells to make a piece of C-19 virus spike protein.

The Nature article goes on to say:

+++++++++++++++++++++
That is what researchers hoped for and expected from mixing different vaccines, a strategy known as a heterologous prime and boost, which has been deployed for vaccines against other diseases, such as Ebola. “These responses look promising and show the potential of heterologous prime–boost regimens,” says Dan Barouch, director of the Center for Virology and Vaccine Research at Beth Israel Deaconess Medical Center in Boston, Massachusetts.
+++++++++++++++++++++

I'm not a virologist so I would not extrapolate beyond the initial indications that mixing Astrazeneca and Pfizer-Biontech seems to work quite well. If time permits, you might want to wait a bit longer before making a final decision. More data is going to reveal which mix and match produces the best results.

[sailorboy1]

Man, asking a boating forum a medical question

I certainly wouldn't take doses of different vaccines not tested for. I probably is ok, but .......

[JPA Cate]

@Pelagic:

There is a doctor on CF. His screen name is <bensolomon>, and he has been generous with sharing information. Perhaps a PM to him with a link to this thread might earn you an answer to your interesting question.

Ann

[LittleWing77]

Moderna and Pfizer are the same type of vaccine, Pelagic (mRNA) - just different manufacurers.

If you're wanting the comfort of staying with the same type of vaccination, go with the Moderna (despite the hefty price). Also I believe the most efficacious space between doses is 12-16 weeks (more than 21 days, as was originally recommended) - so you have some time.

That said, data is beginning to accumulate that mixing might be okay, and as suggested by Marathon in Post #2 above, wait and watch for updated info on mixing, which is being aggregated as we speak.

Good luck!
LittleWing77

[GordMay]

Canada to recommend mixing and matching AstraZeneca, Pfizer and Moderna COVID-19 vaccines
NACI guidance based on early research from U.K., Spain that shows mixing shots is safe and effective
➥ https://www.cbc.ca/news/health/canad...naci-1.6048152

Mixing COVID-19 vaccine doses leads to more reactions, study finds, which may be 'first sign of success'
➥ https://www.cbc.ca/news/health/vacci...oses-1.6023830

Spanish study finds AstraZeneca vaccine followed by Pfizer dose is safe and effective
➥ https://www.reuters.com/business/hea...fe-2021-05-18/

[valhalla360]

Two main reasons mix and match aren't being recommended:
- It hasn't been studied for effectiveness. There is no reason to expect it to be harmful nor that it won't be highly effective. In theory, if you pick two different types, it should be more effective as it triggers different parts of the immune system....they just haven't proven it.
- The manufacturers don't want to lose a guaranteed return customer.

[GordMay]

Originally Posted by valhalla360

Two main reasons mix and match aren't being recommended:
- It hasn't been studied for effectiveness. There is no reason to expect it to be harmful nor that it won't be highly effective. In theory, if you pick two different types, it should be more effective as it triggers different parts of the immune system....they just haven't proven it.
- The manufacturers don't want to lose a guaranteed return customer.

As I previously reported [post #6], it has been studied, with favourable [safe & effective] results.
Although, perhaps not definitive, these early studies tend to confirm the theory that hat such mix-and-match COVID-19 vaccination regimens will trigger stronger, more robust immune responses, than will two doses of a single vaccine, while simplifying immunization efforts for countries facing fluctuating supplies of the various vaccines.

The findings of a U.K. study [‘Com-COV’] were published as correspondence, not as a full study, in The Lancet, and came from the Oxford Vaccine Group's Com-Cov vaccine trial, which is studying the use of different combinations of approved COVID-19 vaccines for first and second doses.

“Heterologous prime-boost COVID-19 vaccination: initial reactogenicity data”
➥ https://www.thelancet.com/journals/l...115-6/fulltext
➥ https://www.thelancet.com/action/sho...2821%2901115-6

A Spanish study [‘Combivacs’] on mixing COVID-19 vaccines has found that giving a dose of Pfizer's (PFE.N) drug to people who already received a first shot of AstraZeneca (AZN.L) vaccine is highly safe and effective, preliminary results showed.
➥ https://www.isciii.es/Noticias/Notic...CombivacS.aspx

[valhalla360]

Originally Posted by GordMay

As I previously reported [post #6], it has been studied, with favourable [safe & effective] results.
Although, perhaps not definitive, these early studies tend to confirm the theory that hat such mix-and-match COVID-19 vaccination regimens will trigger stronger, more robust immune responses, than will two doses of a single vaccine, while simplifying immunization efforts for countries facing fluctuating supplies of the various vaccines.

The findings of a U.K. study [‘Com-COV’] were published as correspondence, not as a full study, in The Lancet, and came from the Oxford Vaccine Group's Com-Cov vaccine trial, which is studying the use of different combinations of approved COVID-19 vaccines for first and second doses.

“Heterologous prime-boost COVID-19 vaccination: initial reactogenicity data”
➥ https://www.thelancet.com/journals/l...115-6/fulltext
➥ https://www.thelancet.com/action/sho...2821%2901115-6

A Spanish study [‘Combivacs’] on mixing COVID-19 vaccines has found that giving a dose of Pfizer's (PFE.N) drug to people who already received a first shot of AstraZeneca (AZN.L) vaccine is highly safe and effective, preliminary results showed.
➥ https://www.isciii.es/Noticias/Notic...CombivacS.aspx

Ok, detailed, double blind, long term, etc., etc., etc., studies haven't been completed.

[GordMay]

Originally Posted by valhalla360

Ok, detailed, double blind, long term, etc., etc., etc., studies haven't been completed.

Indeed.
Com-COV2 Protocol [UK/Oxford Study]
A single-blind, randomised, phase II UK multi-centre study to determine reactogenicity and immunogenicity of heterologous prime/boost COVID-19 vaccine schedules – Stage 2
V2.123-Apr-2021 ➥ https://comcovstudy.org.uk/files/com...r-2021cleanpdf
V6.0 19-May-2021 ➥ https://comcovstudy.org.uk/files/com...19-may-2021pdf

[Pelagic]

Originally Posted by LittleWing77

Moderna and Pfizer are the same type of vaccine, Pelagic (mRNA) - just different manufacurers.

If you're wanting the comfort of staying with the same type of vaccination, go with the Moderna (despite the hefty price). Also I believe the most efficacious space between doses is 12-16 weeks (more than 21 days, as was originally recommended) - so you have some time.

That said, data is beginning to accumulate that mixing might be okay, and as suggested by Marathon in Post #2 above, wait and watch for updated info on mixing, which is being aggregated as we speak.

Good luck!
LittleWing77 [emoji3]

Thank you little wing, I was not aware that they had increased the wait time between doses.

To clarify, I may not get a chance at a 2nd dose of Astrazenica and atthe moment COVOVAX seems to be the most likely, and Moderna is not confirmed .

So the question brcomes more...
.....is it better to get that 2nd shot in the arm, rather than wait for a match?

[GordMay]

Originally Posted by Pelagic

Thank you little wing, I was not aware that they had increased the wait time between doses.
To clarify, I may not get a chance at a 2nd dose of Astrazenica and atthe moment COVOVAX seems to be the most likely, and Moderna is not confirmed
So the question brcomes more...
.....is it better to get that 2nd shot in the arm, rather than wait for a match?

“Extended dose intervals for COVID-19 vaccines to optimize early vaccine rollout and population protection in Canada in the context of limited vaccine supply” ~ National Advisory Committee on Immunization (NACI): Statements and publications

As a general vaccination principle, interruption of a vaccine series resulting in an extended interval between doses does not require restarting the vaccine series, regardless of the interval between doses [33]. Principles of vaccinology support at least a three-week interval between doses in a multi-dose primary series to avoid immune interference in the primary response to the vaccine [34]. Furthermore, a longer interval between the priming and boosting doses allows maturation of the memory B cells, resulting in a higher and more durable response [34].

Data from the AstraZeneca COVID-19 vaccine clinical trial showed maximum efficacy when the interval was extended to ≥12 weeks, with efficacy at <6 weeks between doses of 55.1% (95% CI: 33.0 to 69.9%) and efficacy at ≥12 weeks of 81.3% (60.3 to 91.2%) [5].

NACI Guidance ➥ https://www.canada.ca/en/public-heal...tion.html#a4.3

[joelhemington]

Originally Posted by GordMay

As I previously reported [post #6], it has been studied, with favourable [safe & effective] results.
Although, perhaps not definitive, these early studies tend to confirm the theory that hat such mix-and-match COVID-19 vaccination regimens will trigger stronger, more robust immune responses, than will two doses of a single vaccine, while simplifying immunization efforts for countries facing fluctuating supplies of the various vaccines.

The findings of a U.K. study [‘Com-COV’] were published as correspondence, not as a full study, in The Lancet, and came from the Oxford Vaccine Group's Com-Cov vaccine trial, which is studying the use of different combinations of approved COVID-19 vaccines for first and second doses.

“Heterologous prime-boost COVID-19 vaccination: initial reactogenicity data”
➥ https://www.thelancet.com/journals/l...115-6/fulltext
➥ https://www.thelancet.com/action/sho...2821%2901115-6

A Spanish study [‘Combivacs’] on mixing COVID-19 vaccines has found that giving a dose of Pfizer's (PFE.N) drug to people who already received a first shot of AstraZeneca (AZN.L) vaccine is highly safe and effective, preliminary results showed.
➥ https://www.isciii.es/Noticias/Notic...CombivacS.aspx

While it seems that mixing the vaccines is the way to go. I get the sneaky feeling that they're not really sure. I think I'm going to let the practice of medicine practice on somebody else for awhile.

[S/V Illusion]

Originally Posted by sailorboy1

Man, asking a boating forum a medical question

I certainly wouldn't take doses of different vaccines not tested for. I probably is ok, but .......

I thought asking for financial advice here was silly but asking for medical advice here wins the prize. Dueling internet links doesn’t make a sound basis for any judgment.

[Pelagic]

Originally Posted by S/V Illusion

I thought asking for financial advice here was silly but asking for medical advice here wins the prize. Dueling internet links doesn’t make a sound basis for any judgment.

You and sailorboy are under the illusion that I would make that decision based on opinions.

I asked for links to studies on the subject and I have done the same elsewhere.

The reason I include CF is that this may be helpful to other sailors in 3rd world locations, facing a similar decision .

The bottom line, we study and try to make an informed decision