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Tue Apr 20, 2021, 02:48 AM

Substantial Differences in SARS-CoV-2 Ab Responses Elicited by Natural Infection and mRNA Vaccine

Last edited Tue Apr 20, 2021, 12:47 PM - Edit history (1)

This is really, really good news. It was difficult choosing only a few paragraphs to quote, so I encourage you to follow the link to read more, if only the "Discussion" section.

What it says, though, is that mRNA vaccine immunity appears to be superior to natural immunity--for various reasons they describe (some included below).

https://www.biorxiv.org/content/10.1101/2021.04.15.440089v1.full.pdf+html

In this study, we compared antibody responses induced by SARS-CoV-2 natural exposure with the responses induced by the mRNA vaccines.

(snip)

mRNA vaccines induce higher Ab levels and greater Ab breadth than natural exposure to infection and differences were particularly notable against the RBD domain. ... (snip) ...The virus uses the spike RBD domain that binds to the ACE2 receptor on respiratory cells to enter and infect them. Vaccinated individuals had significantly elevated Ab levels against RBD domain segments, supporting the protective immunity induced by this vaccine as previously published. To account for this difference between natural exposure and the vaccine, the virus may have evolved to conceal the RBD epitope to evade immune recognition. The mRNA vaccine produces a protein conformation that better exposes the RBD epitope to the immune system.

In addition to inducing increased Ab levels again SARS-CoV-2 RBD, the mRNA vaccine induced cross-reactive responses against SARS spike and SARS RBD. Conversely, natural exposure did not induce a cross-reactive response against the SARS spike and SARS RBD. The weak anti-RBD response induced by natural exposure may provide a mechanism for new variants to enter the population. This result can be interpreted based on immune selection pressure. Importantly, the mRNA vaccine induces a marked cross-reactive response against SARS spike, indicating that the mRNA vaccine adopts a conformation that presents cross-reactive epitopes to the immune system. This effect of the mRNA vaccine to induce cross-reactivity against diverse CoV strains is encouraging, providing further evidence that it may be effective against emerging virus variants.

(snip)

These results may also have relevance for both the dose response hypothesis and with regard to herd immunity. Several authors have suggested that disease outcomes may be related to the dose inoculum, with individuals being exposed to inocula with higher virus loads potentially having more severe disease outcomes. [9] While the currently used vaccines in this setting do not rely on viral materials, they do offer a glimpse into controlled high level exposure to proteins that are specific to SARS-CoV-2. Our results show that individuals who have been vaccinated mount higher across-the-board antibody responses than those who have been exposed to variable viral inocula (i.e. through natural exposure). Second, the variable antibody responses among the pre-vaccine population may also indicate that immune responses to natural infections are not as strong as those among individuals who have been vaccinated. This could also indicate that immunity from naturally acquired infections is not as strong as that acquired from vaccination, with potential relevance for reaching and maintaining herd immunity. We should not assume that previously infected individuals are immune or that they cannot transmit the virus.


ETA: adding the standard disclaimer for all pre-print articles posted on bioRxiv
bioRxiv is receiving many new papers on coronavirus SARS-CoV-2. A reminder: these are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information.

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Reply Substantial Differences in SARS-CoV-2 Ab Responses Elicited by Natural Infection and mRNA Vaccine (Original post)
intrepidity Apr 2021 OP
stopdiggin Apr 2021 #1
berni_mccoy Apr 2021 #2
intrepidity Apr 2021 #6
burrowowl Apr 2021 #3
jaxexpat Apr 2021 #4
Native Apr 2021 #5

Response to intrepidity (Original post)

Tue Apr 20, 2021, 05:06 AM

1. fantastic news! thanks for the link (and short synopsis).

I'm not sure this is as counter-intuitive as I first thought -- but it certainly is completely new!

Keep getting the shots, good people! (and, IMO anyway, let's ditch the idea of the 'deferred second shot' completely. the higher levels of immunity are worth fighting for!)

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Response to intrepidity (Original post)

Tue Apr 20, 2021, 05:23 AM

2. It showed immune response to SARS and MERS as well

 

In people given the vaccine. That is really good news for protecting against variants!

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Response to berni_mccoy (Reply #2)

Tue Apr 20, 2021, 12:44 PM

6. Yes, thanks for pointing that out

We tend to think of "variants" as future/emerging, but that also includes known versions such as SARS-1 and MERS.

In addition to inducing increased Ab levels again SARS-CoV-2 RBD, the mRNA vaccine induced cross-reactive responses against SARS spike and SARS RBD. Conversely, natural exposure did not induce a cross-reactive response against the SARS spike and SARS RBD. The weak anti-RBD response induced by natural exposure may provide a mechanism for new variants to enter the population. This result can be interpreted based on immune selection pressure. Importantly, the mRNA vaccine induces a marked cross-reactive response against SARS spike, indicating that the mRNA vaccine adopts a conformation that presents cross-reactive epitopes to the immune system. This effect of the mRNA vaccine to induce cross-reactivity against diverse CoV strains is encouraging, providing further evidence that it may be effective against emerging virus variants.

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Response to intrepidity (Original post)

Tue Apr 20, 2021, 05:41 AM

3. Great news!

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Response to intrepidity (Original post)

Tue Apr 20, 2021, 06:15 AM

4. Protection against variants and potential variants is pretty much perfect.

If only there were a vaccine against intentional ignorance. The antidote for which is, IMHO, waving life's traffic in the direction it's going.

Simply allow the path to choose your walk. In time the current will always flow, its direction a mystery yet unerringly true. It is for the individual to accept living without the burden of fear. If it sounds simple, well it is, except for the distractions, the entertainments great and small, and ego dramas in this world of molecules, our temporary material domain. So, in a realm where our worst enemies are imaginary things, it is logical and unavoidable that those drowning in their struggles against the flow will choose the wrong response to the current, or any, emergency.

This has been my temporary moment of Zen which I've shared with you because I can.

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Response to intrepidity (Original post)

Tue Apr 20, 2021, 06:21 AM

5. Wow, great stuff. Forwarding this to all those in my life who need convincing.

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