Covid-19 vaccines and vaccinations

Abstract
Beyond their substantial protection of individual vaccinees, coronavirus disease 2019 (COVID-19) vaccines might reduce viral load in breakthrough infection and thereby further suppress onward transmission. In this analysis of a real-world dataset of positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test results after inoculation with the BNT162b2 messenger RNA vaccine, we found that the viral load was substantially reduced for infections occurring 12–37 d after the first dose of vaccine. These reduced viral loads hint at a potentially lower infectiousness, further contributing to vaccine effect on virus spread.
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https://www.nature.com/articles/s41591-021-01316-7
 
MeSci said:
I can't view it for free.
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Should I paste the item? Don't recall the rules. I subscribe, so I guess that is why I received it; but I understood there were a certain number of times folks could open up the pages without a subscription.
 
Sasha said:
Thanks - but I'm specifically interested on whether the vaccine is preventing cases of Long Covid from developing in the first place, as opposed to affecting existing cases.
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Check this preprint out. These results suggest preventing asymptomatic infection.

https://www.authorea.com/users/3327...cts-against-asymptomatic-sars-cov-2-infection

We therefore provide real-world evidence for a high level of protection against asymptomatic SARS-CoV-2 infection after a single dose of BNT162b2 vaccine, at a time of predominant transmission of the UK COVID-19 variant of concern 202012/01 (lineage B.1.1.7), and amongst a population with a relatively low frequency of prior infection (7.2% antibody positive).5
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For what it's worth, the Public Health Agency of Sweden has for the first time published some data on covid-19 infections among the vaccinated population:
In total, more than one million people in Sweden have been vaccinated with one dose and about 430,000 people with two doses. About 6,000 people have so far been found to have covid-19 after their first vaccine dose. Almost 4,000 of them tested positive within the first two weeks after the first dose, ie before the body had time to build up a protection. Only about 200 people were found to have been infected with covid-19 more than two weeks after the second dose. This corresponds to 0.07 percent of the total number of covid-19 cases since the turn of the year, and 0.06 percent of all those vaccinated with two doses. [...]

It is not known how many of those who were vaccinated and then tested positive for covid-19, had symptoms or needed medical attention. The data collected also do not state why these individuals were sampled for covid-19. It may have occurred either due to symptoms, or in connection with screening and infection tracing around confirmed cases.
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Få fall av covid-19 bland vaccinerade personer
https://www.folkhalsomyndigheten.se...-fall-av-covid-19-bland-vaccinerade-personer/

Google Translate, English
 
Is it true that the Astra Zeneca vaccine will be more effective if the 2nd dose is delayed until 90 days? Or is it more effective if given around the 28 day mark or as soon as possible after that?
 
I watched this interview on CNN last night about a women who says she recovered from LC from the Pfizer vaccine. A doctor (Dr. William Li) is very interested in this, and Chris Como mentioned that he was being 'treated' with supplements for lingering symptoms of LC that this doctor recommends.

 
lunarainbows said:
Is it true that the Astra Zeneca vaccine will be more effective if the 2nd dose is delayed until 90 days? Or is it more effective if given around the 28 day mark or as soon as possible after that?
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Long term, I suspect the efficacy of the second dose at both intervals is probably the same. In the short term (3 months after the second dose), there is suggestive evidence that the 12 week interval could lead to higher effiacy.

The second dose of the AZ vaccine doesn't have the same function or effect as the second dose of the mRNA vaccines. The second dose of the mRNA vaccines at ~3 weeks lead to further germinal centre activity and lead to increased quality of neutralising antibodies, but does not lead to a significant increase in antibody titre.

A second AZ dose at this 3 week interval doesn't seem to provide that benefit, likely due to strong anti-vector immune responses. At ~12 weeks, the second dose functions as a booster, leading to clonal expansion of the existing B-cells that are sensitive to the spike protein, leading to a temporary boost in antibody titre. But efficacy (particularly long-term) is not merely a function of antibody titre, it depends on quality as well as quantity...
 
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Wonko said:
So...AZ produces more, but not a broad a spectrum, and therefore lower 'quality' when met with a real world varied cohort of covid-19 viruses?
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Given that the spike protein itself is almost identical between the mRNA and Adenovirus vectored vaccines, the main differences are the anti-vector immune responses.

This is an 'in mice' study, but testing the whole LD/SD thing, an initial lower dose lead to greater germinal centre activity two weeks after the second dose (4 weeks apart). https://www.biorxiv.org/content/10.1101/2021.03.31.437931v1

I hypothesise based on this evidence that long term, LD/SD/4 weeks would lead to better efficacy than SD/SD/12 weeks for the adenovirus vectored vaccines. Also, this may be why combinations like the 'Sputnik' vaccines provide better efficacy than single adenovirus vectored vaccines.

I'd also like to point out that most other viral-vector vaccine candidates (based on other viruses have ceased development, due to poor efficacy. The adenovirus based vectors may be close to the best we can achieve with viral vectors.
 
From: Dr. Marc-Alexander Fluks


Source: UK House of Commons
Date: April 1, 2021
URL:
https://questions-statements.parliament.uk/written-questions/detail/2021-03-19/172025
Ref: http://www.me-net.combidom.com/meweb/web1.4.htm#westminster


[Written Answers]

Coronavirus: Vaccination
------------------------

Andrew Gwynne

To ask the Secretary of State for Health and Social Care, for what reason people with chronic fatigue syndrome (CFS/ME) are being offered the covid-19 vaccine in some areas of the country and not in others.


This answer is the replacement for a previous holding answer.


Nadhim Zahawi

To date, chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) has not been identified as a condition that makes an individual clinically extremely vulnerable to COVID-19 or would place an individual at increased clinical risk. It is likely that some people with CFS/ME are being offered vaccines because they are eligible through other means such as their age or they have other underlying health issues that would it put them at increased clinical risk.
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