Introduction, the primary cause of spread???

According to the CDC, unvaccinated are the primary or in other words MAJOR cause of the continuation of the spread. In this article they say this and then link you to the last part of the page

SARS-CoV-2 transmission between unvaccinated persons is the primary cause of continued spread.

Something can only be the major/primary cause if it forms a clear causal relationship and the strongest one at that. Usually that means that it's impact is always noticed even barring other lesser influences, especially the more data points you have. Thus this paper¹ alone, already disproofs said claim by the CDC. Even a causal clear relationship can't even be found between 2947 counties, then there is not a strong causal relationship, in this case thus not one that was significant. Let's also make it clear that spread is indicated by infections/cases, not EVER by hospitalizations nor deaths.

According to what Biden said² on national TV, he clearly lied, because he made a claim he knew he couldn't be sure about and now it has been proven with the above paper.

Places with high vaccination rates will also see fewer cases of COVID moving forward. Places with lower vaccination rates are going to see more.

The arguments the CDC provides and their discussion

First paragraph

Nonetheless let's focus on the evidence/arguments the CDC provides for their claim in the subsection "Infections in fully vaccinated persons: clinical implications and transmission". In the whole first paragraph they don't address transmission and don't provide really any arguments for the claim the unvaccinated are the PRIMARY reason (they are not claiming they play a part or contribute a bit no their claim is much stronger).

Second paragraph

In the second paragrahp they say something towards this:

However, a study from Houston, Texas observed that Delta caused a significantly higher rate of infections in fully vaccinated people compared with infections from other variants, but noted that only 6.5% of all COVID-19 cases occurred in fully vaccinated individuals(163);

Basically they are trying to imply that the amount of infected people who were vaccinated was low. Well let's first look at what the paper says currently:

we sequenced the genomes of 4,920 SARS-CoV-2 from patient samples acquired March 15, 2021 through July 24, 2021 in the Houston Methodist hospital system and studied vaccine breakthrough cases.

Importantly, only 8.4% of all COVID-19 cases occurred in fully vaccinated individuals, and relatively few of these patients required hospitalization. Individuals with vaccine breakthrough cases caused by Delta variants (n = 194) had a low median PCR cycle threshold (Ct) value (a proxy for high virus load), and this value was not significantly different than the median Ct value observed in unvaccinated patients with COVID-19 caused by Delta variants. These data are consistent with the potential ability of fully vaccinated individuals to transmit SARS-CoV-2 to others.

(bold annotation mine)

we sequenced the genomes of 4,920 SARS-CoV-2 from patient samples acquired March 15, 2021 through July 24, 2021 using an Illumina NovaSeq 6000 instrument5. This period encompasses the time from initial identification of a Delta-related variant in our large Houston Methodist healthcare system until Delta variants became the supermajority (93.7%) of all new cases.

In the aggregate, our data add critical new information to the finding that these three vaccines are highly efficacious in decreasing severe COVID-19 disease, hospitalizations, and deaths.

(bold annotation mine)

Long story short this publication in no proper way addresses a reduction in transmission or infection. It reaffirms the reduction in severity, hospitalizations, and death. However those don't matter for the spread/transmission. Thus the second paragraph and this paper do NOT show that the unvaccinated are the PRIMARY/MAJOR reason/cause. They also did not test randomly selected individuals for covid testing, meaning it was biased result based on severity, which is specifically reduced by the vaccines (Patient samples).

Third paragraph, part I

Let's look at their 3rd paragraph now where they actually try to provide some proper arguments,

In studies conducted before the emergence of the Delta variant, data from multiple studies in different countries suggested that people vaccinated with mRNA COVID-19 vaccines who develop COVID-19 generally have a lower viral load than unvaccinated people.(157, 165-169) This observation may indicate reduced transmissibility, as viral load has been identified as a key driver of transmission.

Yeah well this not only doesn't matter, more specifically this revolved around the very early days with usually people being vaccinated less than 3 months, definitely on average, while waning protection against INFECTION starts waning after that, usually reaching around 20% or lower after 6 months against Delta ³,⁴(we can't say what it does for other variants as they have been out-competed by Delta)

Now as regards to lower viral load which they claim, let's look at some other very clear real life data that does involve Delta. Most sources that I have found expect vaccinated people to be about as infectious as unvaccinated, these being government sources and scientific papers. Keep in mind the lower the Ct (cycle treshold) values the higher the viral load and the more infectionious a person is expected to be.

In the technical briefing number 20 from the UK the following is writing⁵:

In the NHS Test and Trace (NHSTT) case data, the mean and median lowest Ct values for all cases with Delta, where Ct data are available, since the 14 June 2021 are similar, with a median of 17.8 for unvaccinated and 18.0 for those with 2 vaccine doses (Figure 12). This means that whilst vaccination may reduce an individual’s overall risk of becoming infected, once they are infected there is limited difference in viral load (and Ct values) between those who are vaccinated and unvaccinated. Given they have similar Ct values, this suggests limited difference in infectiousness.

Furthermore this scientific publication indicates and mentions similar results followed by an image showing how similar (median) Ct values are ⁶.

Testing a subset of low-Ct samples revealed infectious SARS-CoV-2 in 15 of 17 specimens (88%) from unvaccinated individuals and 37 of 39 (95%) from vaccinated people (Figure 1B).

Even the CDC found similar results, which can be read about in this news article https://www.pbs.org/newshour/health/study-vaccinated-people-who-got-breakthrough-infections-can-carry-as-much-virus-as-others, or in their own rapport ⁷.

Real-time reverse transcription–polymerase chain reaction (RT-PCR) cycle threshold (Ct) values in specimens from 127 vaccinated persons with breakthrough cases were similar to those from 84 persons who were unvaccinated, not fully vaccinated, or whose vaccination status was unknown (median = 22.77 and 21.54, respectively).

Now lastly we'll look at an paper that shows the development of Ct values over time⁸.

The initial median initial Ct value did not differ between unvaccinated and fully vaccinated patients (unvaccinated median Ct 18.8 (14.9-22.7), vaccinated 19.2 (15.2-22.2), p=0.929). However, fully vaccinated patients had a faster rate of increase in Ct value over time compared with unvaccinated individuals, suggesting faster viral load decline ...

Now people will be quick to point out or wonder but if the decline in viral load is significantly quicker then how can you say that they are similarly infectious? Well this is because of how Covid-19 is mostly spread and when. Most of it is spread during peak infectionious which is only around 2-4 days in the beginning of the illness (around incubation).

Now there are two news articles that explain why a minority of people spreads the disease ⁹ First news article

The Fred Hutchinson Cancer Research Center study, which is a preprint study and therefore has not been peer-reviewed, found that COVID-19 is typically passed through “super-spreader events” — and only 20% of those who test positive will transmit it to others.

Super-Spreaders Happen When Someone Is at Their ‘Peak Contagious Point’

and the second news article

“What I mean by that is that there are a relatively small, but really important proportion of spreading events where one person infects 10 people, or sometimes 50 people, or sometimes 100 people,” explained Dr. Schiffer. “Yet 80% of people with this virus don't infect anybody.”

Lastly ¹⁰

Just 2% of SARS-CoV-2−positive individuals carry 90% of the virus circulating in communities

All in all it should look clear why vaccinated people are estimated to be similarly infectious. If it's still not clear we can convert CT values to viral load (virions/ml) and plot it on a log y-axis and on a linear scale. The linear scale will immediately show why this is the case and will be on the right-hand side of the next image (the viral loads were calculated based on the CT values from source/footnote 8).

Third paragraph, part II

Now back to the CDC and what they are saying.

This observation may indicate reduced transmissibility, as viral load has been identified as a key driver of transmission.

So according to the CDC viral load is a key driver of transmission, then according to what I have just shown it should be obvious that unvaccinated aren't significantly more infectious.

Studies from multiple countries found significantly reduced likelihood of transmission to household contacts from people infected with SARS-CoV-2 who were previously vaccinated for COVID-19.(171-176)

Maybe take a look again at the image from the Qatar study that clearly shows the waning of effectivity starts truly dropping after 3 months, not before. When I say 3 months or less, I'm talking about the overwhelming majority of participants being vaccinated 3 months or less, there might be a few that are 3.5 months or so.

• 171 too early, 3 months or less, February to May 2021
• 172 too early, 3 months or less, Between January 4 and February 28, 2021
• 173 too early, 3 months or less, From December 2020 to April 2021
• 174 too early, 3 months or less, The full dataset, covering the period from June 15, 2020 to March 24, 2021
• 175 too early, 3 months or less, (December 27, 2020) and March 24, 2021 in Finland
• 176 too early, 3 months or less, 8th December 2020 to 3rd March 2021

Third paragraph, part III

Great let's look at the next part,

For the Delta variant, early data indicate vaccinated and unvaccinated persons infected with Delta have similar levels of viral RNA and culturable virus detected, indicating that some vaccinated people infected with the Delta variant of SARS-CoV-2 may be able to transmit the virus to others.(163, 164, 177-180)

This is not an argument that shows how the unvaccinated are the PRIMARY cause, just showing that most likely, as I showed before, infected individuals are likely similarly infectious, vaccinated or not.

Okay let's keep going,

However, other studies have shown a more rapid decline in viral RNA and culturable virus in fully vaccinated people (96, 177, 180-182).

I think we just addressed this, part I, showing that only the viral load during the first 7-9 days really matters, thus this is a mute argument.

Now this is the last argument they actually provide, so it should be pretty darn convincing and good to show the unvaccinated are THE PRIMARY CAUSE of spread,

One study observed that Delta infection in fully vaccinated persons was associated with significantly less transmission to contacts than persons who were unvaccinated or partially vaccinated.(181)

Now not only does this not show a clear causal relationship between vaccination degree and spread, nor do any of their arguments, sources, nor data show such a connection. Meaning unvaccinated are definitely NOT the PRIMARY cause of spread. I'll read and go through all the methods of said paper later in full detail however for now I'll point something out that doesn't make much sense if the vaccines truly stop or significantly reduce the spread in such matter that the unvaccinated are the primary cause of the spread.

Index cases without vaccination (OR: 2.84, 95% confidence interval: 1.19, 8.45) or with one dose of vaccination (OR: 6.02, 95% confidence interval: 2.45, 18.16) were more likely to transmit infection to their contacts than those who had received 2 doses of vaccination.

We retrospectively collected information on all laboratory-confirmed symptomatic and asymptomatic cases with Delta (B.1.617.2) variant infection from the outbreak in Guangdong province in May and June 2021.

Now you would expect the unvaccinated to have a significantly higher OR(odds ratio) than those vaccinated with one dose (or two) as that should still provide a significantly higher protection against infection, especially early on (usually people get their 2nd shot within 12 weeks). Lastly the paper is based on only 167 people, making it weaker and it definitely isn't RCT (randomized controlled trial). Length of vaccination I still need to verify as I didn't keep up with China.

Last paragraph

Now let's look at what the CDC said initially again:

SARS-CoV-2 transmission between unvaccinated persons is the primary cause of continued spread.

and their conclusion now in the final paragraph:

Together, these studies suggest that vaccinated people who become infected with Delta have potential to be less infectious than infected unvaccinated people. However, more data are needed to understand how viral shedding and transmission from fully vaccinated persons are affected by SARS-CoV-2 variants, time since vaccination, and other factors, particularly as transmission dynamics may vary based on the extent of exposure to the infected vaccinated person and the setting in which the exposure occurs. Additional data collection and studies are underway to understand the extent and duration of transmissibility of Delta variant SARS-CoV-2 in the United States and other countries.

So not only do they now say vaccinated are POTENTIALLY less infectious, they completely switch gears. Nowhere in their entire explanation is there even ONE good argument nor indication that clearly links the unvaccinated as the primary cause for spread. So unless someone reads the entire page scrupulously they would never know and basically this is a form of lying.

archived CDC page just in case https://archive.md/nqZ17

1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8481107/?fbclid=IwAR1zgxjfO4mHTfOg6gqyAN8sWnXSJjEZuAlDKyKawDntZOt5ZW7hrka6v5w↩

2. https://www.whitehouse.gov/briefing-room/speeches-remarks/2021/06/02/remarks-by-president-biden-on-the-covid-19-response-and-vaccination-program/↩

3. https://doi.org/10.1056/NEJMoa2114114↩

4. News article https://westernstandardonline.com/2021/10/uk-infection-rates-for-vaccinated-overtake-the-unvaccinated-as-delta-variant-spreads/ and Uk technical report download https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1025358/Vaccine-surveillance-report-week-41.pdf↩

5. https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1009243/Technical_Briefing_20.pdf↩

6. https://www.medrxiv.org/content/10.1101/2021.07.31.21261387v4.full↩

7. https://www.cdc.gov/mmwr/volumes/70/wr/mm7031e2.htm↩

8. https://www.medrxiv.org/content/10.1101/2021.07.28.21261295v1.full-text↩

9. Fairly advanced and in depth paper https://elifesciences.org/articles/63537↩

10. https://www.pnas.org/content/118/21/e2104547118↩