Click most anywhere. My First Nations friends call Vancouver, Canada the BIG SMOKE. Hyperlinks to your own social media pages are at the bottom of each post. I am not a doctor. I am not a lawyer. I am an intelligent, scientific man with a respiratory illness. I choke in smoke and Strong Scents like VOCs - Volatile Organic Compounds, aftershave lotion and perfume, cigarette, marijuana and wildfire smoke. I win awards for photography, videography and writing.
What Makes the Delta Variant of Covid-19 So Dangerous for Unvaccinated People? It Is Everywhere.
Earthquake Drill is still happening this year!
Thursday, October 21, 2021 10:17 AM
What Makes the Delta Variant of Covid-19 So Dangerous for Unvaccinated People
A unique combination of mutations led to this more infectious version of the coronavirus, prompting revised mask guidelines
By and
SHARE
TEXT
The Delta variant of coronavirus was first detected in India last October, where it helped fuel a devastating Covid-19 surge that set records for new infections and deaths. Delta has since spread to more than 100 countries. Nations that had previously kept Covid-19 cases relatively low, such as Indonesia, Australia and parts of Africa, are now seeing record growth in infections from the more transmissible variant.
Delta was first detected in the U.S. in March and by mid-July accounted for three-quarters of Covid-19 cases. It has supplanted the Alpha variant, which until recently was the most widespread version of the virus in the U.S. Its impact is acutely felt in parts of the country with low vaccination rates, where case counts and hospitalizations are surging. The Delta variant accounts for 83% of all U.S. cases, according to recent estimates from the U.S. Centers for Disease Control and Prevention. Unvaccinated individuals make up more than 95% of all hospitalizations.
What makes the Delta variant more contagious?
Researchers think Delta is about 50% more transmissible than the Alpha variant, which means the average patient would infect 50% more contacts. Alpha itself is an estimated 50% more contagious than earlier versions of the virus.
Delta’s increased infectiousness is driven by a unique combination of mutations, changes to the virus’s genetic code that affect its structure and function. Some of Delta’s most pernicious mutations affect its spike protein, which the virus uses to latch onto and infect human cells.
These mutations can make the virus better at binding to cells, as well as help it elude antibodies, which our immune systems deploy to neutralize the virus.
Delta
is different from previous strains Highly contagious Likely more
severe Breakthrough infections may be as transmissible as
unvaccinated cases Vaccines prevent more than 90% of severe
disease, but may be less effective at preventing infection or
transmission Therefore, more breakthrough and more community
spread despite vaccination NPIs are essential to prevent
continued spread with current vaccine coverage Vaccine
breakthrough cases may reduce public confidence in vaccines
Vaccine breakthrough cases are expected Will increase as a
proportion of total cases as vaccine coverage increases Vaccine
breakthrough cases will occur more frequently in congregate
settings and in groups at risk of primary vaccine failure (i.e.,
immune compromised, elderly) Communication challenges have been
associated with increasing proportions of cases vaccinated even
when vaccine effectiveness (VE) remains stable Important to
update communications describing breakthrough cases as “rare”
or as a “small percentage” of cases 35,000 symptomatic
infections per week with 162 million vaccinated December 14, 2020
– April 10, 2021 Vaccine effectiveness against infection, 91%
among fully vaccinated; 81% for partially vaccinated 40% lower
mean RNA viral load Shorter mean duration of detectable viral RNA
(2.7 v. 8.9 days) Lower risk of febrile symptoms (25.0% v. 63.1%)
Shorter mean duration of symptoms (10.3 v. 16.7 days) Vaccine
effectiveness against hospitalization 88% No evidence of waning
immunity through 20 weeks post-2nd dose Lower estimates of VE for
mRNA vaccines among immunocompromised populations After 2 doses,
59 - 80% against infection Vaccines more effective against
hospitalization/death illness infection Delta infections
associated with higher viral load and duration of shedding India
Lower cycle threshold (Ct) values in Delta breakthrough cases
HCW, Ct 16.5 Non delta, Ct 19 Delta infection associated with
longer duration of Ct values less than 30 18 days vs. 13 days for
ancestral strains Delta variant vaccine breakthrough cases may be
as transmissible as unvaccinated cases UK, Cases down a bit today
Includes lateral flow tests
https://ourworldindata.org/coronavirushttps://coronavirus.data.gov.uk
Saturday, 31st + Friday, 30th + 29,622 Thursday, 29th + 31,117
Wednesday, 28th + 27,734 Seven days of decline
ShakeOut is still happening this year!
Thursday, October 21, 2021 10:17 AM
To a world that has become weary, yet accustomed to playing defense against SARS-CoV-2, evolution of the Delta variant is both unwelcome and unsurprising. Delta, or B.1.617.2, was first identified in India in Dec. 2020. Within a matter of months, this particular variant spread to over 98 countries around the world, becoming the dominant variant in more than a dozen of those countries, including India, the U.K., Israel and the United States. Delta is now responsible for more than 83% of COVID-19 cases being reported in the U.S. and, with only 48% of the total U.S. population fully vaccinated, conditions are ripe for continued evolution and spread of SARS-CoV-2. Three foundational questions continue to drive research with each new variant that’s identified.
1. How contagious is the Delta variant?
Scientifically accurate atomic model of coronavirus (SARS-CoV-2).
Data indicate that Delta is 40-60% more transmissible than Alpha and almost twice as transmissible as the original Wuhan strain of SARS-CoV-2. Furthermore, significantly more viral particles have been found in the airways of patients infected with the Delta variant. A Chinese study reported that viral loads in Delta infections were ~1,000 times higher than those in infections caused by other variants. In response this information, the World Health Organization (WHO) regards Delta as “the fastest and fittest” variant so far.
2. Is the Delta variant more dangerous than other variants of concern?
According to surveys conducted in the U.K., where Delta accounts for ~90% of current COVID-19 cases, symptoms of Delta tend to be a little different than other strains, but that does not necessarily mean the associated symptoms are more severe. Fever, headache, sore throat and runny nose are common, while cough and loss of smell are not. Other reports link Delta to more serious symptoms, including hearing impairment, severe gastrointestinal issues and blood clots leading to tissue death and gangrene. Research is ongoing to determine if Delta infection is associated with increased hospitalization and death. One early study assessing the risk of hospital admission in Scotland reported that hospitalization is twice as likely in unvaccinated individuals with Delta than in unvaccinated individuals with Alpha.
Case numbers and hospitalizations are once again on the rise in the U.S., especially in states where vaccination percentages are low and the Delta variant is surging. On July 16, 2021, the Centers for Disease Control and Prevention (CDC) reported a 7-day average increase in new COVID-19 cases of 69.3% and a 35% increase in hospitalizations. Still, it is difficult to determine whether Delta is actually making people sicker than previous forms of the virus or if it is simply circulating amongst more vulnerable populations where case numbers are high, vaccination rates are low and increased stress on hospital systems is impacting patient care and disease outcomes.
What is clear is that the majority of hospitalizations and COVID-19-associated deaths in the U.S. are occurring in unvaccinated people, leading to a chilling warning from CDC director Dr. Rochelle Walensky that “this is becoming a pandemic of the unvaccinated.”
3. Will vaccines remain protective against the Delta variant?
Studies show that 2 doses of vaccines are effective at preventing hospitalization and death, but neutralization levels of vaccinated sera are lower against the Delta variant compared to the original strain. A study published in the New England Journal of Medicinetested neutralization activity of sera from individuals who had recovered from natural SARS-CoV-2 infection and sera from individuals who had been fully vaccinated with Moderna or Pfizer vaccines against infectious B.1.617.2 virus. Data from the study indicated that, on average, the Delta variant was 2.9 times less susceptible to neutralization than the Wuhan strain, but most convalescent serum samples and all vaccination serum samples showed detectable neutralization activity. As a result, researchers concluded that immunity conferred by mRNA vaccines is likely to be retained against the Delta variant.
These results were supported by research, published in Nature, that evaluated the sensitivity of infectious Delta virus against monoclonal antibodies, convalescent sera and sera developed after vaccination. The study found that some antibodies targeting the N-terminal domain and receptor binding domain of the spike protein (S protein) showed impaired binding and neutralization of the Delta variant. Additionally, convalescent sera, collected up to 12 months post symptoms from individuals who had recovered from natural SAR-CoV-2 infection, were 4-fold less effective at neutralizing Delta than Alpha. Sera from individuals who were partially vaccinated (had received 1 dose of Pfizer or AstraZeneca vaccine) showed little to no neutralizing activity against Delta. Sera from 95% of those who received 2 doses of either vaccine generated a neutralizing response that was 3-5-fold less potent against Delta than Alpha.
Another study published in the New England Journal of Medicine used a test-negative, case-control design to estimate vaccine effectiveness against symptomatic disease caused by the Delta variant, compared to Alpha. The study, which was conducted in the U.K., reported an 88% efficacy against Delta after 2 doses of mRNA vaccine, but only 30.7% efficacy after 1 dose, which is below the U.S. Food and Drug Administration (FDA)’s 50% efficacy threshold for COVID-19 vaccines.
Initial reports indicated that the J&J vaccine was also effective against Delta, however a new study, not yet peer reviewed, indicated that sera from a significant fraction of J&J vaccinated individuals showed a 5-7 fold decrease in neutralizing titers, which, according to the study’s mathematical modeling, could result in decreased protection from infection.
Taken together, these data support the importance of full dose vaccination against SARS-CoV-2, but reports of reduced vaccine efficacy against Delta warrant further investigation into breakthrough infections and the possibility of vaccine booster shots. Genomic analysis of isolates from 63 vaccine breakthrough infections in India (not yet peer reviewed) revealed that B.1.617.2 was the predominant lineage in groups who were partially and fully vaccinated with either AstraZeneca or Covaxin (an inactivated virus-based vaccine developed by Bharat Biotech in collaboration with the Indian Council of Medical Research).
In late July, 2021, the CDC published a report evaluating outbreaks of SARS-CoV-2 that were associated with large public gatherings in Barnstable County, Massachusetts. Out of the 469 identified cases of COVID-19, 346 or 74% of them were breakthrough infections that occurred in people who were fully vaccinated with 2 doses of Pfizer or Moderna, or 1 dose of the J&J vaccine. Genomic analysis revealed that Delta was responsible for 90% of the 133 sequenced breakthrough infections. This information prompted the CDC to recommend the use of masks in indoor public spaces, regardless of vaccination status, in areas where COVID-19 transmission is high. Further research into breakthrough infections that occur after COVID-19 vaccination is needed.
Meanwhile, companies are already developing booster doses to improve efficacy against circulating variants. Pfizer plans to seek FDA authorization for its booster dose, which is expected to elicit stronger neutralization against the Delta variant. However, antibodies alone do not give the whole picture of immune protection. How other vaccine-elicited immune components, such as T cells and B cells, respond when challenged by the Delta variant is still relatively unclear, and conversation about whether booster doses are needed yet are ongoing.
Culpable Mutations of the Delta Variant
Amino acid changes to the spike (S) protein in SARS-CoV-2 variants of concern (VOCs).
Source: American Society for Microbiology
Without a doubt, increased transmissibility, coupled with potential increases in disease severity and immune escape, makes Delta especially dangerous. The SARS-CoV-2 spike protein is the main target of COVID-19 vaccines, and most serum neutralizing antibody responses elicited during natural SARS-CoV-2 infection are directed at the receptor binding domain (RBD) of S protein. Therefore, if a mutation (or combination of mutations) causes changes to the S protein that are not recognized by first wave antibodies, immunity developed against the reference strain may be ineffective against the new variant. The SARS-CoV-2 Delta variant possesses a combination of S gene mutations that make it particularly worrisome to scientists, including multiple mutations in the receptor binding domain (RBD), a mutation located near the furin cleavage site and a number of mutations in a vulnerable region of the N-terminal domain known as an “antigenic supersite.”
Receptor Binding Domain
The receptor binding domain is the portion of the spike protein that binds directly to human ACE2 receptors. Delta has 3 RBD mutations. The first, a lysine to asparagine substitution at position 417, is present in some, but not all sequences of B.1.617.2. It is also common to the Beta variant and has been associated with conformational changes to S protein, which may aid in immune escape. The second mutation, a leucine to arginine substitution at position 452, is common to the former variant of interest Epsilon, and is known to increase affinity for ACE2 receptors found on the surface of a variety of human cells, including the lungs. And the third, a threonine to lysine substitution at position 478, is common to the B.1.1.519 lineage, and has been predicted to increase electrostatic potential and steric hindrance, which may further increase RBD/ACE2 binding affinity and enable immune escape.
Furin Cleavage Site
The spike protein consists of a receptor-binding subunit (S1) and a fusion subunit (S2), which must be cleaved from each other to mediate membrane fusion and cause infection. The furin cleavage site is the junction where that cleavage takes place, and Delta contains a proline to arginine substitution (also common to Alpha) near this cleavage site at position 681 that makes the sequence less acidic and causes furin to recognize and cut more effectively. As a result, more spike proteins are primed to enter human cells. Research indicates that less than 10% of spike proteins are primed in the original strain, 50% are primed in Alpha and greater than 75% are primed in Delta. The mutation likely increases viral infectivity and transmissibility; however, it must occur on the background of additional spike protein mutations in order to be consequential.
NTD-Antigenic Supersite
Scientists have identified regions in the N-terminal domain of S protein that are especially vulnerable to antibody recognition and attack, called NTD-antigenic supersites. Delta contains a number of mutations that fall within an antigenic supersite, including a threonine to arginine substitution at position 19, a glycine to aspartate substitution at position 142, deletions at positions 156 and 157 and an arginine to glycine substitution at position 158. Accumulated mutations in antigenic supersites are thought to enhance the virus’s ability to avoid immune detection.
Amino acid changes to the spike (S) protein in the Delta variant.
Source: American Society for Microbiology
Stopping Transmission is Key to Controlling Variants
Humanity has its hands full as the virus continues to mutate and evolve potential mechanisms to escape the immune defenses its hosts have worked so hard and sacrificed so much to develop. In addition to the variants of concern currently being monitored, researchers are keeping an eye on a number of variants of interest, including Lambda. When specific mutations (like K417N/T) become fixed in different virus lineages, it is evidence that natural selection may be occurring. According to Dr. Vaughn Cooper, ASM’s Council on Microbial Sciences-elected Board Director and evolutionary biologist, stopping the virus is key. “The more infections, the more chance that mutations will occur and thus the more likely selection will enrich the best mutations to improve the virus,” he explained. Vaccination is the best weapon in the fight to curb transmission.
There
is growing concern about a fourth wave of COVID-19 as cases start to
climb again across much of Canada, with the increase being
overwhelmingly driven by unvaccinated people in western provinces.
Watch The National live on YouTube Sunday-Friday at 9 p.m. ET
Subscribe to The National: https://www.youtube.com/user/CBCTheNa...
Connect with The National online: Facebook |
https://www.facebook.com/thenational
Twitter | https://twitter.com/CBCTheNational
Instagram | https://www.instagram.com/cbcthenational
More from CBC News | https://www.cbc.ca/news
The National is CBC's flagship nightly news program, featuring the
day's top stories with in-depth and original journalism, with hosts
Adrienne Arsenault and Andrew Chang in Toronto, Ian Hanomansing in
Vancouver and the CBC's chief political correspondent, Rosemary
Barton in Ottawa.
The
latest surge of COVID-19 cases in the U.S. is mostly in the
unvaccinated, especially children who aren’t eligible. With school
about to begin, there is debate about how to protect them. Watch The
National live on YouTube Sunday-Friday at 9 p.m. ET Subscribe to The
National: https://www.youtube.com/user/CBCTheNa...
Connect with The National online: Facebook |
https://www.facebook.com/thenational
Twitter | https://twitter.com/CBCTheNational
Instagram | https://www.instagram.com/cbcthenational
More from CBC News | https://www.cbc.ca/news
The National is CBC's flagship nightly news program, featuring the
day's top stories with in-depth and original journalism, with hosts
Adrienne Arsenault and Andrew Chang in Toronto, Ian Hanomansing in
Vancouver and the CBC's chief political correspondent, Rosemary
Barton in Ottawa.
Delta
Variant is Different - It's the NEW COVID Delta Variant COVID
SARS-CoV-2 Delta variant, also known as lineage B.1.617.2, is a
variant of lineage B.1.617 of SARS-CoV-2, which causes COVID. It was
first detected in India in late 2020. The World Health Organization
(WHO) named it the Delta variant on 31 May 2021. What’s different
about DELTA Variant Patients? The delta variant is almost like a
whole new COVID virus, as it behaves very differently from the
previous COVID strains. It has at least three mutations on its spike
protein, and more specifically, on its receptor-binding domain.
That’s the part of the spike protein that binds to the ACE2
receptor on the cells in your body. The delta variant’s mutations
help it bind more efficiently to the ACE2 receptor and allow the
virus to enter the cell more easily. Also, its mutations allow it to
better evade the body’s immune system.
---------------------------------------------------------- Want more
health tips from me? https://doctormikehansen.com/
Want to increase your energy?
https://doctormikehansen.com/more-ene...
---------------------------------------------------------- Timestamps
⏩ 00:00
COVID Delta Variant Explained 00:29
Delta Variant USA Update 00:39
Is the Delta Variant more Contagious than other Variants? 01:03
Fully vaccinated people can still spread the delta variant and be
infected by it. 01:56
Does The Delta Variant Make Unvaccinated People More Prone to Dying?
02:35
COVID Breakthrough Cases 03:41
Unvaccinated patients regret not getting vaccinated 05:55
Covid Vaccine Update in the US 06:45
Vaccine Hesitancy 07:56
What Hospitals are using to treat covid? 08:22
Covid Vaccine Infertility 08:38
Covid Vaccine Pregnancy 09:09
Medical Exemption of Not Getting COVID Vaccines The delta variant has
caused COVID cases in the USA to rise over 300% over the past month,
along with similar increases in hospitalizations and deaths. The
Delta variant is estimated to be at least 60% more transmissible. One
CDC document suggests the Delta variant is about as transmissible as
chickenpox -- with each infected person infecting, on average, 8 or 9
other people. Compare that to the original strain of COVID, which was
about as contagious as the common cold, with each infected person
infecting two others, on average. Studies on people infected with
delta variant showed that the fully vaccinated had as much virus in
their bodies as unvaccinated people did. That doesn’t mean worse
infection, though, if you’re vaccinated. But what the significance
of those high viral loads leads to the higher transmission of the
virus, vaccinated or not. Even if they don’t have symptoms. It's
why the CDC says that even vaccinated people should wear masks in
areas of sustained or high transmission. Also, a study in China found
that the viral loads of people infected with Delta were 1,000 times
higher than people infected at the beginning of the pandemic, and
delta transmits in four days, compared to six days for the original
strain. Three somewhat older studies from Canada, Singapore, and
Scotland show that people infected with the Delta variant are more
likely to end up in the hospital. Does it make unvaccinated people
more prone to death compared to the original strain? Hard to know
since there are currently no studies showing that one way or another.
It’s also trickier to answer this question because you’re
comparing apples to oranges. You’re comparing different strains
with the original strain; no one was vaccinated in 2020. Also, at the
beginning of the covid pandemic, we weren’t using things like
dexamethasone and tocilizumab, two drugs that we now use to treat
COVID, because we now know they reduce mortality. With the mRNA
vaccines we have, they are about 95% effective at preventing serious
COVID illness. So we know that even before the delta covid variant
emerged, there will be breakthrough cases. The CDC released a study
examining an outbreak in Massachusetts where 74% of people who got
infected had been fully vaccinated -- and four of them ended up in
the hospital. Testing showed that the Delta variant made up 90% of
those cases. But overall, still, MOST of the virus is spread by
unvaccinated people. The CDC reported a total of 6,587 breakthrough
cases, including 6,239 hospitalizations and 1,263 deaths as of July
26. At that time, more than 163 million people in the US were fully
vaccinated against Covid. But here is pretty impressive. STAT: Less
than 0.004% of people who have been fully vaccinated experienced
breakthrough infections resulting in hospitalization, and less than
0.001% have died from the disease. Doctor Mike Hansen, MD Internal
Medicine | Pulmonary Disease | Critical Care Medicine Website:
https://doctormikehansen.com/
IG Account: http://instagram.com/doctor.hansen/
FB Page: https://www.facebook.com/DoctorMikeHa...#deltavariant#covid#covidvariant
