How COVID spreads:
This video discusses the transmissibility of COVID 19 on airplanes- do masks help?
COVID-19 most contagious in first 5 days of illness, study finds
This article reports on a study published in The Lancet
medical journal that found that people with COVID 19 infections were
most contagious during the first 5 days after developing symptoms. The
study also looked at viral load and viral shedding.
Community
and Close Contact Exposures Associated with COVID-19 Among Symptomatic
Adults ≥18 Years in 11 Outpatient Health Care Facilities — United
States, July 2020
"Findings from a case-control investigation
of symptomatic outpatients from 11 U.S. health care facilities found
that close contact with persons with known COVID-19 or going to
locations that offer on-site eating and drinking options were associated
with COVID-19 positivity. Adults with positive SARS-CoV-2 test results
were approximately twice as likely to have reported dining at a
restaurant than were those with negative SARS-CoV-2 test results."
Omicron:
Classification of Omicron (B.1.1.529): SARS-CoV-2 Variant of Concern
Omicron - How does a variant become dominant?
Primary symptoms of Omicron
include tiredness, headaches, muscle and body pain, and sometimes a
sore throat. Fewer sick people seem to be seeking care. Lateral flow
tests don't appear to work on the first day, but do work until the end
of 5 days from symptom onset. The omicron variant is replacing the
delta variant. Approximately 75% of hospitalized patients were admitted
for other reasons and the COVID finding is incidental. The omicron
variant seems to have incorporated a gene from another coronavirus that
causes the common cold, which appears to be contributing to omicron
being more transmissable but less virulent. Pfizer is claiming that
their vaccine is effective against omicron for those who have had 3
doses, and still mostly effective for those who've had 2, but they
aren't releasing the actual data. This is only looking at antibody
levels (titers) but not t-cells which are arguably more significant.
Omicron Found Mostly in Vaccinated Americans So Far (12/12/2021)
"Through the first week of this month, the CDC had confirmed a total of
43 cases of Omicron in the U.S. Thirty-four, or nearly 80 percent, of
those cases involved fully vaccinated individuals—14 of whom had also
received booster shots. Twenty-five of those infected with the virus
were between the ages of 18 and 39, and 10 of the cases were among
adults 40 to 64 years old, while four cases were children and four were
seniors. Nearly all the Omicron cases were said to be mild, with
symptoms such as coughing, congestion and fatigue. Only one of the cases
required hospitalization. There were no deaths."
"Preliminary data on Omicron also suggests that the virus may be resistant to COVID vaccines. A recent study conducted by researchers at the Africa Health Research Institute in South Africa shows that Omicron “significantly reduces antibodies” generated by Pfizer/BioNTech’s experimental messenger RNA (mRNA) BNT162b2 biologic. The researchers found a 41-fold reduction in the ability of the antibodies to neutralize the Omicron variant compared with the original SARS-CoV-2 virus.
“We seem to see a drastic reduction in neutralizing activity, far more
than with previous variants,” said virologist Florian Krammer, PhD of
the Icahn School of Medicine at Mount Sinai, New York. “Little activity
was left in vaccinated individuals.”
Did Omicron catch a Cold? Unique mutation found in the Omicron variant Layman explanation
Preliminary outcome data from South Africa
Unvaccinated
people are getting sicker than vaccinated ones, but still cases are
mild. So far there is no need for oxygen, average hospital stay has
decreased from 8.5 days to 2.8 days, no COVID-related death in the
previous 2 weeks in children.
Plasma Neutralization of the SARS-CoV-2 Omicron Variant
"Although these findings indicate that the omicron variant shows an
unprecedented degree of neutralizing antibody escape, they also suggest
that boosting and promoting affinity maturation of antibodies in persons
who have previously been infected or vaccinated,
with the use of existing Wuhan-hu-1–based vaccine immunogens, will
provide additional protection against infection with the omicron variant
and subsequent disease."
Can the Omicron BA.2 be the end? Transmissibility, Immunity Escape, Natural Immunity & Severity
Earlier Variants
SARS-CoV-2 variants D614G, B.1.1.7 (alpha), B.1.617.1 (kappa), B.1.617.2
(delta), P.1 (gamma), B.1.429 (epsilon), and B.1.351 (beta).
Tracking the Mutations of the SARS-CoV-2 Virus
"As is the nature of viruses, the SARS-CoV-2 virus that causes COVID-19
disease symptoms continues to mutate. Some scientists estimate it
evolves at a rate of two new mutations every month, although most
changes are minor and considered clinically unimportant."
This
article goes on to explain the naming system used for variants of the
SARS CoV 2 virus based on the Greek alphabet. It makes the point that
naming a variant based on the region or country where it was first found
creates problems for that area and people whose ancestry is from that
area, resulting in economic hardship, and hate crimes to name a few.
Additionally variants do not necessarily originate in the same place
where they are first found.
"The first four SARS-CoV-2 variants to fall under the new guidelines are
those originally referred to as the U.K./Kent (B.1.1.7), South Africa
(B.1.351), Brazil (P.1) and India (B.1.617.2) variants, hereafter
referred to as the Alpha, Beta, Gamma, and Delta variants, respectively,
following in order of detection.
Two variants first identified in the U.S. (B.1.427/429 and B.1.526)
were quickly dubbed Epsilon and Iota, respectively. New variants are
expected to adhere to the same system of using the Greek alphabet."
Neutralization of the SARS-CoV-2 Mu Variant by Convalescent and Vaccine Serum
SARS-CoV-2 May Have Another Door Into Cells |
Evidence suggests that the virus SARS Cov 2 can enter cells through the
receptor ACE2, which has been known for awhile, but may also be able to
enter through another protein called CD 147 (Cluster of Differentiation
147). It is also called Emmprin, M6, or Basigin). Many other viruses,
including measles, HIV, and the original SARS COV virus can also use
this protein to enter and infect cells. This receptor is involved in
cellular communication and coordination so it is found on many kinds of
cells in many body systems. Production of CD147 increases when blood
sugar is high which might explain why people with diabetes have a higher
risk from COVID. Research so far shows that CD147 is also more
commonly expressed in people with asthma, obesity, COPD, and
hypertension. This may also explain some skin rashes and blood clotting
that seem to be symptoms of some COVID infections. Antibodies,
including those for COVID, can stick to red blood cells and make them
"sticky" and prone to clotting. Red blood cells don't have ACE2
receptors but they do have CD147 receptors (this is the same receptor
that malaria parasites use to get into them). Endothelial cells also
express CD147 and this might explain how the virus causes high blood
pressure. A medication called Meplazumab binds to CD147 so that viruses
can't use it and preliminary research sows that this drug helps reduce
the severity of COVID infection. The antibiotic Azithromycin also seems
to block the CD147 receptor and is also used to treat malaria, so maybe
it will be an effective option?
High infection rates can lead to more variants because more infections means more opportunities for the virus to mutate. Increased mutations can lead to variants of the virus that are more transmissible, more deadly, and less responsive to vaccines. The variant in Brazil is spreading despite the fact that about 75% of the population had been exposed to the virus previously, which could mean that either immunity doesn't last long or that the virus has mutated enough that it can evade the antibodies. mRNA vaccines can be updated to target the new variants in as little as 6 weeks. A researcher explains that every new infection of the coronavirus is an opportunity for it to mutate and some of these mutations will make it more virulent, more transmissible, and/or more deadly. Limiting transmission of infections reduces the possibility that mutated strains will be passed on and spread. It is not known how much, if at all, vaccination will prevent or reduce transmission of the virus. The vaccine trials conducted so far (as of January 2021) did not investigate whether the vaccines led to what is called "sterilizing immunity", which is when a pathogen can't reproduce enough in a person to shed enough to be able to infect others. This can happen if a person's immune response to the pathogen is so fast and effective that the pathogen can't gain a foothold and is eliminated.
How British Scientists Found the More Infectious Coronavirus Variant
"One
mutation the patient had, labeled 69-70del, changes the shape of the
spike protein. Another, N501Y, can help the protein bind more tightly to
human cells."
"Eventually, British scientists detected 23
mutations that distinguished these genomes from the earliest known
version in Wuhan, China — enough to be a considered a new variant, since
labeled B.1.1.7.""The variant is now estimated to account for more than
80 percent of positive cases in London and at least a quarter of
infections elsewhere in England, and has turned up in more than 50
countries." (from Jan 22, 2021)
A New COVID 19 Variant is Spreading in Europe
As
many European countries are fighting a second wave of COVID cases, a
new variant of the SARS Cov 2 virus has been found to be active in some
(but not all) of these new rising numbers. It seems to have originated
in Spain and traveled quickly throughout Europe. It seems to spread very
effectively (possibly moreso than the original variant) and is now the
dominant variant in some countries. We are being told that this won't
change the effectiveness of a vaccine if/when one is introduced, or that
the illness caused by this variant is any different.
Vaccine Breakthrough Infections with SARS-CoV-2 Variants
"These observations indicate a potential risk of illness after successful
vaccination and subsequent infection with variant virus, and they
provide support for continued efforts to prevent and diagnose infection
and to characterize variants in vaccinated persons. (Funded by the
National Institutes of Health and others.)"
Viral Dynamics of SARS-CoV-2 Variants in Vaccinated and Unvaccinated Persons
