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Old 19-11-2020, 08:27   #151
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Re: Science & Technology News

AstraZeneca and Oxford University's potential COVID-19 vaccine [called AZD1222 or ChAdOx1 nCoV-19] produced a strong immune response in older adults, data published on Thursday showed, with researchers expecting to release late-stage trial results by Christmas. Late-stage, or Phase III, trials are ongoing to confirm the findings, researchers said, and to test whether the vaccine protects against infection with SARS-CoV-2 in a broad range of people, including people with underlying health conditions.
Unlike the Pfizer-BioNTech and Moderna shots, both of which use new technology known as messenger RNA (mRNA), AstraZeneca's is a viral vector vaccine made from a weakened version of a common cold virus found in chimpanzees.
This vaccine could be easier to roll out because it doesn't need to be stored at very cold temperatures.

“Safety and immunogenicity of ChAdOx1 nCoV-19 vaccine administered in a prime-boost regimen in young and old adults (COV002): a single-blind, randomised, controlled, phase 2/3 trial” ~ by Maheshi N Ramasamy, et al
“ ... We have reported the immunogenicity of a novel chimpanzee adenovirus-vectored vaccine, ChAdOx1 nCoV-19, in young adults, and now describe the safety and immunogenicity of this vaccine in a wider range of participants, including adults aged 70 years and older...”
https://www.thelancet.com/journals/l...466-1/fulltext

Oxford vaccine shows 'encouraging' immune response in older adults
https://www.bbc.com/news/health-54993652
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Old 20-11-2020, 10:00   #152
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Re: Science & Technology News

Regular HEPA filters are fantastic at capturing particles (Virions) under 0.3 microns.
The SARS-CoV-2 virus (that causes Covid-19) particle size is about 125 nanometers (60–140 μm), or about 0.125 microns (0.06 microns to 0.14 microns). Microns are small –1 millionth of a meter.
Bacteria are often about 1 micron. Pollen particles are often 10 microns or bigger.
N95 mask packaging typically has a label (or verbiage) indicating protection down to 0.3 microns.

The virus attaches to water droplets, or aerosols (i.e. really small droplets) that are generated by breathing, talking, coughing, etc. These consist of water, mucus protein, and other biological material, and are all about 1 micron (or larger).

It seems counterintuitive that 0.3 micron particles would be harder to capture than 0.01 microns (30 times smaller), but smaller particles, like 0.01-micron particles, are even easier to capture than 0.3 micron particles.

That is because we think of filters like a net, thinking that if a particle is smaller than the holes in the net, it gets through. That is how HEPA filtres, or N95 masks, work for particles >0.3 microns. These particles either cannot fit through, either because they are bigger than the filter hole size, or their inertia causes them to hit the filter fibers (impaction & interception).
Depending on the size of the particle, some are more likely to travel in straight lines (their inertial path) and others (smaller), through Brownian motion (scattered, haphazard motion due to redirection from encountering air molecules).

Particles under 0.3 microns have so little mass the actually bounce around like pinballs when they hit gas (O2 & N) molecules, so they move in random zigzag patterns, known as Brownian Motion.

For those particles that are 0.1 µm and smaller, diffusion is regarded as an effective filtration mechanism.
Brownian motion, the process by which the constant motion of oxygen/nitrogen molecules causes collisions between particles—results in a “wandering” pathway. The complex path that is followed by the small particles, increases the chance that they will collide with the filtre fibre, and remain there.

Here’s why that 0.3 micron number comes up all the time. The weirdness of Brownian motion happens under 0.3 microns. The more easily understandable filtering occurs above 0.3 microns. But where those two processes overlap is the weak spot.
Particles at 0.3 microns lie in between the two, and that makes them the hardest particle size to capture. Researchers call this the most penetrating particle size (MPPS).The theory of 0.3 microns being hardest to capture works for fiber filters of all types, including N95 masks, and HEPA filtres.

The 0.3 micron masks & filtres are actually best for particles, either larger or smaller, than that 0.3 micron threshold.

Some articles, on the subject:

“Submicron and Nanoparticulate Matter Removal by HEPA-Rated Media Filters and Packed Beds of Granular Materials” ~ by J.L. Perry et al
This NASA study of HEPA filtration is quite technical, but the graph on page 7, and the preceding paragrap,h do a good job of explaining why HEPA filters are actually most efficient (almost 100% at 0.01 micron) at capturing ultrafine particles below the 0.3-micron HEPA test standard.
https://ntrs.nasa.gov/api/citations/...0170005166.pdf

“Filtration Mechanisms of Particulate Respirators” ~ By Erik Johnson (3M)
https://multimedia.3m.com/mws/media/...espirators.pdf

“Numerical simulation of virus diffusion in facemask during breathing cycles” ~ by Li Yi, Li Fengzhi, and Zhu Qingyong
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7094236/

Cloth masks are a worthy line of defense to mitigate COVID-19 pandemic” ~ by Christine Lewis
Sarah Arrowsmith, a scientist and lab coordinator with the Arizona State University Biodesign Swette Center for Environmental Biotechnology, looked at a 2013 publication, that studied the effectiveness of cloth masks against viral particles, and was convinced that homemade masks could work. So, she made a pattern, pulled out some cloth and constructed some masks on her own.
https://biodesign.asu.edu/news/cloth...id-19-pandemic

“Testing the Efficacy of Homemade Masks: Would They Protect in an Influenza Pandemic?” ~ by Anna Davies et al
This study (referenced above) examined homemade masks as an alternative to commercial face masks. Both masks significantly reduced the number of microorganisms expelled by volunteers, although the surgical mask was 3 times more effective in blocking transmission than the homemade mask.
https://www.researchgate.net/publica...uenza_Pandemic
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Old 21-11-2020, 04:41   #153
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Re: Science & Technology News

Sentinel-6 Michael Freilich

A satellite, jointly developed by Europe and the United States, is being launched (from Vandenberg AFB, aboard a SpaceX Falcon 9) this weekend, which will greatly help scientists keep track of the rise in global sea levels.

The new satellite, called Sentinel-6 Michael Freilich, contains cutting-edge instruments able to capture sea level height with unprecedented accuracy, adding to space-based measurements going back almost 30 years.
Europe and the United States are sharing the 900-million-euro ($1.1-billion US) cost of the 10-year mission, which includes the launch of an identical twin called Sentinel-6B in 2025.

While sea level measurements are also taken at ground level, in harbours and other coastal areas, they don't provide the same precise uniform standard and breadth as data collected by a single satellite, sweeping the entire globe every ten days.
If you measure it at sea level, you have one measurement device in Amsterdam, and you have a different one in Bangkok, and yet another one in Miami. But with a satellite, you can compare these measurements globally, because it's the same instrument that flies over all these areas.

Other instruments on board will measure how radio signals pass through the atmosphere, providing data on atmospheric temperature and humidity that can help improve global weather forecasts.

More ➥
https://www.nasa.gov/feature/jpl/sen...red-for-launch

And ➥ ESA - Sentinel-6

Watch the Launch of the Ocean-Observing Sentinel-6 Michael Freilich Satellite (11:45 AM ET)
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Old 21-11-2020, 18:54   #154
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Re: Science & Technology News

Quote:
Originally Posted by GordMay View Post
Sentinel-6 Michael Freilich

A satellite, jointly developed by Europe and the United States, is being launched (from Vandenberg AFB, aboard a SpaceX Falcon 9) this weekend, which will greatly help scientists keep track of the rise in global sea levels.

The new satellite, called Sentinel-6 Michael Freilich, contains cutting-edge instruments able to capture sea level height with unprecedented accuracy, adding to space-based measurements going back almost 30 years.
Europe and the United States are sharing the 900-million-euro ($1.1-billion US) cost of the 10-year mission, which includes the launch of an identical twin called Sentinel-6B in 2025.

While sea level measurements are also taken at ground level, in harbours and other coastal areas, they don't provide the same precise uniform standard and breadth as data collected by a single satellite, sweeping the entire globe every ten days.
If you measure it at sea level, you have one measurement device in Amsterdam, and you have a different one in Bangkok, and yet another one in Miami. But with a satellite, you can compare these measurements globally, because it's the same instrument that flies over all these areas.

Other instruments on board will measure how radio signals pass through the atmosphere, providing data on atmospheric temperature and humidity that can help improve global weather forecasts.

More ➥
https://www.nasa.gov/feature/jpl/sen...red-for-launch

And ➥ ESA - Sentinel-6

Watch the Launch of the Ocean-Observing Sentinel-6 Michael Freilich Satellite (11:45 AM ET)
Are the sensor specifications and processing software for all the satellites devices being made freely available to the public?
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Old 22-11-2020, 08:47   #155
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Re: Science & Technology News

AZD7442 Potential Prophylactic & Therapeutic Treatment

AstraZeneca has started late-stage (Phase 3) trials of it’s experimental long-acting monoclonal antibody combination (cocktail) drug (AZD7442) it hopes could be used as a so-called prophylactic, to prevent COVID-19 infection, in at-risk people, for up to 12 months.
The prophylactic treatment differs from a vaccine, in that it introduces (2) monoclonal antibodies, rather than prompting the body's immune system to make them. It may prove useful, in people whose immune systems are weaker or compromised, and who don't respond to vaccination.
Monoclonal antibodies mimic natural antibodies that the body generates to fight off infection. They can be synthesized in the laboratory and are already used to treat some types of cancer.
AZD7442 has the potential, both, to treat and prevent disease progression in patients already infected with the SARS-CoV-2 virus, and to be given, as a preventative medication, prior to people being exposed to the virus.
Separately, AstraZeneca is developing a COVID-19 vaccine, in conjunction with researchers at Oxford University.
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Old 22-11-2020, 08:59   #156
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Re: Science & Technology News

Quote:
Originally Posted by RaymondR View Post
Are the sensor specifications and processing software for all the satellites devices being made freely available to the public?
What - you want to build your own?

Sentinel-6 will provide measurements of sea surface height, significant wave height, and wind speed without degradation in precision and accuracy compared to the currently flying Jason-2 mission.

In addition to the altimeter data service, Sentinel-6 will also include a GNSS-RO (GNSS Radio Occultation) instrument as a secondary payload, taking advantage of the non-sun-synchronous orbit of Sentinel-6. The GNSS-RO measurements will provide information on atmospheric pressure, temperature and water vapor as well as ionospheric data. The radio occultation data service primarily addresses the needs of meteorological and climate users.

The Sentinel-6 Space Segment consists of two successive Jason-CS satellites (A and B), based on the CryoSat-2 heritage platform, with some tailoring to specific needs of the Sentinel-6 mission.

The satellites will embark the following main payload:

• A radar altimeter (Poseidon-4), to measure the range between the satellite and the mean ocean surface, determine significant wave height and wind speed, and provide the correction for the altimeter range path delay in the ionosphere by using signals at two distinct frequencies (Ku-band and C-band).
THE CEOS DATABASE : INSTRUMENT SUMMARY - Poseidon-4 Altimeter

• A microwave radiometer, called AMR-C (Advanced Microwave Radiometer-C) of JPL, to provide a correction for the wet tropospheric path delay for the altimeter range measurement.
https://www.nrao.edu/meetings/isstt/...2017000034.pdf

• POD (Precise Orbit Determination) instruments – namely a GNSS (Global Navigation Satellite System) and precise orbit determination receiver (GNSS-POD), a DORIS (Doppler Orbitography and Radiopositioning Integrated by Satellite) instrument, and a LRA (Laser Retroreflector Array) – to provide with high accuracy and precision a measurement of the orbital position as needed for the conversion of the measurement of altimeter range into a sea level.

• GNSS-RO (GNSS- Radio Occultation) instrument to provide (with high vertical resolution) all-weather atmospheric and ionospheric soundings by tracking GNSS satellites.

The GNSS-RO instrument is added to Sentinel-6 as a secondary mission to provide radio occultation observation services to meteorological users. However, the primary altimeter mission supported by the other instruments takes priority in all design and mission planning.

It is important to remark that the Poseidon-4 radar altimeter has evolved significantly from the Poseidon-3A and -3B instruments on board Jason-2 and -3, respectively. In addition to a conventional pulse-width limited processing, also known as low-resolution mode, the Poseidon-4 on board the Jason-CS satellites will also have the facility of simultaneous high-resolution (HR) processing, generally referred to as SAR (Synthetic Aperture Radar) mode processing. This HR processing will provide further service alignment with the SAR mode of the Sentinel-3 SRAL mission.

The Jason-CS satellites will fly in the same orbit as their predecessors, TOPEX/Poseidon and the Jason missions (Table 4). This is a non-sun-synchronous orbit with a nominal altitude of 1336 km and 66ş inclination. The orbit period is 112 min and 26 s and the ground track cycle repeats approximately every 9 days and 22 hours. Because of the relatively large ground track spacing of 315 km at the equator, Jason-CS alone will not be able to satisfy the sampling requirements for mesoscale oceanography. Thus, the Sentinel-6 mission is coordinated with other altimeter missions, chiefly the Sentinel-3 mission, to provide together a complementary spatiotemporal sampling of the oceans and serve as a high-precision reference to sea-level-change studies.


An over-view of Sentinel-6 Michael Freilich Spacecraft & Instruments
https://www.jpl.nasa.gov/news/press_...on/spacecraft/

The Sentinel Online technical website allows you to find all information you need regarding the Sentinel Missions
Data Products ➥ https://sentinel.esa.int/web/sentine...Fdata-products

According to Airbus (the builder), Huld is responsible for the Independent Software Verification and Validation of the satellite
https://huld.io/references/huld-ensu...in-sea-levels/


I imagine (but can't be bothered to confirm) that the software, used to analyze the raw data provided by Sentinel-6, will depend upon the researchers doing that work.
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Old 23-11-2020, 04:41   #157
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Re: Science & Technology News

Covid pandemic has had little impact on rise in CO2
The global response to the Covid-19 crisis has had little impact, on the continued rise in atmospheric concentrations of CO2, says the World Meteorological Organization (WMO).
Carbon emissions fell dramatically in 2020, due to "lockdowns", that saw transport and industry grind to a halt.
But this has only marginally slowed down the overall rise in concentrations, the scientists say.
Greenhouse gas concentrations are the cumulative result of past and present emissions of a range of substances, including carbon dioxide, methane and nitrous oxide.
According to the WMO, the global average in 2019 was 410.5ppm, an increase of 2.6ppm over 2018. This was larger than the increase from 2017 to 2018, and bigger than the average over the past decade.
Thanks to "lockdowns", in early 2020, carbon emissions fell by 17%, at their peak, but the overall effect on concentrations has been very small. Preliminary estimates suggest that CO2 will continue to increase this year, but that rise will be reduced by 0.08 to 0.23ppm.
This falls within the 1ppm natural variability, that occurs from year to year. Meteorologists expect CO2 levels to vary by 1ppm, between years, due to natural fluctuations in the climate (for reasons other than human releases of carbon). The WMO expects CO2 to fall by 0.08-0.23ppm in 2020, which is less than the 1ppm due to natural variability.
While there isn't an overall figure for 2020 concentrations, individual monitoring stations show that the rise has continued this year despite the pandemic.
Monthly average CO2 concentrations at Mauna Loa in Hawaii - a key atmospheric monitoring station, where carbon dioxide data is gathered - were 411.29ppm in September 2020, up from 408.54 the previous year.
Similarly, at Cape Grim in Tasmania, another key air pollution measurement station, September 2020 saw CO2 concentrations reach 410.8ppm - up from 408.58 in 2019.
The details are published in the WMO's annual greenhouse gas bulletin.

WMO Greenhouse Gas Bulletin (GHG Bulletin) - No. 16 (23 November 2020)
Can we see the impact of COVID-19 confinement measures on CO2 levels in the atmosphere?
https://library.wmo.int/doc_num.php?explnum_id=10418
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Old 23-11-2020, 06:06   #158
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Re: Science & Technology News

US Breaking Records

As new cases spike, hospitalization rates have followed. At least 83,870 Covid-19 patients were hospitalized Sunday (Nov 22), the 13th straight day the US has broken its hospitalization record, and the 20th day in a row, of more than 100,000 new cases, according to the Covid Tracking Project. [1]
[1] ➥ https://covidtracking.com/data
https://twitter.com/COVID19Tracking/...68509257363457


On Friday, the CDC said [2] that 50% of cases are spread by people without symptoms.

This means at least half of new infections come from people likely unaware they are infectious to others.
With these assumptions, 59% of infections would be transmitted when no symptoms are present, but could range (from) 51%-70% if the fraction of asymptomatic infections were 24%-30%, and peak infectiousness ranged 4-6 days."
It cited a study published, in July, in the Proceedings of the National Academy of Sciences [3], and as-yet unpublished CDC data.

Scientific Brief: Community Use of Cloth Masks to Control the Spread of SARS-CoV-2 (Nov. 20/20)
"... Masks are primarily intended to reduce the emission of virus-laden droplets (“source control”), which is especially relevant for asymptomatic or presymptomatic infected wearers who feel well and may be unaware of their infectiousness to others, and who are estimated to account for more than 50% of transmissions. Masks also help reduce inhalation of these droplets by the wearer (“filtration for personal protection”).
The community benefit of masking for SARS-CoV-2 control is due to the combination of these effects; individual prevention benefit increases with increasing numbers of people using masks consistently and correctly ..."
[2] “Community Use of Cloth Masks to Control the Spread of SARS-CoV-2"
https://www.cdc.gov/coronavirus/2019...sars-cov2.html

[3] “The implications of silent transmission for the control of COVID-19 outbreaks” ~ by Seyed M. Moghadas et al
https://www.pnas.org/content/117/30/17513
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Old 23-11-2020, 06:58   #159
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Re: Science & Technology News

The futuristic cargo ship made of wood

In a small, rustic shipyard on the Pacific coast of Costa Rica, a small team is building what they say will be the world’s largest ocean-going clean cargo ship. Made largely of timber, Ceiba combines both very old and very new technology: sailing masts stand alongside solar panels, a uniquely designed electric engine and batteries. Once on the water, she will be capable of crossing oceans entirely without the use of fossil fuels.

Ceiba has a regenerative engine: when she is travelling using her sails, her propellers can be used as underwater turbines to capture excess energy, similar to how regeneration mode in an electric car can capture excess kinetic energy when you brake. The electricity, along with that generated by the solar panels, can then be stored in the battery until it is needed to drive the ship. Importantly, and unlike many other ships that already use some kind of electrical engine, Ceiba’s engine is purely electric and does not have diesel as a back-up option. She is genuinely fossil free.

She will carry around nine standard shipping containers. The largest conventional container ships today carry more than 20,000 containers. And while Ceiba is small compared to most container ships, she is still around 10 times larger than the most established fossil-free sailing cargo vessel currently in service, the Tres Hombres.

Companies are willing to pay a premium for emissions-free transport of products such as green coffee, cacao, organic cotton and turmeric oil. Bio-packaging, electric bicycles and premium barley and hops for Costa Rica’s burgeoning craft-beer market are among bookings so far on the southbound journeys.

Plans are she will begin transporting cargo between Costa Rica and Canada by 2022.
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Old 23-11-2020, 10:21   #160
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Re: Science & Technology News

"Wear a mask to slow the spread."

Mask Mandates Work To Slow Spread Of Coronavirus, Kansas Study Finds

On Friday Nov 20, the U.S. Centers for Disease Control and Prevention released new evidence supporting this advice. [1]
Researchers analyzed coronavirus infection rates, in Kansas, following a statewide mask mandate.

They found that counties that chose to enforce the mandate saw their cases decrease (even though rates were initially considerably higher in the 24 counties that required masks). Counties that chose to opt out saw their cases continue to rise.

On average, the counties that required masks saw a 6% reduction in cases (calculated as a seven-day rolling average of new daily cases per capita). In contrast, the counties that opted out saw a 100% increase.
As the study notes, the findings were consistent with declines in coronavirus cases observed in 15 states and the District of Columbia, where masks were mandated, compared with states that didn't require the face coverings.

[1] “Trends in County-Level COVID-19 Incidence in Counties With and Without a Mask Mandate — Kansas, June 1 – August 23, 2020"
~ CDC Morbidity and Mortality Weekly Report

“Wearing masks is a CDC-recommended* approach to reduce the spread of SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19), by reducing the spread of respiratory droplets into the air when a person coughs, sneezes, or talks and by reducing the inhalation of these droplets by the wearer...
... he decrease in cases among mandated counties and the continued increase in cases in nonmandated counties adds to the evidence supporting the importance of wearing masks and implementing policies requiring their use to mitigate the spread of SARS-CoV-2
..."

CDC M&M Report https://www.cdc.gov/mmwr/volumes/69/...mm6947e2-H.pdf
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Old 24-11-2020, 06:46   #161
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Re: Science & Technology News

Why preventing hot spots of transmission is key to stopping/slowing the COVID-19 pandemic.
In COVID-19, and many infectious diseases, most (infected) people don't actually infect anyone else.
A small percentage of people (superspreaders) cause most of the transmission.

Around 10% of people seem to be responsible for the vast majority of COVID spread [1].
A study from India concluded that 8% of infected people caused 60% of the secondary cases; 70% of people did not pass the virus on to anyone else.[2]
In late February, drug company Biogen held its annual conference in Boston. The United States had fewer than 20 known COVID-19 cases at the time. A study estimates it led to tens of thousands of cases in the Boston area alone. [3]

If a small minority of cases leads to most of the spread, then stopping these people from transmitting, should bring the pandemic under (partial) control.

One key strategy is to eliminate the conditions that favor superspreading.
Researchers have identified several factors that make superspreading events more likely, known as the three Cs:
closed spaces with poor ventilation,
crowds,
and
close contact settings.

Shouting, singing, and heavy breathing also seem to increase the risk of superspreading.


[1] “Estimating the overdispersion in COVID-19 transmission using outbreak sizes outside China” ~ by Akira Endo et al
80% of secondary transmissions may have been caused by a small fraction of infectious individuals (~10%).
https://wellcomeopenresearch.org/articles/5-67

[2] “Epidemiology and transmission dynamics of COVID-19 in two Indian states” ~ by Ramanan Laxminarayan et al
Superspreading predominated, with 5% of infected individuals accounting for 80% of cases. Enhanced transmission risk was apparent among children and young adults, who accounted for one-third of cases.
https://science.sciencemag.org/content/370/6517/691

[3] “Phylogenetic[*] analysis of SARS-CoV-2 in the Boston area highlights the role of recurrent importation and superspreading events” ~ by Jacob Lemieux et al
https://www.medrxiv.org/content/10.1....23.20178236v1

* Phylogenetics is the study of evolutionary relationships, among biological entities/organisms.
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Old 24-11-2020, 07:06   #162
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Re: Science & Technology News

MMR2 vaccine could protect against COVID-19 or, at least, ameliorate some symptoms.


https://medicalxpress.com/news/2020-...ne-covid-.html
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Old 24-11-2020, 07:27   #163
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Re: Science & Technology News

Quote:
Originally Posted by Ded reckoner View Post
MMR2 vaccine could protect against COVID-19 or, at least, ameliorate some symptoms.
https://medicalxpress.com/news/2020-...ne-covid-.html
Good article.

The study referenced above:
“Analysis of Measles-Mumps-Rubella (MMR) Titers of Recovered COVID-19 Patients” ~ by Jeffrey E. Gold et al

”... The significance of our study is that it showed that mumps titers related to the MMR II vaccine are significantly and inversely correlated with the severity of COVID-19-related symptoms, supporting the theorized association between the MMR vaccine and COVID-19 severity...’

Here ➥ https://mbio.asm.org/content/11/6/e02628-20
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Old 25-11-2020, 11:14   #164
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Re: Science & Technology News

Lucky mistake for AstraZeneca vaccine
AstraZeneca says that the striking improvement in efficacy of its COVID-19 vaccine, developed with the University of Oxford, UK, was discovered because of a mistake. Milder-than-expected side-effects led to the discovery that some trial participants were inadvertently given a lower first dose. Early data show that the vaccine is 90% effective in protecting those people against COVID, compared with 62% in people who got two full doses. A top priority for researchers is finding out why. “The reason we had the half dose is serendipity,” said AstraZeneca executive Mene Pangalos.
https://www.theguardian.com/uk-news/...o-dosing-error

“Why Oxford’s positive COVID vaccine results are puzzling scientists”

Preliminary data suggest that the immunization was more effective in trial participants who received a lower dose.
https://www.nature.com/articles/d41586-020-03326-w
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Old 26-11-2020, 06:14   #165
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Re: Science & Technology News

“COVID Models Show How to Avoid Future Lockdowns” ~ by Stacey McKenna
"The models could help inform policy on everything from mask mandates to social distancing ...
... Scientists have already begun incorporating various degrees of social distancing and mask use into their predictions of the pandemic’s course. The models have gotten more sophisticated and responsive during the course of the pandemic. They all show with high degrees of certainty that masking and distancing save lives. And increasingly, they put a number on how these behaviors determine how many people will live or die...”

https://www.scientificamerican.com/a...ure-lockdowns/

“The temporal association of introducing and lifting non-pharmaceutical interventions with the time-varying reproduction number (R) of SARS-CoV-2: a modelling study across 131 countries”~ by You Li, et al ➥ https://www.thelancet.com/journals/l...785-4/fulltext

“Wrong but Useful — What Covid-19 Epidemiologic Models Can and Cannot Tell Us”
~ by Inga Holmdahl and Caroline Buckee ➥ https://www.nejm.org/doi/full/10.1056/NEJMp2016822
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