Wednesday, August 25, 2021
Rehab progress
My rehab after my recent health problems is going well. I now have more energy to blog. In the last few days I have been putting something up on most of my blogs most days. I have also revived my selective blog http://awesternheart.blogspot.com
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Rising number of breakthrough Delta infections among fully vaccinated
Chicago: A quarter of Los Angeles residents who caught COVID from May to July this year as the Delta variant surged were fully vaccinated.
The data, published in the US Centres for Disease Control and Prevention’s weekly report on death and disease, shows an increase in “breakthrough” infections among those who had both doses of a coronavirus vaccine.
The centre is relying on data from cohorts, such as the Los Angeles County study, to determine whether Americans need a third dose of COVID-19 vaccines to increase protection. Government scientists last week laid out a strategy for booster doses beginning on September 20, pending reviews from the US Food and Drug Administration and the CDC.
While a quarter of the COVID infections in the Los Angeles study were in the fully vaccinated, fewer than one in 20 was hospitalised.
While a quarter of the COVID infections in the Los Angeles study were in the fully vaccinated, fewer than one in 20 was hospitalised. CREDIT:AP
The new data released on Tuesday involved more than 43,000 reported infections among Los Angeles County residents aged 16 and older. Of them, 10,895, or 25.3 per cent occurred in fully vaccinated persons, and 1431, or 3.3 per cent, were in partially vaccinated persons. The majority of infections, however, were among the unvaccinated: 30,801 cases, or 71.4 per cent of the cohort.
The vaccines did, however, protect individuals from more severe symptoms. According to the study, only 3.2 percent of fully vaccinated individuals who tested positive for coronavirus were hospitalised, just 0.05 per cent were admitted to an intensive care unit and 0.25 per cent were placed on a ventilator.
Among the unvaccinated who caught COVID, 7.5 per cent were hospitalised, 1.5 per cent were admitted to an intensive care unit and 0.5 per cent required breathing support with a mechanical ventilator.
In addition to the LA County data, the CDC on Tuesday released an update on a study of healthcare workers that showed a significant drop in vaccine effectiveness among vaccinated frontline workers in eight states who became infected with the coronavirus.
The effectiveness of COVID-19 vaccines among healthcare workers declined to 66 per cent after the Delta variant became dominant, compared with 91 per cent before it arose, according to the report.
The vaccines are still protective, the centre said, and the finding must be interpreted with caution, as vaccine effectiveness might wane over time and the estimates of efficacy were imprecise.
“Although these interim findings suggest a moderate reduction in the effectiveness of Covid-19 vaccines in preventing infection, the sustained two-thirds reduction in infection risk underscores the continued importance and benefits of Covid-19 vaccination,” researchers wrote in the agency’s Morbidity and Mortality Weekly Report.
The findings echo earlier evidence from Israel and the UK suggesting COVID-19 vaccines lost some potency in preventing infections over time as the Delta variant spread.
The observational study tracked more than 4,000 health-care workers, first responders, and other front-line personnel in eight locations across six states from December 2020 to August 2021. They were tested weekly for COVID-19 infection, and about 83 per cent were vaccinated.
About two-thirds of those vaccinated had received the Pfizer shot, 2 per cent received Johnson & Johnson’s, and the rest received the Moderna vaccine.
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Q & A on Delta
The rise of Delta, which is far more easily transmitted from person to person than previous strains of the virus, has made going out in public riskier. That’s one reason why the Centers for Disease Control and Prevention (CDC) recently changed its masking recommendations—it now advises vaccinated people in areas with high levels of virus to wear a mask indoors. Figuring out when to take risks and when not to is largely a matter of individual circumstance and preference. For instance, people with weakened immune systems should be more cautious than those with robust immune systems. Here are answers to some other common questions:
Q: How great is the risk of getting sick if you’ve gotten the vaccine?
It depends on the vaccine. A study published in the New England Journal of Medicine in July showed that the twoshot Pfizer mRNA vaccine was 88 percent effective in preventing illness due to the Delta variant, down from 93.7 percent for the Alpha variant. The Moderna mRNA shot is thought to offer similar protection. The study found that the Astra-Zeneca vaccine was 67 percent effective against Delta, as opposed to 74.5 for Alpha.
Q: If vaccinated people can still be infected, should they worry about being able to transmit the virus to others?
Yes, but not as much as unvaccinated people should. According to internal CDC documents recently obtained by The Washington Post, vaccinated people who have been infected with the Delta variant may spread the virus as efficiently as unvaccinated people who are infected. Delta tends to concentrate in the nose and throat, which is why the C.D.C. wants everyone to mask up. However, because vaccinated people tend to have stronger immune responses to the virus, they are probably contagious for only a short time—though this scenario has not been studied rigorously.
Q: Can vaccinated people who show symptoms develop long-haul COVID-19?
Little is known about longhaul COVID. In a recent study of health care workers, 19 percent of vaccinated people who got sick still had symptoms after six weeks. Keep in mind that this is only one study with relatively few participants, so firm conclusions will have to wait for more data.
Q: When will children under the age of 12 be eligible for a shot?
Current estimates range from as little as a month or two to well into 2022. On the far side of the range: FDA officials say they expect children under 12 to be eligible for vaccination by midwinter, after another four to six months of clinical trials. Pfizer, though, is more optimistic. In June, it began a study of 4,500 kids aged 5-to-11 in the U.S., Poland, Finland and Spain and hopes to have enough data collected by September to ask officials for an emergency use authorization.
Q: How do doctors determine which variant you have?
COVID-19 tests don’t identify variants. To find out how prevalent a variant is, the CDC takes samples, identifies them by sequencing their genetic material and then estimates what proportion of infections a given variant accounts for.
Q: Are the symptoms different between the variants?
Symptoms from many variants are similar to those of the original virus—fever, dry cough, shortness of breath. However, Delta can also manifest more like a bad cold, with a runny nose, sore throat and headache. Recently, reports of loss of smell and taste have become less common, according to the Zoe Covid Symptom study.
Q: When does the immunity from the vaccine start to wane? Is it the same for mRNA vaccines and others?
Pfizer recently said that the effectiveness of its mRNA vaccine declines to 84 percent about four to six months after the second shot, based on an internal study that has not yet been peer reviewed. A study in the journal Nature suggested that the mRNA vaccines have potentially long-lasting immunity.
Q: Will everyone eventually need booster shots? Or only those who are elderly and/or immunocompromised?
It depends in part on what kind of variants arise in the future. For now, experts do not foresee a need for most healthy vaccinated people to get booster shots, but that could change. Public health officials have suggested that those with weakened immune systems may need to get boosters this winter.
Q: Is it safe to go back into an office to work?
Safe is a relative term. It depends on an individual’s health, circumstances and tolerance for risk. In an office where everybody is vaccinated and virus levels in the community are low, the risk is small. In an office where many people are unvaccinated and virus levels are high, the risk can be many times higher. The risk for an unvaccinated person is always higher than for a vaccinated person. Vaccinated people who are immunocompromised or are caring for someone who is vulnerable at home may want to keep their potential exposure to the virus as low as possible—which means avoiding crowded, poorly ventilated rooms and wearing masks when indoors with others who may not be vaccinated. Because the Delta variant is so highly transmissible, the CDC now recommends mask wearing for everyone in indoor settings in regions where virus levels are high.
Q: In light of the Delta variant, should we be rethinking resuming regular activities like going to restaurants, sporting events, concerts, flying on planes, etc.?
Most vaccines still offer excellent protection. However, the risk goes up with exposure to the virus—and the Delta variant, with its high transmissibility, has ratcheted up the risk for all activities. Risk tolerance varies from one person to the next, but in general it’s a good idea to be aware of situations that are likely to bring you into contact with high levels of virus. Crowded, stuffy bars are riskier than spacious, well ventilated restaurants. Airplanes usually have good ventilation, but you have to worry about that unmasked, unvaccinated person sitting next to you. If in doubt, wear a mask.
Q: If you’ve already had COVID-19 with mild symptoms, what are the benefits of getting the vaccine?
One big benefit of vaccination is that it reduces the overall level of virus in a population, which makes everyone safer. Some studies also suggest that vaccines provide better protection for longer than natural infection. For instance, a study in China, recently published in The Lancet, showed that only 40 percent of people who had gotten COVID-19 carried antibodies to the coronavirus months later.
Q: If you’ve already had COVID-19 and are getting the vaccine, do you need to get both shots?
Yes. A recent study in the U.K., published in Nature, found that a single shot of the Pfizer vaccine reduced illness from the Delta variant by 33 percent. Two weeks after the second shot, that protection rose to 88 percent.
https://blendle.com/i/newsweek/what-to-do-about-delta/bnl-newsweek-20210806-44_1
*****************************************IN BRIEF
Biden rejected U.S. intel predictions of rapid Afghan collapse (American Military News)
China sends bombers into Taiwan air defense zone (Washington Times)
Judge blocks Biden’s attempt to limit deportations (Washington Times)
15M votes in 2020 election unaccounted for (Daily Signal)
TX Dems return, quorum established for election integrity bill (Fox News)
FBI knew Ilhan Omar married her brother (Post Millennial)
CDC redefines “fully vaccinated” (Post Millennial)
GOP governors, school districts battle over mask mandates (Associated Press)
GA governor blocks COVID mandate on businesses (Just the News)
Home construction slumps on supply constraints (Epoch Times)
Firearms sales set new record (1945)
FTC refiles Facebook anti-trust lawsuit (CNBC)
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Also see my other blogs. Main ones below:
http://edwatch.blogspot.com (EDUCATION WATCH)
http://antigreen.blogspot.com (GREENIE WATCH)
http://pcwatch.blogspot.com (POLITICAL CORRECTNESS WATCH)
http://australian-politics.blogspot.com/ (AUSTRALIAN POLITICS
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Tuesday, August 24, 2021
Those Anti-Covid Plastic Barriers Probably Don’t Help and May Make Things Worse
Covid precautions have turned many parts of our world into a giant salad bar, with plastic barriers separating sales clerks from shoppers, dividing customers at nail salons and shielding students from their classmates.
Intuition tells us a plastic shield would be protective against germs. But scientists who study aerosols, air flow and ventilation say that much of the time, the barriers don’t help and probably give people a false sense of security. And sometimes the barriers can make things worse.
Research suggests that in some instances, a barrier protecting a clerk behind a checkout counter may redirect the germs to another worker or customer. Rows of clear plastic shields, like those you might find in a nail salon or classroom, can also impede normal air flow and ventilation.
Under normal conditions in stores, classrooms and offices, exhaled breath particles disperse, carried by air currents and, depending on the ventilation system, are replaced by fresh air roughly every 15 to 30 minutes. But erecting plastic barriers can change air flow in a room, disrupt normal ventilation and create “dead zones,” where viral aerosol particles can build up and become highly concentrated.
“If you have a forest of barriers in a classroom, it’s going to interfere with proper ventilation of that room,” said Linsey Marr, professor of civil and environmental engineering at Virginia Tech and one of the world’s leading experts on viral transmission. “Everybody’s aerosols are going to be trapped and stuck there and building up, and they will end up spreading beyond your own desk.”
There are some situations in which the clear shields might be protective, but it depends on a number of variables. The barriers can stop big droplets ejected during coughs and sneezes from splattering on others, which is why buffets and salad bars often are equipped with transparent sneeze guards above the food.
But Covid-19 spreads largely through unseen aerosol particles. While there isn’t much real-world research on the impact of transparent barriers and the risk of disease, scientists in the United States and Britain have begun to study the issue, and the findings are not reassuring.
A study published in June and led by researchers from Johns Hopkins, for example, showed that desk screens in classrooms were associated with an increased risk of coronavirus infection. In a Massachusetts school district, researchers found that plexiglass dividers with side walls in the main office were impeding air flow. A study looking at schools in Georgia found that desk barriers had little effect on the spread of the coronavirus compared with ventilation improvements and masking.
Before the pandemic, a study published in 2014 found that office cubicle dividers were among the factors that may have contributed to disease transmission during a tuberculosis outbreak in Australia.
British researchers have conducted modeling studies simulating what happens when a person on one side of a barrier — like a customer in a store — exhales particles while speaking or coughing under various ventilation conditions. The screen is more effective when the person coughs, because the larger particles have greater momentum and hit the barrier. But when a person speaks, the screen doesn’t trap the exhaled particles — which just float around it. While the store clerk may avoid an immediate and direct hit, the particles are still in the room, posing a risk to the clerk and others who may inhale the contaminated air.
“We have shown this effect of blocking larger particles, but also that the smaller aerosols travel over the screen and become mixed in the room air within about five minutes,” said Catherine Noakes, professor of environmental engineering for buildings at the University of Leeds in England. “This means if people are interacting for more than a few minutes, they would likely be exposed to the virus regardless of the screen.”
Dr. Noakes said erecting barriers may seem like a good idea but can have unintended consequences. She conducted a study published in 2013 that looked at the effect of partitions between beds in hospitals. The study showed that while some people were protected from germs, the partitions funneled the air in the room toward others.
So while a worker behind a transparent barrier might be spared some of the customer’s germs, a worker nearby or customers in line could still be exposed. Dr. Noakes said most screens she has seen are “poorly positioned and are unlikely to be of much benefit.”
“I think this may be a particular problem in places like classrooms where people are present for longer periods of time,” Dr. Noakes said. “Large numbers of individual screens impede the airflow and create pockets of higher and lower risk that are hard to identify.”
To understand why screens often have little effect on protecting people from aerosol particles, it helps to think about exhaled breath like a plume of cigarette smoke, Dr. Marr said.
“One way to think about plastic barriers is that they are good for blocking things like spitballs but ineffective for things like cigarette smoke,” Dr. Marr said. “The smoke simply drifts around them, so they will give the person on the other side a little more time before being exposed to the smoke. Meanwhile, people on the same side with the smoker will be exposed to more smoke, since the barriers trap it on that side until it has a chance to mix throughout the space.”
Most researchers say the screens most likely help in very specific situations. A bus driver, for instance, shielded from the public by a floor-to-ceiling barrier is probably protected from inhaling much of what passengers are exhaling. A bank cashier behind a wall of glass or a clerk checking in patients in a doctor’s office may be at least partly protected by a barrier.
A study by researchers with the National Institute for Occupational Safety and Health in Cincinnati tested different sized transparent barriers in an isolation room using a cough simulator. The study, which hasn’t yet been peer-reviewed, found that under the right conditions, taller shields, above “cough height,” stopped about 70 percent of the particles from reaching the particle counter on the other side, which is where the store or salon worker would be sitting or standing.
But the study’s authors noted the limitations of the research, particularly that the experiment was conducted under highly controlled conditions. The experiment took place in an isolation room with consistent ventilation rates that didn’t “accurately reflect all real-world situations,” the report said.
The study didn’t consider that workers and customers move around, that other people could be in the room breathing the redirected particles and that many stores and classrooms have several stations with acrylic barriers, not just one, that impede normal air flow.
While further research is needed to determine the effect of adding transparent shields around school or office desks, all the aerosol experts interviewed agreed that desk shields were unlikely to help and were likely to interfere with the normal ventilation of the room. Depending on the conditions, the plastic shields could cause viral particles to accumulate in the room.
“If there are aerosol particles in the classroom air, those shields around students won’t protect them,” said Richard Corsi, the incoming dean of engineering at the University of California, Davis. “Depending on the air flow conditions in the room, you can get a downdraft into those little spaces that you’re now confined in and cause particles to concentrate in your space.”
Aerosol scientists say schools and workplaces should focus on encouraging workers and eligible students to be vaccinated, improving ventilation, adding HEPA air filtering machines when needed and imposing mask requirements — all of which are proven ways to reduce virus transmission.
The problem, experts say, is that most people in charge of erecting barriers in offices, restaurants, nail salons and schools are not doing so with the assistance of engineering experts who can evaluate air flow and ventilation for each room.
People shouldn’t panic when they see transparent barriers, but they shouldn’t view them as fully protective, either. Workers and students who have transparent shields around them should continue to wear a mask to lower risk, Dr. Corsi said.
“Air flow in rooms is pretty complicated,” Dr. Corsi said. “Every room is different in terms of the arrangement of the furniture, the height of the walls and ceilings, the vents, where the book shelves are. All of these things have a huge impact on the actual flow and air distribution in a room because every classroom or office space is different.”
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Covid antibody treatment lowered risk of symptomatic disease by 77% in trial
A new coronavirus antibody treatment developed by drugs giant AstraZeneca and aimed at people who cannot be vaccinated reduced the risk of developing symptomatic disease by 77%, the company said.
The results of the Provent phase III pre-exposure prophylaxis trial showed there were no cases of severe Covid or Covid-related deaths in those treated with the “antibody cocktail” AZD7442, AstraZeneca said on Friday.
The study of more than 5,000 adults found AZD7442, a combination of two long-acting antibodies, also reduced the risk of developing symptomatic Covid-19 by 77% compared to a placebo.
In the placebo group there were three cases of severe coronavirus which included two deaths, the company added.
The drugs company said the antibody combination, which is delivered through an injection to the muscle, could give people up to 12 months of protection from Covid-19.
It is the first non-vaccine antibody combination modified to provide potentially long-lasting protection that has demonstrated prevention of Covid-19 in a clinical trial, AstraZeneca added.
Sir Mene Pangalos, executive vice-president of biopharmaceuticals R&D at AstraZeneca, said: “We need additional approaches for individuals who are not adequately protected by Covid-19 vaccines.
“We are very encouraged by these efficacy and safety data in high-risk people, showing our long-acting antibody combination has the potential to protect from symptomatic and severe disease, alongside vaccines.
“We look forward to sharing further data from the AZD7442 phase III clinical trial programme later this year.”
More than 75% of participants in the trial had co-morbidities and other characteristics that are associated with an increased risk of severe Covid-19 or cause a reduced immune response to vaccination, AstraZeneca said.
These include those with immunosuppressive disease or taking immunosuppressive medications, diabetes, severe obesity or cardiac disease, chronic obstructive pulmonary disease, chronic kidney and chronic liver disease.
The long-acting antibodies were well tolerated and preliminary analyses showed adverse events were balanced between the placebo and AZD7442 groups, AstraZeneca added.
AZD7442 could be an important tool in our arsenal to help people who may need more than a vaccine to return to their normal lives
Myron J Levin, principal investigator on the trial
The participants will continue to be monitored for 15 months, the company said.
AstraZeneca also said that preliminary “in vitro” findings from investigators at Oxford University and Columbia University show AZD7442 neutralises recent emergent Covid strains, including the Delta variant.
Myron J Levin, professor of paediatrics and medicine at the University of Colorado School of Medicine and principal investigator on the trial, said: “The Provent data show that one dose of AZD7442, delivered in a convenient intramuscular form, can quickly and effectively prevent symptomatic Covid-19.
“With these exciting results, AZD7442 could be an important tool in our arsenal to help people who may need more than a vaccine to return to their normal lives.”
AstraZeneca said it will prepare regulatory submissions of the data for health authorities for potential emergency use authorisation or conditional approval of AZD7442.
Professor Penny Ward, visiting professor in pharmaceutical medicine at King’s College London, said the new treatment could be a very important option for patients at high risk from Covid who have responded poorly to vaccination or who must take immune-suppressing treatment for other diseases.
It could potentially be game changing for these individuals, who are currently being advised to continue to shield despite being fully vaccinated
Professor Penny Ward, King’s College London
She added: “Indeed it could potentially be game changing for these individuals, who are currently being advised to continue to shield despite being fully vaccinated.
“Despite the success of vaccination some individuals do not respond as well and remain at higher risk of disease, hospitalisation and death. Prophylaxis with passive antibody therapy can help these folks further and reduce morbidity and mortality in this important population subset.
“They can be used to protect people while they undergo cancer treatment, for example.”
But Prof Ward said while the initial data was “encouraging” full publication of the results was need to understand the merits of the product and how to use it “most effectively” in practice.
Helen Rowntree, director for research, services and engagement for Blood Cancer UK, said the Medicines and Healthcare products Regulatory Agency (MHRA) needed to urgently assess the drug for approval for use in the UK.
If approved, the Government needs to draw up plans for giving it to people with blood cancer as quickly as possible, she added.
Ms Rowntree said: “This is great news for people with blood cancer because while their weakened immune systems mean they are less likely to respond to vaccines, this treatment does not rely on the immune system to produce antibodies to fight off the virus.
“This means that this may even be the game changer that potentially gives people with blood cancer the same kind of protection from Covid as the vaccines are already giving people who don’t have blood cancer.”
https://au.yahoo.com/news/covid-antibody-treatment-lowered-risk-112327164.html
*****************************************Also see my other blogs. Main ones below:
http://edwatch.blogspot.com (EDUCATION WATCH)
http://antigreen.blogspot.com (GREENIE WATCH)
http://pcwatch.blogspot.com (POLITICAL CORRECTNESS WATCH)
http://australian-politics.blogspot.com/ (AUSTRALIAN POLITICS
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