Study of 11,000 infected adults during the Delta wave in Israel sees vaccine’s protection disappearing at six months and restored by third dose.

An Israeli study has found that the two-dose Pfizer/BioNTech vaccine against Covid-19 is initially effective in reducing the viral load of breakthrough infections — even with the Delta variant of the SARS-CoV-2 coronavirus.

The lower the viral load, the lower the chance of transmitting the virus and developing symptoms.

But after analyzing viral loads of over 11,000 infected adults during the summer Delta-dominant wave in Israel, the researchers saw the vaccine’s protection starts declining two months after the second dose and disappears by about six months.

“Encouragingly, we find that this diminishing vaccine effectiveness on breakthrough infection viral loads is restored following the booster vaccine,” the researchers write.

In fact, the third vaccination caused a more than four-fold reduction in viral loads.

The study results, posted September 1 on the medRxiv website prior to peer review, was carried out by a multidisciplinary team of researchers from the Technion-Israel Institute of Technology, Tel Aviv University and Maccabi Health Services.

The findings seem to support Israel’s unprecedented decision, in July, to begin offering booster shots to citizens at least five months past their second vaccine dose.

As of now, more than 3 million Israelis have gotten that third shot. A recent Israeli study in the New England Journal of Medicine confirms the effectiveness of the booster at preventing both infection and severe illness.

How long the booster’s protection remains effective is a question that can be answered only by further research.

The study was supported by a grant from the Israel Science Foundation as part of the KillCorona-Curbing Coronavirus Research Program.

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COVID Booster Shot Reduces Viral Load, Limits Transmission, Israeli Study Finds

The study, which has yet to be peer-reviewed, analyzed samples from 11,000 people infected with the COVID delta variant in Israel and found booster shots reduced viral loads by a factor of four

A booster shot of Pfizer’s coronavirus vaccine significantly reduces viral load in patients infected with the delta variant, and therefore reduces the chances of transmission, a new Israeli study has found.

The study was conducted jointly by the Technion – Israel Institute of Technology and KSM – the Maccabi Research and Innovation Center. It was published on the MedRxiv website, which is for papers that haven’t yet been published in a scientific journal.

The researchers concluded that about six months after someone receives the second dose of the vaccine, its effectiveness at reducing viral load dissipates. But a third dose slashes viral loads by a factor of four, thereby restoring the vaccine’s effectiveness to what it was shortly after the second dose was administered.

The researchers analyzed 11,000 PCR swab tests conducted by the Maccabi health maintenance organization on patients who had been infected with the delta variant. These patients were divided into three groups – people who were never vaccinated, people who were infected within six months of getting the second dose and people who were infected after getting the booster shot.

“What we discovered is that the vaccine’s effectiveness with respect to viral load gradually wanes over time, until after six months, [viral load] reaches a high level, similar to that of an unvaccinated person,” said Matan Levine-Tiefenbrun, a doctoral student at Tel Aviv University who is also affiliated with the Technion and was the lead researcher. “Nevertheless, we discovered that the booster shot brings the viral load back down by a factor of four, to what it was before.”

The PCR test enables researchers to assess the size of the viral load based on how many times sequences of the virus’ DNA needed to be replicated to produce a result. The greater the number of replications required, the lower the initial viral load was. Analyzing large numbers of such tests enables researchers to identify broad trends – in this case, the relationship between and how long it has been since the patient’s last vaccine dose.

Viral load is a significant factor in both the likelihood of developing symptomatic illness and the likelihood of transmission, since someone who is coughing and sneezing will spread the virus more than an asymptomatic patient would.

The study found that people infected less than two months after their second dose had lower viral loads than unvaccinated people. Consequently, they also had milder symptoms and were less infectious.

But after those first two months, the researchers said, immune protection gradually begins waning and viral loads rise. This process peaks after about six months.

Aside from Levine-Tiefenbrun, the other researchers were Prof. Roy Kishony and Dr. Idan Yellin, both of the Techion, and a group of researchers from KSM led by Dr. Tal Patalon.

In March, this same group published an article in the journal Nature Medicine showing that Pfizer’s coronavirus vaccine starts significantly reducing viral load as early as 12 days after the first dose. But that study involved the alpha variant, also known as the U.K. variant, rather than delta.

“We’re seeing that the vaccines are also effective in the fourth wave, against the delta variant,” Kishony said. “The effectiveness seems very similar to what it was against the British variant after receipt of the first two doses.”

However, he added, the results of the earlier study can’t be compared directly to the results of the new study, “because the British variant has been pushed aside and disappeared.”

The new study bolsters the data from another Israeli study, this one peer-reviewed, that was published last week in the New England Journal of Medicine, and which FDA experts made use of in discussing whether to recommend booster shots in the United States. That study found that the vaccine’s effectiveness in preventing transmission declines significantly after six months, but even then, vaccinated people are roughly 50 percent less likely to infect others than unvaccinated people.

After the booster, however, Pfizer’s vaccine is 95 percent effective in preventing transmission, that study said.

Researchers at the Technion have developed a highly stretchable electronic material and a wearable sensor capable of identifying precise bending and twisting motions.

Scientists at the Technion-Israel Institute of Technology have produced a highly stretchable electronic material and a wearable sensor capable of identifying precise bending and twisting motions.

Essentially, it is an electronic skin.

The development will be able to help identify ailments and disease, for example, the early onset of Parkinson’s, or help amputees adapt to prosthetics, the developers have said.

It recognizes the range of movements that human joints normally makes with the precision of up to half a degree. This breakthrough is the result of collaborative work, headed by Professor Hossam Haick from the Wolfson Faculty of Chemical Engineering.

It was recently published in Advanced Materials, a peer-reviewed journal. 

Professor Haick’s lab focuses on wearable devices. Wearable motion sensors can currently recognize bending movement, but not twisting. Sensors that recognize twisting are large and cumbersome.

Ph.D candidate Yehu David Horev and postdoctoral fellow Dr. Arnab Maity have found a way to overcome this problem. Horev found a way to form a composite material that is both usable as a sensor and is flexible, stretchable, breathable, biocompatible, and does not change its electrical properties when stretched.

Dr. Maity was able to solve the mathematics of analysing the received signal.

The novel sensor is breathable, durable and lightweight, allowing it to be worn by humans for long periods of time. 

“This sensor has many possible applications,” Prof. Haick stated. 

“It can be used in early disease diagnosis, alerting of breathing alterations, and motor system disorders such as Parkinson’s disease. It can be used to assist patients’ motor recovery and be integrated into prosthetic limbs. In robotics, the feedback it provides is crucial for precise motion. In industrial uses, such sensors are necessary in monitoring systems.”

TECHNION SCIENTISTS CREATED A WEARABLE MOTION SENSOR CAPABLE OF IDENTIFYING BENDING AND TWISTING

One doesn’t pay much attention to sensors, but they are omnipresent in modern life. A sensor is a device that responds to a physical stimulus such as heat, light, sound, pressure, magnetism or a particular motion and transmits a resulting impulse as for measurement or operating a control. It measures physical input from its environment and converts it into data that can be interpreted by either a human or a machine.

The most frequently used types of sensors are classified according to hat they react to – electric current or magnetic or radio sensors, humidity, fluid velocity or flow, pressure, temperature sensors, proximity sensors, optical sensors or position sensors.

Sensors are used in everyday objects such as touch-sensitive elevator buttons, lamps that brighten or dim by touching the base, along with innumerable applications of which most people are unaware. 

Aside from home use, sensor applications include manufacturing, medicine, machinery, planes and aerospace, vehicles, robotics and many other aspects of life. 

Wearable strain sensors have been attracting special attention in the detection of human posture and activity, as well as for the assessment of physical rehabilitation and kinematic, but it is a challenge to fabricate stretchable and comfortable-to-wear permeable strain sensors that can provide highly accurate and continuous motion recording while exerting minimal constraints and maintaining low interference with the body. 

Now, scientists at the Technion-Israel Institute of Technology in Haifa have created a wearable motion sensor capable of identifying bending and twisting. Made from a highly stretchable electronic material, it is essentially an electronic skin capable of recognizing the range of movement human joints normally make, with up to half a degree precision. 

This breakthrough is the result of collaborative work among researchers from different fields in the Laboratory for Nanomaterial-Based Devices, headed by Prof. Hossam Haick from the Wolfson Faculty of Chemical Engineering. It was recently published in Advanced Materials under the title “Stretchable and Highly Permeable Nanofibrous Sensors for Detecting Complex Human Body Motion”

and was featured on the journal’s cover.

The new sensor has many possible applications,” said Haick. “It can be used in early disease diagnosis, alerting of breathing alterations, and motor system disorders such as Parkinson’s disease. It can also assist patients in their motor recovery and be integrated into prosthetic limbs. In robotics, the feedback it provides is crucial for precise motion. In industrial uses, such sensors are necessary in monitoring systems, putting them at the core of the Fourth Industrial Revolution.”

This breakthrough is the result of collaborative work between researchers from different fields in the Laboratory for Nanomaterial-Based Devices, which Haick heads. 

At present, existing wearable motion sensors can recognize bending movement, but not twisting. Existing twisting sensors, on the other hand, are large and cumbersome and cannot be worn.. This problem was overcome by doctoral candidate Yehu David Horev and postdoctoral fellow Dr. Arnab Maity. 

Horev found a way to form a composite material that was both conductive – and thus, usable as a sensor – and flexible, stretchable, breathable and biocompatible, I also did not change its electrical properties when stretched. 

Maity then solved the mathematics of analyzing the received signal, creating an algorithm capable of mapping bending and twisting motion – the nature of the movement, its speed and its angle. The novel sensor is breathable, durable and lightweight, making it possible to be worn on the human body for prolonged periods.

“Electrically conductive polymers are usually quite brittle,” explained Yehu about the challenge the group had overcome. “To solve this, we created a composite material that is a little like fabric. The individual polymer ‘threads’ cannot withstand the strain on the material, but their movement relative to each other lets it stretch without breaking. It is not too different from what lends stretch to T-shirts. This allows the conductive polymer withstand extreme mechanical conditions without losing its electrical properties.”

What makes this achievement more important is that the materials the group used are very inexpensive, resulting in a cheap sensor. “If we make a device that is very expensive, only a small number of institutions in the Western world could afford to use it. We want the technological advances we achieve to benefit everyone, regardless of their geographic location and socioeconomic status,” said Haick. True to his word, among the laboratory’s other projects is a tuberculosis-diagnosing sticker patch, which is sorely needed in developing countries.

Haick is an expert in the field of nanotechnology and non-invasive disease diagnosis who earned his doctorate from the Technion in 2002. After graduation, he completed two postdoctoral fellowships – first at the Weizmann Institute of Science in Rehovot and then at California Institute of Technology. He returned to the Technion at the end of 2006 as an assistant professor, becoming a full professor in 2011. 

He has published more than 220 publications in top-level journals in the field of nanotechnology, advanced/applied materials/chemistry and medicine, and technologies he and his team developed have led to the production of more than 42 patents and patent applications – many of which have been licensed to six international companies.

An Arab-Israeli scientist and engineer, Haick is a pioneer known for inventing the Nano Artificial Nose for detection of disease from exhaled breath.  He was included in more than 80 top-rank listings worldwide, including the “MIT Technology Review” list of 35 leading young scientists in the world, the “50 Sharpest Israeli Minds” and  the world’s top-100 influential innovators in the Digital Technology by Nominet Trust in London. 

A team of scientists has found why elderly people are more susceptible to COVID-19 and are working to reverse the aging process of the body’s immune system

Scientists from the Technion-Israel Institute of Technology say they have found a way to rejuvenate the aging process of the body’s immune system.

Prof. Doron Melamed and doctoral student Reem Dowery sought to understand why the elderly population is more susceptible to severe cases of COVID-19 and why the vaccines seem to be less effective and wane faster among this population.

The results of their work were published this month in the peer-reviewed, online medical journal Blood.

The secret begins with B cells, also known as B lymphocytes. These are the cells that produce antibodies against any pathogen that enters the body. They play a key role in protecting people from viruses and diseases.

B cells are produced in bone marrow and then travel through the blood to lymph nodes and the spleen, where they wait for pathogens to enter and then attack them.

“When you are young, you have young cells, and young cells have a very diverse ability to recognize anything [pathogenic] that comes into your body,” Melamed told The Jerusalem Post.

B cells do not live long, but they are constantly being replenished by new ones sent from the bone marrow, creating what Melamed calls “homeostasis,” a state in which the total number of B cells in the bone marrow and outside remains constant.

However, B cells do not just disappear. They turn into “memory” B cells so that if the body is exposed to a previous pathogen, the individual will not get sick. That is because the immune response will be fast and robust, and it will eliminate the pathogen, often without the individual knowing he or she had been exposed to it.

Unlike B cells, memory cells are long-lived.

“Imagine you are growing into adulthood, and you become an adult and then an older person,” Melamed said. “You accumulate in your body many memory cells. You are exposed all the time to pathogens, and hence you make more and more memory cells. Because these are so long-lived, there is no room left for new B cells.

”What happens when a new pathogen, such as the coronavirus, comes along? There are no young B cells that can recognize it.

That is one of the reasons why older people are more susceptible to severe COVID-19 and many other diseases.

As noted, this happens because of the body’s need for homeostasis, something that Melamed’s lab discovered a decade ago.

BUT THIS year, they took the discovery another step and figured out a mechanism to override the system.

“We found specific hormonal signals produced by the old B cells, the memory cells, that inhibit the bone marrow from producing new B cells,” Melamed said. “This is a huge discovery. It is like finding a needle in a haystack.

”It also means that, over time, specific drugs or treatments can be found to inhibit one of the hormones in the signaling pathway and get the bone marrow to produce new B cells.

What happens when a new pathogen, such as the coronavirus, comes along? There are no young B cells that can recognize it

.That is one of the reasons why older people are more susceptible to severe COVID-19 and many other diseases.

As noted, this happens because of the body’s need for homeostasis, something that Melamed’s lab discovered a decade ago.

BUT THIS year, they took the discovery another step and figured out a mechanism to override the system.
“We found specific hormonal signals produced by the old B cells, the memory cells, that inhibit the bone marrow from producing new B cells,” Melamed said. “This is a huge discovery. It is like finding a needle in a haystack.

”It also means that, over time, specific drugs or treatments can be found to inhibit one of the hormones in the signaling pathway and get the bone marrow to produce new B cells.

To validate their theory, Melamed’s lab collaborated with the departments of hematology and rheumatology at Sourasky Medical Center in Tel Aviv and Rambam Health Care Campus in Haifa. As part of treatment for some medical conditions, such as lupus, lymphoma and multiple sclerosis, patients undergo B cell depletion, meaning a significant amount of memory B cells is removed from their bodies.

Examining older patients who underwent this procedure, the group found that their immune systems rejuvenated, and their bodies could produce new B cells again.

An effect similar to B cell depletion can be produced by inhibiting one of the hormones in the signaling pathway that suppresses the production of new B cells.

“Now we understand that there is some kind of conversation between compartments in the body, between how B cells are produced and what controls that,” Melamed said.

In the interim, he recommended that doctors use this knowledge to protect the elderly better, such as by instituting a vaccination program targeted just for the adult population that preempts variants with an additional shot.

“Even every three or four months, vaccinate them again and again to ensure they maintain high antibodies,” Melamed said.

He also suggested mixing vaccines, such as combining a shot of a Pfizer mRNA vaccine with an AstraZeneca booster given several months later, “which may generate better stimulation of the elderly immune system.

”At the same time, clinical trials would be needed to determine how to safely inhibit the hormones to find a longer-term solution, hopefully before the next pandemic, Melamed said.