Tag Archives: SARS-CoV-2
Summer Sunlight Could Inactivate 90% of Coronavirus Particles in 30 minutes
A team of scientists is calling for greater research into how sunlight inactivates SARS-CoV-2 after realizing there’s a glaring discrepancy between the most recent theory and experimental results. UC Santa Barbara mechanical engineer Paolo Luzzatto-Fegiz and colleagues noticed the virus was inactivated as much as eight times faster in experiments than the most recent theoretical model predicted.
“The theory assumes that inactivation works by having UVB hit the RNA of the virus, damaging it,” explained Luzzatto-Fegiz.
But the discrepancy suggests there’s something more going on than that, and figuring out what this is may be helpful for managing the virus.
UV light, or the ultraviolet part of the spectrum, is easily absorbed by certain nucleic acid bases in DNA and RNA, which can cause them to bond in ways that are hard to fix.
But not all UV light is the same. Longer UV waves, called UVA, don’t have quite enough energy to cause problems. It’s the mid-range UVB waves in sunlight that are primarily responsible for killing microbes and putting our own cells at risk of Sun damage.
Short-wave UVC radiation has been shown to be effective against viruses such as SARS-CoV-2, even while it’s still safely enveloped in human fluids.
But this type of UV doesn’t usually come into contact with Earth’s surface, thanks to the ozone layer.
“UVC is great for hospitals,” said co-author and Oregon State University toxicologist Julie McMurry. “But in other environments – for instance, kitchens or subways – UVC would interact with the particulates to produce harmful ozone.”
In July 2020, an experimental study tested the effects of UV light on SARS-CoV-2 in simulated saliva. They recorded the virus was inactivated when exposed to simulated sunlight for between 10-20 minutes.
“Natural sunlight may be effective as a disinfectant for contaminated nonporous materials,” Wood and colleagues concluded in the paper.
Luzzatto-Feigiz and team compared those results with a theory about how sunlight achieved this, which was published just a month later, and saw the math didn’t add up. his study found the SARS-CoV-2 virus was three times more sensitive to the UV in sunlight than influenza A, with 90 percent of the coronavirus‘s particles being inactivated after just half an hour of exposure to midday sunlight in summer.
By comparison, in winter light infectious particles could remain intact for days.
Source: https://www.news.ucsb.edu/
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https://www.sciencealert.com/
New Nanoparticle-delivered COVID-19 Vaccine
Researchers from Cleveland Clinic’s Global Center for Pathogen Research & Human Health have developed a promising new COVID-19 vaccine candidate that utilizes nanotechnology and has shown strong efficacy in preclinical disease models.
According to new findings published in mBio, the vaccine produced potent neutralizing antibodies among preclinical models and also prevented infection and disease symptoms in the face of exposure to SARS-CoV-2 (the virus that causes COVID-19). An additional reason for the vaccine candidate’s early appeal is that it may be thermostable, which would make it easier to transport and store than currently authorized COVID-19 vaccines.
“Our vaccine candidate delivers antigens to trigger an immune response via nanoparticles engineered from ferritin–a protein found in almost all living organisms,” said Jae Jung, PhD, director of the Global Center for Human Health & Pathogen Research and co-senior author on the study. “This protein is an attractive biomaterial for vaccine and drug delivery for many reasons, including that it does not require strict temperature control.”
Added Dokyun (Leo) Kim, a graduate student in Dr. Jung’s lab and co-first author on the study, “This would dramatically ease shipping and storage constraints, which are challenges we’re currently experiencing in national distribution efforts. It would also be beneficial for distribution to developing countries.”
Other benefits of the protein nanoparticles include minimizing cellular damage and providing stronger immunity at lower doses than traditional protein subunit vaccines against other viruses, like influenza.
The team’s vaccine uses the ferritin nanoparticles to deliver tiny, weakened fragments from the region of the SARS-CoV-2 spike protein that selectively binds to the human entry point for the virus (this fragment is called the receptor-binding domain, or RBD). When the SARS-CoV-2 RBD binds with the human protein called ACE2 (angiotensin-converting enzyme 2), the virus can enter host cells and begin to replicate.
The researchers tested their vaccine candidate on a ferret model of COVID-19, which reflects the human immune response and disease development better than other preclinical models. Dr. Jung, a foremost authority in virology and virus-induced cancers, previously developed the world’s first COVID-19 ferret model–a discovery that has significantly advanced research into SARS-CoV-2 infection and transmission.
Source: https://www.lerner.ccf.org/
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https://www.eurekalert.org/
Janssen Vaccine could be Rolled Out in Europe by March 15
The European Medicines Agency (EMA) has received an application for conditional marketing authorisation (CMA) for a COVID-19 vaccine developed by Janssen-Cilag International N.V. Janssen is a subsidiary of the giant pharma-company Johnson & Johnson.
EMA’s human medicines committee (CHMP) will assess the vaccine, known as COVID-19 Vaccine Janssen, under an accelerated timetable. The Committee could issue an opinion by the middle of March 2021, provided the company’s data on the vaccine’s efficacy, safety and quality are sufficiently comprehensive and robust.
Such a short time for evaluation is only possible because EMA has already reviewed some data during a rolling review. During this phase, EMA assessed quality data and data from laboratory studies which looked at how well the vaccine triggers the production of antibodies and immune cells that target SARS-CoV-2 (the virus that causes COVID-19). The Agency also looked at clinical safety data on the viral vector used in the vaccine.
EMA is now assessing additional data on the efficacy and safety of the vaccine as well as its quality. If EMA concludes that the benefits of the vaccine outweigh its risks, it will recommend granting a CMA. The European Commission will then issue a decision on whether to grant a CMA valid in all EU and EEA Member States within days.
This is the fourth CMA application for a COVID-19 vaccine since the start of the current pandemic. It comes after EMA’s evaluation of vaccines from BioNTech/Pfizer, Moderna and AstraZeneca. These vaccines are now authorised in the EU and are among the tools Member States are using to combat COVID-19.
Source: https://www.ema.europa.eu/
The Vaccination against Covid-19 Prevents the Transmission of the Virus
A growing body of evidence suggests that the Covid-19 vaccine can slow the spread of the coronavirus, Dr. Anthony Fauci said Wednesday. Whether vaccination can prevent transmission of the virus is “the looming question,” Fauci, director of the National Institute of Allergy and Infectious Diseases, said during a White House coronavirus response team briefing.
“If a person gets infected despite being vaccinated — we refer to that as a ‘breakthrough’ infection — does that person have the capability of transmitting to another person?” “There have been some studies that are pointing in a very favorable direction,” he said, adding that these studies will have to be corroborated by additional research.
Fauci highlighted two recent studies that looked at a person’s viral load — that is, how much virus he or she has in the body — and transmissibility. One study from Spain, published Feb. 2 in The Lancet, found a direct correlation between viral load and transmissibility. The higher the viral load, the greater the transmissibility of the virus.
That’s in line with what years of research on HIV have shown: there’s a direct link between the viral load in someone’s blood and the likelihood that individual will transmit HIV to a sexual partner, Fauci said.
For SARS-CoV-2, the virus that causes Covid-19, researchers are focused on how much virus is found the nasopharynx, the upper part of the throat behind the nose that’s reached with a long, skinny swab.
How Does an mRNA Vaccine Work?
The COVID-19 pandemic has brought unusual attention to everything from handwashing to polymerase chain reaction (PCR) tests. As we move into the later stages of this pandemic, though, a different scientific concept has dominated the national conversation: vaccines. The study of the human immune system and how vaccines influence it is complex and sometimes counterintuitive, and the deployment of a new method for immunization based on mRNA has made it all the more confusing.
The two vaccines that have received Emergency Use Authorizations (EUAs) from the Food and Drug Administration are both mRNA vaccines. And since they’re our only hope for ending this pandemic, it’s crucial to understand how they work—and why you should get one.
Vaccines come in a few main forms, but they share the same central goal: equip our immune systems with the tools to handily defeat a pathogen we might encounter in the future. Think of it like a practice round before your body sees the real thing.
The exact way our bodies develop this preemptive immunity depends on the kind of vaccine we’re given. Live-attenuated vaccines provide our cells with a weakened version of a pathogen; protein subunit vaccines give just one part of a bad guy, so immune cells know how to recognize that part of a virus or bacterium. But mRNA (short for messenger RNA) vaccines actually provide our cells with the instructions for making a protein from the pathogen, in essence creating their own practice dummy. Our own cells produce the viral protein specific to, say, SARS-CoV-2, and then our immune system learns to recognize the proteins.
Source: https://www.popsci.com/
Single Dose Nanoparticle Vaccine Efficient To Produce Covid Antibodies
Across the world, health care workers and high-risk groups are beginning to receive COVID-19 vaccines, offering hope for a return to normalcy amidst the pandemic. However, the vaccines authorized for emergency use in the U.S. require two doses to be effective, which can create problems with logistics and compliance. Now, researchers reporting in ACS Central Science have developed a nanoparticle vaccine that elicits a virus-neutralizing antibody response in mice after only a single dose.
The primary target for COVID-19 vaccines is the spike protein, which is necessary for SARS-CoV-2’s entry into cells. Both of the vaccines currently authorized in the U.S. are mRNA vaccines that cause human cells to temporarily produce the spike protein, triggering an immune response and antibody production.
Peter Kim and colleagues wanted to try a different approach: a vaccine consisting of multiple copies of the spike protein displayed on ferritin nanoparticles. Ferritin is an iron storage protein found in many organisms that self-assembles into a larger nanoparticle. Other proteins, such as viral antigens, can be fused to ferritin so that each nanoparticle displays several copies of the protein, which might cause a stronger immune response than a single copy.
The researchers spliced spike protein and ferritin DNA together and then expressed the hybrid protein in cultured mammalian cells. The ferritin self-assembled into nanoparticles, each bearing eight copies of the spike protein trimer. The team purified the spike/ferritin particles and injected them into mice. After a single immunization, mice produced neutralizing antibody titers that were at least two times higher than those in convalescent plasma from COVID-19 patients, and significantly higher than those in mice immunized with the spike protein alone. A second immunization 21 days later produced even higher antibody levels. Although these results must be confirmed in human clinical trials, they suggest that the spike/ferritin nanoparticles may be a viable strategy for single-dose vaccination against COVID-19, the researchers say.
Source: https://www.acs.org/
First Antibody Treatment For COVID-19
Scientists in the UK have just recruited the first participants in the world to be part of a new long-acting antibody study. If the treatment is effective, it could give those who have already been exposed to SARS-CoV-2 protection from developing COVID-19.
“We know that this antibody combination can neutralise the virus,” explains University College London Hospitals (UCLH) virologist Catherine Houlihan. “So we hope to find that giving this treatment via injection can lead to immediate protection against the development of COVID-19 in people who have been exposed – when it would be too late to offer a vaccine.”
This might not be the first antibody treatment for COVID-19 you’ve heard of. Outgoing US President Donald Trump was given monoclonal antibodies when he came down with the disease, and in the US two different antibody treatments – casirivimab and imdevimab – received emergency approval back in November. But those antibody treatments are given to patients with mild or moderate COVID-19, who risk progressing to a severe version of the disease.
“In a clinical trial of patients with COVID-19, casirivimab and imdevimab, administered together, were shown to reduce COVID-19-related hospitalisation or emergency room visits in patients at high risk for disease progression within 28 days after treatment when compared to placebo,” the FDA explained in a press statement when the drugs were approved. This new antibody therapy, called AZD7442 and developed by UCLH and AstraZeneca, is a little different. AZD7442 is a combination of two monoclonal antibodies AZD8895 and AZD1061, which both target the receptor binding domain of the SARS-CoV-2 spike protein.
“By targeting this region of the virus’s spike protein, antibodies can block the virus’s attachment to human cells, and, therefore, is expected to block infection,” the team wrote on the US ClinicalTrials.gov website. “Amino acid substitutions have been introduced into the antibodies to both extend their half-lives, which should prolong their potential prophylactic benefit, and decrease Fc effector functionin order to decrease the potential risk of antibody-dependent enhancement of disease.”
Antibodies are little Y-shaped proteins that lock on to a particular section – called an antigen – of a virus, bacterium or other pathogen, and either ‘tag‘ it to be attacked by the immune system, or directly block the pathogen from invading our cells. Normal antibodies are produced by your body after an infection, while monoclonal antibodies are cloned in a lab and can be injected into a person already infected, to give the immune system a hand in the fight.
The researchers are hoping that AZD7442 – which is just starting the Storm Chaser study (the name for its phase 3 trial) – provides protection for those that have been exposed to the virus but do not yet have symptoms. Effectively, they’re trying to stop COVID-19 happening in the first place. “If you are dealing with outbreaks in settings such as care homes, or if you have got patients who are particularly at risk of getting severe COVID, such as the elderly, then this could well save a lot of lives,” said University of East Anglia infectious disease expert Paul Hunter.
Source: https://www.sciencealert.com/
Paper-based Sensor Detects COVID-19 in Five minutes
As the COVID-19 pandemic continues to spread across the world, testing remains a key strategy for tracking and containing the virus. Bioengineering graduate student, Maha Alafeef, has co-developed a rapid, ultrasensitive test using a paper-based electrochemical sensor that can detect the presence of the virus in less than five minutes. The team led by professor Dipanjan Pan reported their findings in ACS Nano.
“Currently, we are experiencing a once-in-a-century life-changing event,” said Alafeef. “We are responding to this global need from a holistic approach by developing multidisciplinary tools for early detection and diagnosis and treatment for SARS-CoV-2.”
There are two broad categories of COVID-19 tests on the market. The first category uses reverse transcriptase real-time polymerase chain reaction (RT-PCR) and nucleic acid hybridization strategies to identify viral RNA. Current FDA-approved diagnostic tests use this technique. Some drawbacks include the amount of time it takes to complete the test, the need for specialized personnel and the availability of equipment and reagents. The second category of tests focuses on the detection of antibodies. However, there could be a delay of a few days to a few weeks after a person has been exposed to the virus for them to produce detectable antibodies.
n recent years, researchers have had some success with creating point-of-care biosensors using 2D nanomaterials such as graphene to detect diseases. The main advantages of graphene-based biosensors are their sensitivity, low cost of production and rapid detection turnaround. “The discovery of graphene opened up a new era of sensor development due to its properties. Graphene exhibits unique mechanical and electrochemical properties that make it ideal for the development of sensitive electrochemical sensors,” said Alafeef. The team created a graphene-based electrochemical biosensor with an electrical read-out setup to selectively detect the presence of SARS-CoV-2 genetic material.
There are two components to this biosensor: a platform to measure an electrical read-out and probes to detect the presence of viral RNA. To create the platform, researchers first coated filter paper with a layer of graphene nanoplatelets to create a conductive film. Then, they placed a gold electrode with a predefined design on top of the graphene as a contact pad for electrical readout. Both gold and graphene have high sensitivity and conductivity which makes this platform ultrasensitive to detect changes in electrical signals.
Source: https://pubs.acs.org
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https://bioengineering.illinois.edu/
Drug-free Nasal Spray Prevents SARS-CoV-2 Infection
Auris Medical Holding Ltd. (NASDAQ: EARS), a clinical-stage company dedicated to developing therapeutics that address important unmet medical needs in neurotology, rhinology and allergy and CNS disorders, today announced positive efficacy data from testing AM-301 in vitro. AM-301 is a drug-free nasal spray being developed by the Company’s affiliate Altamira Medica for protection against airborne pathogens and allergens.
AM-301 was tested for its capability to prevent or mitigate SARS-CoV-2 infection of nasal epithelial cells, which are part of the nasal mucosa and the first barrier against continuously inhaled substances such as pathogens and allergens. The experiment was performed over four days on reconstituted human nasal epithelia, which are frequently used to study the effects of human respiratory viruses. In saline-treated control cultures, Sars-CoV-2 replicated efficiently, resulting in a rapid increase in viral titer.
In contrast, daily treatment with AM-301, beginning right before inoculation, showed effective protection against viral infection. 48 hours post-infection, average virus titers were 90.0% lower than those observed in controls (p<0.05). 72 hours and 96 hours post-infection, average virus titers were 99.2 and 99.4% lower, respectively (p<0.001). Even when unbound virus was not removed daily through apical washing, allowing the virus to accumulate in the culture for 4 days, the reduction in viral titer was 92.4% compared to saline-treated controls (p<0.001).
Pfizer And Biontech Announce Vaccine Against COVID-19
Pfizer Inc. (NYSE: PFE) and BioNTech SE (Nasdaq: BNTX) today announced their mRNA-based vaccine candidate, BNT162b2, against SARS-CoV-2 has demonstrated evidence of efficacy against COVID-19 in participants without prior evidence of SARS-CoV-2 infection, based on the first interim efficacy analysis conducted on November 8, 2020 by an external, independent Data Monitoring Committee (DMC) from the Phase 3 clinical study.
After discussion with the Food and Drug Administration (FDA), the companies recently elected to drop the 32-case interim analysis and conduct the first interim analysis at a minimum of 62 cases. Upon the conclusion of those discussions, the evaluable case count reached 94 and the DMC performed its first analysis on all cases. The case split between vaccinated individuals and those who received the placebo indicates a vaccine efficacy rate above 90%, at 7 days after thed second dose. This means that protection is achieved 28 days after the initiation of the vaccination, which consists of a 2-dose schedule. As the study continues, the final vaccine efficacy percentage may vary. The DMC has not reported any serious safety concerns.
“Today is a great day for science and humanity. The first set of results from our Phase 3 COVID-19 vaccine trial provides the initial evidence of our vaccine’s ability to prevent COVID-19,” said Dr. Albert Bourla, Pfizer Chairman and CEO. “We are reaching this critical milestone in our vaccine development program at a time when the world needs it most with infection rates setting new records, hospitals nearing over-capacity and economies struggling to reopen. With today’s news, we are a significant step closer to providing people around the world with a much-needed breakthrough to help bring an end to this global health crisis. We look forward to sharing additional efficacy and safety data generated from thousands of participants in the coming weeks.”
Source: https://www.pfizer.com/
