Monthly Archives: November 2020
The Moderna vaccine is 94.5% effective against coronavirus, according to early data released Monday by the company, making it the second vaccine in the United States to have a stunningly high success rate.”These are obviously very exciting results,” said Dr. Anthony Fauci, the nation’s top infectious disease doctor. “It’s just as good as it gets — 94.5% is truly outstanding.”
Vaccinations could begin in the second half of December, Fauci said. Vaccinations are expected to begin with high-risk groups and to be available for the rest of the population next spring.
Fauci says he expects the first Covid-19 vaccinations to begin “towards the latter part of December, rather than the early part of December.”
The blood-brain barrier is the main obstacle in treating neurodegenerative diseases such as Alzheimer and Parkinson. According to a recent study conducted by Jean-Michel Rabanel, a postdoctoral researcher under the supervision of Professor Charles Ramassamy, nanoparticles with specific properties could cross this barrier and be captured by neuronal cells. Researchers are confident that these results will open important prospects for releasing drugs directly to the brain. This breakthrough finding would enable improved treatment for neurodegenerative diseases affecting more than 565,000 Canadians, including 141,000 Quebecers.
“The blood-brain barrier filters out harmful substances to prevent them from freely reaching the brain. But this same barrier also blocks the passage of drugs,” explains the pharmacologist Charles Ramassamy. Typically, high doses are required to get a small amount of the drug into the brain. What remains in the bloodstream has significant side effects. Often, this discomfort leads the patient to stop the treatment. The use of nanoparticles, which encapsulate the drugs, would result in fewer collateral side effects while increasing brain efficiency.
To prove the effectiveness of this method, the research team first tested it on cultured cells, then on zebrafish. “This species offers several advantages. Its blood-brain barrier is similar to that of humans and its transparent skin makes it possible to see nanoparticles’ distribution almost in real time,” says Professor Ramassamy, Chairholder of the Louise and André Charron Research Chair on Alzheimer’s disease, from the Fondation Armand-Frappier.
Using in vivo tests, researchers were able to observe the crossing of the blood-brain barrier. They also confirmed the absence of toxicity in the library of selected nanoparticles. “We made the particles with polylactic acid (PLA), a biocompatible material that is easily eliminated by the body. A layer of polyethylene glycol (PEG) covers these nanoparticles and makes them invisible to the immune system, so they can longer circulate in the bloodstream,” he explains.
The findings have been published in the Journal of Controlled Release.
Breaking from its tentative recommendations on mask use thus far, the Centers for Disease Control and Prevention (CDC) said on Tuesday that using masks benefits wearers, which is a step beyond its previous declaration that said wearing masks would only protect those around them.
“Experimental and epidemiological data support community masking to reduce the spread” of the virus, the C.D.C. said in a document that details scientific evidence supporting mask use. “Individual benefit increases with increasing community mask use,” it said.
The unequivocal statements are a departure from the agency’s previous language, which suggested that “the latest science may convince” Americans to wear masks and that mask use could prevent an infected person from spreading the virus to others. “The main protection individuals gain from masking occurs when others in their communities also wear face coverings,” it said.
The agency also offered an economic argument, saying that increasing the proportion of people who wear masks by 15 percent could prevent the need for lockdowns and cut associated losses of up to $1 trillion, or about 5 percent of gross domestic product. The document also referred to a study of 124 Beijing households in which mask use significantly cut transmission of the virus, and an outbreak aboard the U.S.S. Theodore Roosevelt in which face coverings appeared to have reduced risk of infection by 70 percent.
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.”
Denmark set off alarm bells this week with its announcement that it is culling the nation’s entire mink herd — the largest in the world — to stop spread of the SARS-CoV-2 virus in the prized fur species because of potentially dangerous mutations. Inter-species jumps of viruses make scientists nervous — as do suggestions of potentially significant mutations that result from those jumps. In this case, Danish authorities say they’ve found some genetic changes that might undermine the effectiveness of Covid-19 vaccines currently in development. But is this latest twist in the Covid-19 saga reason to be deeply concerned?
“This hits all the scary buttons,” noted Carl Bergstrom, an evolutionary biologist at the University of Washington. But Bergstrom and others argued that while the virus’s penchant for infecting mink bears watching, it isn’t likely to lead to a nightmare strain that is more effective at infecting peoplethan the current human virus.
“I don’t believe that a strain which gets adapted to mink poses a higher risk to humans,” said Francois Balloux, director of University College London’s Genetics Institute. “We can never rule out anything, but in principle it shouldn’t. It should definitely not increase transmission. I don’t see any good reason why it should make the virus more severe,” he said.
Let’s take a look at what’s known about the Danish situation, why inter-species jumps make scientists nervous, whether the mutations are likely to affect vaccine effectiveness, and why Balloux thinks this situation is “fantastically interesting.” Denmark is the world’s largest producer of mink — by some estimates 40%. Unfortunately, mink are susceptible to the SARS-2 virus, a fact that came to light in April when the Netherlands reported outbreaks on mink farms there. Infected humans who work in the farms transmit the virus to captive minks, which are housed in close quarters ideal for rapid transmission from mink to mink.
Occasionally, the mink infect people — a phenomenon recorded in both the Netherlands and in Denmark. In a statement, the Danish Ministry of Environment and Food said the country would cull its entire herd — estimated to be about 17 million animals — after finding mutations in the viruses from the mink that it believes would allow those viruses to evade the immune protection generated by Covid-19 vaccines.
Scientists have found a new way to regenerate damaged optic nerve cells taken from mice and grown in a dish. This exciting development could lead to potential eye disease treatments in the future. Damage to full-grown nerve cells causes irreversible and life-altering consequences, because once nerve fibres mature, they lose their ability to regenerate after injury or disease. The new experiments show how activating part of a nerve cell’s regenerative machinery, a protein known as protrudin, could stimulate nerves in the eye to regrow after injury.
With more research, the achievement is a step towards future treatments for glaucoma, a group of eye diseases which cause vision loss by damaging the optic nerve (that links the eye to the brain).
“What we’ve seen is the strongest regeneration of any technique we’ve used before,” said ophthalmologist Keith Martin from the University of Melbourne in Australia. “In the past it seemed impossible we would be able to regenerate the optic nerve but this research shows the potential of gene therapy to do this.”
In this study, scientists stimulated nerve cells of the eye to produce more protrudin, to see if this would help protect the cells from damage and even repair after injury. First, in optical nerve cells cultured in a dish, the researchers showed that ramping up protrudin production stimulated regeneration of nerve cells that had been cut by a laser. Their spindly axons regenerated over longer distances, and in less time, than untreated cells. Next, adult mice were administered gene therapy – an injection straight into the eye – carrying instructions for nerve cells to bump up protrudin production. As painful as that sounds, this procedure can actually be done safely in people (the injection, that is, not yet the gene therapy).
A few weeks and one optic nerve injury later, these mice had more surviving nerve cells in their retinas than the control group did. In one final experiment, the scientists used whole retinas from mice removed two weeks after giving them a protrudin boost, to see if this treatment could prevent nerve cells from dying in the first place. The researchers found, three days later, that stimulating protrudin production had been almost “entirely neuroprotective, with these retinas exhibiting no loss of [retinal] neurons,” the researchers wrote in their paper. Usually, about half of retinal neurons removed in this way die within a couple of days.
“Our strategy relies on using gene therapy – an approach already in clinical use – to deliver protrudin into the eye,” said Veselina Petrova, a neuroscience student at the University of Cambridge. “It’s possible our treatment could be further developed as a way of protecting retinal neurons from death, as well as stimulating their axons to regrow.”
Immunotherapies, such as checkpoint inhibitor drugs, have made worlds of difference for the treatment of cancer. Most clinicians and scientists understand these drugs to act on what’s known as the adaptive immune system, the T cells and B cells that respond to specific threats to the body.
New research from an international team co-led by George Hajishengallis of the University of Pennsylvania School of Dental Medicine suggests that the innate immune system, which responds more generally to bodily invaders, may be an important yet overlooked component of immunotherapy’s success.
Their work, published in the journal Cell, found that “training” the innate immune system with β-glucan, a compound derived from fungus, inspired the production of innate immune cells, specifically neutrophils, that were primed to prevent or attack tumors in an animal model.
“The focus in immunotherapy is placed on adaptive immunity, like checkpoint inhibitors inhibit the interaction between cancer cells and T cells,” says Hajishengallis, a co-senior author on the work. “The innate immune cells, or myeloid cells, have not been considered so important. Yet our work suggests the myeloid cells can play a critical role in regulating tumor behavior.”
The current study builds on earlier work published in Cell by Hajishengallis and a multi-institutional team of collaborators, which showed that trained immunity, elicited through exposure to exposure to the fungus-derived compound β-glucan, could improve immune recovery after chemotherapy in a mouse model.
In that previous study, the researchers also showed that the “memory” of the innate immune system was held within the bone marrow, in hematopoetic stem cells that serve as precursors of myeloid cells, such as neutrophils, monocytes, and macrophages.