Genome-wide CRISPR screen identifies host factors that regulate SARS-CoV-2 entry

 

Yunkai Zhu, 

Fei Feng, 

Gaowei Hu, 

Yuyan Wang, 

Yin Yu, 

Yuanfei Zhu, 

Wei Xu, 

Xia Cai, 

Zhiping Sun, 

Wendong Han, 

Rong Ye, 

Di Qu, 

Qiang Ding, 

Xinxin Huang, 

Hongjun Chen, 

Wei Xu, 

Youhua Xie, 

Qiliang Cai, 

Zhenghong Yuan & 

Rong Zhang 

DOIhttps://doi.org/10.1038/s41467-021-21213-4

PDF: https://www.nature.com/articles/s41467-021-21213-4.pdf

Abstract

The global spread of SARS-CoV-2 is posing major public health challenges. One feature of SARS-CoV-2 spike protein is the insertion of multi-basic residues at the S1/S2 subunit cleavage site. Here, we find that the virus with intact spike (Sfull) preferentially enters cells via fusion at the plasma membrane, whereas a clone (Sdel) with deletion disrupting the multi-basic S1/S2 site utilizes an endosomal entry pathway. Using Sdel as model, we perform a genome-wide CRISPR screen and identify several endosomal entry-specific regulators. Experimental validation of hits from the CRISPR screen shows that host factors regulating the surface expression of angiotensin-converting enzyme 2 (ACE2) affect entry of Sfull virus. Animal-to-animal transmission with the Sdel virus is reduced compared to Sfull in the hamster model. These findings highlight the critical role of the S1/S2 boundary of SARS-CoV-2 spike protein in modulating virus entry and transmission and provide insights into entry of coronaviruses.

https://www.nature.com/articles/s41467-021-21213-4

White House: Holding onto AstraZeneca COVID-19 shots for Americans

 The White House is holding onto some doses of AstraZeneca Plc’s COVID-19 vaccine so they can be given to Americans quickly if authorized by the U.S. health regulator, a top administration official said Friday.

AstraZeneca has produced doses of its COVID-19 vaccine in the United States, where it has yet to be approved. The vaccine developed with Oxford University has been authorized for use in the European Union and many other countries.

Reuters reported this week that U.S. officials told the EU not to expect shipments of the shot from the United States anytime soon.

“We have a small inventory of AstraZeneca so, if approved, we can get that inventory out to the American people,” White House COVID-19 response coordinator Jeffrey Zients said in a Friday press call.

The New York Times reported this week that tens of millions of doses have already been produced in the United States and are sitting in production facilities unused.

AstraZeneca said in February it expects its vaccine could receive U.S. emergency use authorization at the beginning of April and could immediately deliver 30 million doses to locations around the United States.

The U.S. stance could jeopardize AstraZeneca’s attempts to come closer to delivering on its contractual obligation with the EU of 180 million doses in the second quarter.

AstraZeneca told the EU earlier this year it would cut its supplies in the second quarter by at least half to less than 90 million doses, EU sources told Reuters, after a bigger reduction in the first three months of the year.

U.S. President Joe Biden said on Wednesday the government will first give Americans COVID-19 vaccines, but any surplus would be shared with the world.

“We...want to make sure we have maximal flexibility, that we are oversupplied and over-prepared and that we have the ability to provide vaccines, whatever the most effective ones are, to the American public,” White House press secretary Jen Psaki told reporters on Friday.

“A number of countries... have requested doses from the United States and we have not provided doses from the U.S. government to anyone,” she added.

The United States has been one of the world leaders in vaccine administration. It has distributed more than 130 million shots and administered nearly 100 million, according to federal data last updated on Thursday.

White House officials said on Friday that 65% of Americans over 65 years old have been given shots.

https://www.reuters.com/article/us-health-coronavirus-whitehouse-astraze/white-house-says-its-holding-onto-astrazeneca-covid-19-shots-for-americans-idUSKBN2B42AL

AstraZeneca Warns Europe of Large Delivery Shortfall, Blaming Export Curbs

 AstraZeneca PLC has warned European Union officials it no longer expects to supply the bloc with around 100 million Covid-19 shots it pledged to bring in from overseas in coming months, worsening a vaccine-supply crisis on the continent as cases rise again and governments consider new lockdown measures.

The shortfall represents enough of the two-dose shots to vaccinate 50 million people, or well over 10% of the bloc's population. It threatens to sap the EU's already strained ability to roll out effective vaccine drives among its 27 member states.

"It's time for AstraZeneca's Board to exercise its fiduciary responsibility and now do what it takes to fulfill AZ's commitments," Thierry Breton, France's European Commissioner who is leading the bloc's vaccine strategy, said on Twitter on Thursday.

U.K.-based AstraZeneca earlier this year had already greatly reduced its estimate of doses it expected to deliver to Europe in the first quarter of the year because of manufacturing problems it experienced in a plant in Europe. Its backup plan involved trying to supplement European-made supply with doses the company and its partners have been making overseas.

Production has been humming in the U.K. and India. In the U.S., a stockpile of doses that AstraZeneca says should reach 50 million by the end of April has gone unused because the shot isn't yet approved by the Food and Drug Administration.

AstraZeneca on Friday said unspecified export restrictions now rendered plans to bring in large amounts of doses made outside Europe unlikely. It said it now expects to provide 100 million doses to the EU in the first half of this year, down from earlier commitments of around 270 million.

The EU said this week it expects to receive a total of 100 million doses of vaccines a month from the vaccine makers with which it has supply contracts during the second quarter. The bloc is sticking to that estimate, an EU official said after AstraZeneca's announcement.

The bloc has also bought shots from Pfizer Inc. and Moderna Inc. On Thursday, Europe's top medicines agency approved another vaccine, delivered in a single shot, made by Johnson & Johnson.

"It is absolutely clear that supplementary efforts are needed by [AstraZeneca] in order to meet its targets," the European Commission chief spokesman, Eric Mamer, said Friday.

Amid AstraZeneca's production woes in January, company executives debated the possibility of sending U.S.-made shots to Europe as a temporary measure, ahead of any U.S. authorization of the vaccine, The Wall Street Journal previously reported. But the company at the time considered that unlikely because it would require U.S. government permission.

EU officials told member states this week that U.S.-made shots wouldn't be available to Europe in the short term, a person briefed on the discussions said.

The White House's coordinator for Covid-19, Jeff Zients, told reporters on Friday that the AstraZeneca doses in the U.S. are being kept in the country.

"We have a small inventory of AstraZeneca so that, if approved, we can get that inventory out to the American people as quickly as possible," he said. AstraZeneca is expecting results of large-scale U.S. clinical trials this month, a step in preparing to apply for U.S. regulatory approval.

The EU, which has sent 9 million vaccine doses to the U.K. since late January, has accused the U.K. of banning vaccine exports to Europe. U.K. officials have denied that. The U.K. government has said it is up to manufacturers whether doses are exported, and hasn't said whether any have.

AstraZeneca, which developed its shot with the University of Oxford, promised to deliver 3 billion doses to countries around the world this year, at no profit. That scale and pricing pledge set it apart from other vaccine makers. That has also made it a key plank in many countries' vaccine rollout plans.

But the vaccine has been beset by early confusion over results of late-stage human trials. The AstraZeneca shot was shown to work against Covid-19 less effectively than Pfizer and Moderna shots. France and Germany initially restricted its distribution to older people because of a lack of trial data.

More recently, real world data in the U.K. showed the shot to be about as effective as Pfizer's in older Britons. Germany and France, struggling with vaccine rollouts, reversed themselves and allowed the shot to be used in older people.

The manufacturing setbacks in Europe also dented AstraZeneca's credibility. AstraZeneca Chief Executive Pascal Soriot has repeatedly pushed back against doubts about the shot's efficacy compared with others, and criticism of its rollout. AstraZeneca said last month it would roughly double global vaccine production to 200 million doses a month by April.

"Is it perfect?" Dr. Soriot told journalists in an earnings briefing. "No, it's not perfect, but it's great, and tell me who else is making 100 million doses in the month of February."

While Brussels faces pressure from EU capitals to speed up delivery of doses, the European Commission has highlighted the bloc's contributions to global supplies. Officials said Thursday that member states had shipped out 34 million doses of vaccines to the U.K., the U.S. and other countries since late January.

The bloc, too, has faced criticism for restricting shipments of doses overseas. Last week, Italy, with EU backing, blocked the export of 250,700 AstraZeneca doses to Australia, exercising an optional export ban for the first time since its introduction in late January. The doses had been bottled at a factory near Rome that is part of the drugmaker's supply chain.

Italian officials framed the move as a response to AstraZeneca's European supply shortfall. AstraZeneca didn't comment at the time. Italian officials said the company had delivered 1.5 million doses to Italy.

On Thursday, the EU said it was extending the export ban option until the end of June.

https://www.marketscreener.com/quote/stock/ASTRAZENECA-PLC-4000930/news/AstraZeneca-Warns-Europe-of-Large-Delivery-Shortfall-Blaming-Export-Curbs-32674121/

Healthcare professionals no better than students at detecting COVID fake news stories

 

• Sven Grüner ,
• Felix Krüger

DOI: https://doi.org/10.1371/journal.pone.0247517

PDF: https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0247517&type=printable

Abstract

False news stories cause welfare losses and fatal health consequences. To limit its dissemination, it is essential to know what determines the ability to distinguish between true and false news stories. In our experimental study, we present subjects corona-related stories taken from the media from various categories (e.g. social isolation, economic consequences, direct health consequences, and strong exaggeration). The subject’s task is to evaluate the stories as true or false. Besides students with and without healthcare background, we recruit healthcare professionals to increase the external validity of our study. Our main findings are: (i) Healthcare professionals perform similar to students in correctly distinguishing between true and false news stories. (ii) The propensity to engage in analytical thinking and actively open-minded thinking is positively associated with the ability to distinguish between true and false. (iii) We find that the residence of the subjects (East- or West-Germany) plays only a minor role. (iv) If news stories are in line with existing narratives, subjects tend to think that the stories are true.

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0247517

1st study in nation to enroll kids in trial of novel MIS-C therapy

 A team of pediatricians at the Medical University of South Carolina (MUSC) was the first in the nation to enroll patients with multisystem inflammatory syndrome in children (MIS-C), a rare but life-threatening complication of COVID-19, in a trial of remestemcel-L. This investigational cell therapy, developed and manufactured by Mesoblast, New York, New York, had previously been shown safe and effective for other inflammatory conditions. The MUSC team reports in Pediatrics that the two children enrolled thus far showed significant improvement within 24 hours of remestemcel-L administration.

"While it appears to many people that COVID is no big deal in children, this potential complication, although rare, is very, very serious," said MUSC Children's Health pediatric infectious disease physician, Allison Eckard, M.D., who is leading the local trial. "In South Carolina, we have had over 70 cases of MIS-C and one death. That is way more than we'd like to see in children."

Too often, MIS-C is not recognized until children are already critically ill.

"The tricky part about MIS-C is that, in many cases, the families don't know that the children ever had COVID because, in general, children have very mild symptoms," said Eckard.

MIS-C can also be missed because its symptoms are vague, and so it can easily be mistaken for other illnesses.

Although the cause of MIS-C is unknown, Eckard speculates that the body's reaction to COVID-19 likely sets off a cascade of unchecked inflammation.

"Although inflammation has a role to play in the body, excessive inflammation is bad and causes organ damage, organ failure and a lot of other complications," she said.

The current standard of care for MIS-C is nonspecific. It consists of using steroids or antibodies derived from donated plasma to turn down all aspects of the immune system.

"The novel treatment we are using is a little bit more specific," said Eckard.

Remestemcel-L is a cellular therapy derived from a special type of cell that forms in bone marrow.

"These bone marrow cells, donated by healthy adults, are known to turn down inflammation," said Eckard. They are able to target the specific parts of the immune system that are most relevant to MIS-C.

The cells are also able to improve the inner lining of the blood vessel, targeting the most serious and potentially long-term effects of MIS-C: cardiac and cardiovascular involvement. Remestemcel-L improves blood pressure and the flow of blood to where it needs to be.

"We rely on the heart to pump blood adequately to all the other organs," said Eckard. "The same applies to blood vessels and the cardiovascular system. When they don't work properly, your body can't pump blood effectively to vital organs."

Nationwide studies have already been conducted on the use of remestemcel-L to treat graft-vs-host disease in children, a condition that can develop after receiving a bone marrow transplant, and MUSC participated in some of them. Other studies have also assessed its usefulness for treating cardiac complications in adults. However, MUSC is the only institution thus far to use remestemcel-L for the purpose of MIS-C.

"We always worry in pediatrics about the safety of new therapies. But because of our experience here at MUSC with hundreds of children enrolled in a remestemcel-L trial for graft-vs. host disease, we felt really good about its safety profile," said Eckard.

Thus far, two children have been enrolled in the trial and treated with remestemcel-L. They were chosen because they still had underlying inflammation and cardiac dysfunction despite having received standard-of-care therapy. Eckard hopes that the investigational therapy will help to protect these children from long-term cardiovascular complications.

"People are always very hesitant to try new things if they think the current therapy is working. But what I say to that is we do not know the long-term effects of MIS-C," said Eckard.

Although it is too early to know if the novel therapy will protect against long-term complications, Eckard is heartened by the therapy's short-term effects, which were reported in the Pediatrics article.

"There were some dramatic improvements within 24 hours of giving the treatment in both of the children, and that is what compelled us to publish those two cases," said Eckard.

The remestemcel-L trial for use in MIS-C aims to enroll 50 children with cardiac dysfunction nationwide. If the investigational treatment proves effective at treating MIS-C, it might also be studied in children with other inflammatory syndromes.

Future studies will aim to determine if the administration of remestemcel-L is alone responsible for the improvement of patients or if it still needs to be administered with plasma antibodies, which is the current but more expensive standard of care. The current standard-of-care therapies also have unwanted side effects that might be avoided if remestemcel-L is used instead.

"We want people to be more aware of the condition, but we also want to show people that we've had success with this therapy, in terms of safety and effectiveness, and encourage others to consider using it at their own institutions," said Eckard.

###

Disclosure: One of the article's authors is a consultant to Mesoblast and another is an employee. None of the other authors has conflicts of interest to disclose.

https://www.eurekalert.org/pub_releases/2021-03/muos-mif031021.php

With masks on, 3 feet as safe as 6 feet apart in Mass. schools: study

 As COVID-19 infection rates continue to fall, Massachusetts officials are signaling it's almost time to end remote learning and send all school-aged children back to the classroom. While emerging data suggest young children and schools have not been primary drivers of the COVID-19 pandemic, evidence to guide best practices to prevent the spread of the virus in the school setting has been limited and, as a result, national and international recommendations are inconsistent.

A study led by Beth Israel Deaconess Medical Center (BIDMC) physician-researchers provides new, much-needed data about the optimal physical distancing between students for the prevention of COVID-19 in the school setting. In a retrospective, statewide cohort study, the researchers compared the rates of COVID-19 cases in students and staff in Massachusetts public schools among districts with universal mask mandates but different physical distancing requirements. The team found no substantial difference in the number of cases of COVID-19 among either students or staff in school districts that implemented a distancing policy of three feet versus six feet between students. The findings, published in the journal Clinical Infectious Diseases, suggest that lower physical distancing policies can be adopted in school settings with masking mandates without negatively impacting student or staff safety.

"Prior studies have not directly compared the impact of different physical distancing policies among students attending in-person school," said lead author Polly van den Berg, MD, a fellow in the Division of Infectious Diseases at BIDMC. "This research, which found no substantial difference in the number of cases among either students or staff in school districts that implemented a distancing policy of three versus six feet between students, is important because many school buildings have physical infrastructure that cannot accommodate six feet of distancing and bring all (or most) students back into the classroom."

Van den Berg and colleagues looked at publicly available data from 251 Massachusetts school districts, encompassing 537,336 students and 99,390 staff who attended in-person instruction during a 16-week study period from September 2020 to January 2021. Using a combination of information - including individual district infection control plans, the number of infections reported to the Commonwealth by districts, and community rates of COVID-19 from a non-partisan, not-for-profit data dashboard - the scientists found no significant difference in the rate of COVID-19 cases among students and staff in districts that mandated six feet of distancing versus in districts that mandated three feet of distancing. The scientists note that physical distancing was only one of several infection prevention measures taken by school districts.

"These data can be used to inform and update how infection control plans are implemented in school settings," added corresponding author Westyn Branch-Elliman, MD, MMSc, an infectious disease specialist at BIDMC and a clinical investigator at VA Boston Healthcare System. "It is important to remember that distancing was just one of a number of interventions adopted in the districts included in our analysis. Across the districts included in our study, there was a near-universal masking mandate, thus our study addresses the question of the effectiveness of three versus six feet of distancing among students and staff who are wearing masks."

The team's findings also showed that, in general, schools had lower overall rates of infection than their surrounding communities, lending support to the idea that in-person learning is not a major driver of the pandemic; however, district case rates were tightly linked to those of the community, particularly among staff.

"Early in the pandemic, infection control plans for schools and other settings were developed based on the best available evidence at the time -- which, early on, was limited," said Branch-Elliman, also an Assistant Professor of Medicine at Harvard Medical School. "We hope that our findings can be used to update current recommendations about distancing policy, and ultimately, to help return more students to the classroom."

###

Co-authors include Elissa M. Schechter-Perkins, MD, MPH, of Boston University School of Medicine and Boston Medical Center; Rebecca S. Jack, MPP of COVID-19 School Response Dashboard; Isabella Epshtein, MPP, of VA Boston Center for Healthcare Organization and Implementation Research; Richard Nelson, PhD, Veterans Affairs Salt Lake City Healthcare System and University of Utah School of Medicine; and Emily Oster, PhD, of COVID-19 School Response Dashboard and Brown University Watson Institute for International and Public Affairs.

The authors received no financial support for the research, authorship, and/or publication of this article. WBE is the site PI for a grant funded by Gilead pharmaceuticals (funds to institution). EO and RJ are affiliated with the COVID-19 School Dashboard, which is funded in part by the Chan Zuckerberg Foundation and the Arnold Foundation. All other authors have no conflicts to report.

https://www.eurekalert.org/pub_releases/2021-03/bidm-wmo031121.php

Team Cuomo gave group homes deadly COVID mandate too — still in effect

 It’s truly obscene: Gov. Cuomo not only forced group homes for the intellectually and developmentally disabled to take in the COVID-infected, as he did with nursing homes, he has left the group-home mandate in effect even now, months after publicity shamed him into reversing the nursing-home order.

The gov and his minions are also still stonewalling on the resulting group-home death toll, too, even after they were forced to admit the truth about homes for the elderly.

This makes it obvious that only the Post-led public outcry got Cuomo to drop the nursing-home mandate. It also suggests that his administration thinks the lives of New Yorkers with intellectual or developmental disabilities just don’t matter.

The state’s Office for People With Developmental Disabilities’ directive issued April 10 is strikingly similar to the nursing-home order. It bars residential facilities from denying admission or re-admission to anyone “based solely on a confirmed or suspected diagnosis of COVID-19.” They’re not even allowed to test a hospitalized patient for the virus before admission.

And it appears to have been just as lethal. Group-home residents with intellectual or developmental disabilities were three times more likely to contract the coronavirus and three times more likely to die from it than the general New York population, a months-long investigation conducted by Disability Rights New York, the New York Civil Liberties Union and New York Lawyers for the Public Interest found.

The report, released this week, notes the “daunting task” of minimizing virus spread “in residences where more than a dozen individuals may reside and share bathrooms and other living areas.” Imagine how impossible it must be when a contagious patient is forced into such a living situation. That echoes a study released last year that found intellectually or developmentally disabled group-home residents had more than twice the risk of severe COVID-19 outcomes than New Yorkers in general.

OPWDD reports that more than 6,900 out of nearly 35,000 group-home residents have caught COVID, 552 fatally. But that’s likely an undercount — just like the Department of Health’s nursing-home numbers. And the state for nine months has evaded valid Freedom of Information Law requests for the full data, just as it did on nursing-home info.

Add these abuses to the “reason to impeach NOW” file.

https://nypost.com/2021/03/12/team-cuomo-gave-group-homes-a-deadly-covid-mandate-too-and-its-still-in-effect/