Microvascular Injury in the Brains of Patients with Covid-19

 

TO THE EDITOR:

We conducted postmortem high-resolution magnetic resonance imaging (magnetic resonance microscopy) of the brains of patients with coronavirus disease 2019 (Covid-19) (median age, 50 years) and histopathological examination that focused on microvascular changes in the olfactory bulb and brain stem. (See the Materials and Methods section in the Supplementary Appendix, available with the full text of this letter at NEJM.org.) Images were obtained from the brains of 13 patients with the use of an 11.7-Tesla scanner at a resolution of 25 μm for the olfactory bulb and at a resolution of 100 μm for the brain. Abnormalities were seen in the brains of 10 patients. We examined the brains of patients that showed abnormalities by means of multiplex fluorescence imaging (in 5 patients) and by means of chromogenic immunostaining (in 10 patients). We performed conventional histopathological examination of the brains of 18 patients. Fourteen patients had chronic illnesses, including diabetes and hypertension, and 11 had been found dead or had died suddenly and unexpectedly. Of the 16 patients with available medical histories, 1 had delirium, 5 had mild respiratory symptoms, 4 had acute respiratory distress syndrome, 2 had pulmonary embolism, and the symptoms were not known in 3 (Table S1 in the Supplementary Appendix).

Magnetic resonance microscopy showed punctate hyperintensities in 9 patients, which represented areas of microvascular injury and fibrinogen leakage. These features were observed on corresponding histopathological examination performed with the use of fluorescence imaging (Figure 1A and 1B). These areas showed thinning of the basal lamina of the endothelial cells, as determined by collagen IV immunostaining in 5 patients (Fig. 1B1 and 1B2). Punctate hypointensities on imaging in 10 patients corresponded to congested blood vessels (Figure 1C) with surrounding areas of fibrinogen leakage (Figure 1D and Fig. S1) and relatively intact vasculature (Figure 1E). Areas of linear hypointensities were interpreted as microhemorrhages (Figure 1F and Fig. S2). There was minimal perivascular inflammation in the specimens examined, but there was no vascular occlusion, as previously described in the Journal.1 Perivascular-activated microglia, macrophage infiltrates, and hypertrophic astrocytes were seen in 13 patients (Figure 1G and 1H, Fig. S3, and Table S4).2 There were CD3+ and CD8+ T cells in the perivascular spaces and in lumens adjacent to endothelial cells in 8 patients, which may have contributed to vascular injury (Figure 1I and 1J), as suggested in a previous report.3 Activated microglia were found adjacent to neurons in 5 patients, which is suggestive of neuronophagia in the olfactory bulb, substantia nigra, dorsal motor nucleus of the vagal nerve, and the pre-Bötzinger complex in the medulla, which is involved in the generation of spontaneous rhythmic breathing (Figure 1K through 1N and Fig. S3).

Severe acute respiratory syndrome coronavirus 2 was not detected by means of polymerase chain reaction with multiple primer sets, RNA sequencing of several areas of the brain, or RNA in situ hybridization and immunostaining (Table S5). It is possible that the virus was cleared by the time of death or that viral copy numbers were below the level of detection by our assays.

In a convenience sample of patients who had died from Covid-19, multifocal microvascular injury was observed in the brain and olfactory bulbs by means of magnetic resonance microscopy, histopathological evaluation, and immunohistochemical analysis of corresponding sections, without evidence of viral infection. These findings may inform the interpretation of changes observed on magnetic resonance imaging of punctate hyperintensities and linear hypointensities in patients with Covid-19. Because of the limited clinical information that was available, no conclusions can be drawn in relation to neurologic features of Covid-19.

Myoung-Hwa Lee, Ph.D.
National Institute of Neurological Disorders and Stroke, Bethesda, MD

Daniel P. Perl, M.D.
Uniformed Services University of the Health Sciences, Bethesda, MD

Govind Nair, Ph.D.
Wenxue Li, Ph.D.
Dragan Maric, Ph.D.
Helen Murray, Ph.D.
Stephen J. Dodd, Ph.D.
Alan P. Koretsky, Ph.D.
National Institute of Neurological Disorders and Stroke, Bethesda, MD

Jason A. Watts, M.D., Ph.D.
Vivian Cheung, M.D.
University of Michigan, Ann Arbor, MI

Eliezer Masliah, M.D.
National Institute on Aging, Bethesda, MD

Iren Horkayne-Szakaly, M.D.
Robert Jones, M.D.
Defense Health Agency, Silver Spring, MD

Michelle N. Stram, M.D.
Office of Chief Medical Examiner, New York, NY

Joel Moncur, M.D.
Defense Health Agency, Silver Spring, MD

Marco Hefti, M.D.
University of Iowa, Iowa City, IA

Rebecca D. Folkerth, M.D.
Office of Chief Medical Examiner, New York, NY

Avindra Nath, M.D.
National Institute of Neurological Disorders and Stroke, Bethesda, MD
natha@ninds.nih.gov

Supported by intramural funds (K23NS109284 [to Dr. Hefti]) from the National Institute of Neurological Disorders and Stroke. The reagent used in this study (Genomic RNA from SARS-CoV-2, Isolate USA-WA1/2020, NR-52285) was deposited by the Centers for Disease Control and Prevention and obtained through BEI Resources Repository of the National Institute of Allergy and Infectious Diseases of the National Institutes of Health.

Disclosure forms provided by the authors are available with the full text of this letter at NEJM.org.

https://www.nejm.org/doi/10.1056/NEJMc2033369

Monitor for COVID-19 vaccine resistance evolution during clinical trials

 

• David A. Kennedy ,
• Andrew F. Read

DOI: 

• https://doi.org/10.1371/journal.pbio.3001000

PDF: https://journals.plos.org/plosbiology/article/file?id=10.1371/journal.pbio.3001000&type=printable

Abstract

Although less common than the evolution of antimicrobial drug resistance, vaccine resistance can and has evolved. How likely is it that COVID-19 vaccines currently in development will be undermined by viral evolution? We argue that this can be determined by repurposing samples that are already being collected as part of clinical trials. Such information would be useful for prioritizing investment among candidate vaccines and maximizing the potential long-term impact of COVID-19 vaccines.

Funding: The ideas presented here were developed during work funded by the Institute of General Medical Sciences, National Institutes of Health and United Kingdom Biotechnology and Biological Sciences Research Council as part of the NSF-NIH-USDA Ecology and Evolution of Infectious Diseases program (R01GM105244) to AFR and (R01GM140459) to DAK. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.

https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.3001000

COVID-19 vaccines focus on spike protein – but here's another target

 The latest results from the phase 3 COVID-19 vaccines trials have been very positive. These have shown that vaccinating people with the gene for SARS-CoV-2 spike protein can induce excellent protective immunity.

The spike protein is the focus of most COVID-19 vaccines as it is the part of the virus that enables it to enter our cells. Virus replication only happens inside cells, so blocking entry prevents more virus being made. If a person has antibodies that can recognize the spike protein, this should stop the virus in its tracks.

The three most advanced vaccines (from Oxford/AstraZeneca, Pfizer/BioNTech and Moderna) all work by getting our own cells to make copies of the virus spike protein. The Oxford vaccine achieves this by introducing the spike protein gene via a harmless adenovirus vector. The other two vaccines deliver the spike protein gene directly as mRNA wrapped in a nanoparticle. When our own cells make the spike protein, our immune response will recognize it as foreign and start making antibodies and T cells that specifically target it.

However, the SARS-CoV-2 virus is more complicated than just a spike protein. There are, in fact, four different proteins that form the overall structure of the virus particle: spike, envelope (E), membrane (M) and nucleocapsid (N). In a natural infection, our immune system recognizes all of these proteins to varying degrees. So how important are immune responses to these different proteins, and does it matter that the first vaccines will not replicate these?

Following SARS-CoV-2 infection, researchers have discovered that we actually make the most antibodies to the N protein – not the spike protein. This is the same for many different viruses that also have N proteins. But how N protein antibodies protect us from infection has been a long-standing mystery. This is because N protein is only found inside the virus particle, wrapped around the RNA. Therefore, N protein antibodies cannot block virus entry, will not be measured in neutralization assays that test for this in the lab, and so have largely been overlooked.

Parts of the coronavirus, including the N protein. Credit: OSweetNature/ShutterstocWhereas antibodies are typically thought to only work outside of cells, TRIM21 is only found inside cells. We have shown that N protein antibodies that get inside cells are recognized by TRIM21, which then shreds the associated N protein. Tiny fragments of N protein are then displayed on the surface of infected cells. T cells recognize these fragments, identify cells as infected, then kill the cell and consequently any virus.

We expect that this newly identified role for N protein antibodies in protecting against virus infection is important for SARS-CoV-2, and work is ongoing to explore this further. This suggests that vaccines that induce N protein antibodies, as well as spike antibodies, could be valuable, as they would stimulate another way by which our immune response can eliminate SARS-CoV-2.

Adding N protein to SARS-CoV-2 vaccines could also be useful because N protein is very similar between different coronaviruses—much more so than the spike protein. This means it's possible that a protective immune response against SARS-CoV-2 N protein could also offer some protection against other related coronaviruses, such as Mers.

Another potential benefit that may arise from including N protein in SARS-CoV-2 vaccines is due to the low mutation rates seen in the N protein sequence. Some changes to the sequence of SARS-CoV-2 have been reported over the course of this pandemic, with the most significant changes occurring in the spike protein. There is some concern that if the spike sequence alters too much, then new vaccines will be required. This could be similar to the current need for annual updating of influenza vaccines. However, as the N protein sequence is much more stable than the spike, vaccines that include a component targeting the N protein are likely to be effective for longer.

The first wave of SARS-CoV-2 vaccines brings genuine hope that this virus can be controlled by vaccination. From here it will be an ongoing quest to develop even better vaccines and ones that can remain effective in the face of an evolving virus. Future vaccines will probably focus on more than just the spike protein of SARS-CoV-2, and the N protein is a promising target to add to the current strategies being considered.

https://medicalxpress.com/news/2020-12-covid-vaccines-focus-spike-protein.html

Flurry of international orders for Chinese covid vaccines

 

• At least 10 countries have signed up for the shots from Sinopharm and other providers
• It’s an opportunity for Beijing to burnish its global reputation but it all depends on transparency, observers say
• Pakistan and Hungary were among the string of countries lining up to order coronavirus vaccines from China as Chinese regulators 

  approved the country’s first Covid-19 shot.

  The vaccine, developed under state-owned Sinopharm, was approved for conditional market use on Thursday after reporting 

  79 per cent efficacy

   against the disease in interim results, according to Chinese health officials who gave few details about how the assessment was made.

  The approval is a milestone for Beijing, which has played up its plans to make its vaccines a “global public good” and could make a big difference to the very limited supplies, according to analysts.

  At least 10 countries in Latin America, the Middle East and Asia have signed up for doses from China’s vaccine developers, which also include Sinovac Biotech and CanSino Biologics.

  A day earlier Ukraine signed a contract to buy 1.8 million doses from Sinovac. The company has yet to announce results of its global trials, but, like Sinopharm, was granted emergency use authorisation in China in July.

  Drew Thompson, a visiting senior research fellow at the Lee Kuan Yew School of Public Policy at the National University of Singapore, said supplying vaccines was “an important benchmark for China in terms of its status”.

  Dominic Meagher, a visiting fellow at the Australian National University, agreed that it would be a “win for China” and global public health if China could successfully roll out Chinese vaccines.

  But it was a highly complex task and it was not clear how it would play out, he said.

  “Until people are actually vaccinated safely and effectively, it’s a promise,” said Meagher, who is researching China’s response to Covid-19.

  Egypt is also among countries to already receive doses of the Sinopharm vaccine. Its health ministry signed a letter of intent for Covid-19 vaccine cooperation with China on Thursday, according to the Chinese embassy in Cairo.

  Along with Morocco, Egypt is expected to be a production centre for Covid-19 distribution in Africa.

  One of the Sinopharm vaccine’s advantages is that it can be stored and transported at normal fridge temperatures. If competitively priced, the vaccine could be a “game changer” in the sector, according to global health governance researcher Sara Davies.

  But officials have released very little information about the analysis of the vaccine, saying only that trials included 60,000 people in several countries, mild fever occurred in less than 0.1 per cent of the participants and there was a serious allergic reaction in about two per million.

  The vaccine has yet to be endorsed by the World Health Organization, a gold standard for domestic regulators and UN agencies placing vaccine orders.

  That might be the next hurdle for the Sinopharm vaccine, according to Davies.

  “It’s one thing to be able to get countries signing on. It’s another to say you are a leader – to do that there has to be transparency and that international seal of approval,” she said.

• Pakistan joined that list with an announcement on Thursday, saying it planned to buy 1.2 million doses from the company. The two-dose jabs, enough to cover 600,000 people, are the country’s first official confirmation of a vaccine purchase.
• Hungary also expressed interest in Covid-19 vaccines from China, with a senior official saying the country planned to rely on shots obtained directly from China or through a European Union procurement mechanism.
• Observers said that by supplying vaccines to the rest of the world, China had a chance to bolster its international reputation and partnerships.
• “It’s definitely a point of prestige for China to have vaccines, not just for its domestic needs, but to provide abroad, just like the major US pharmaceutical companies and Russia pharmaceutical companies,” Thompson said.
• Sinopharm’s vaccines are already 

  in use in the United Arab Emirates

   and Bahrain, countries that hosted clinical trials for the shots. Both countries gave emergency use authorisation for the doses, followed by approval earlier last month.
• “It’s got all the bells and whistles to be a big deal, but we just need more information. It’s really important if China wants to claim leadership [in global vaccine supply] and reach a bigger market, they are going to have to start coming forward with a lot more information,” said Davies, a professor at Griffith University in Australia.
• An executive from Sinopharm subsidiary China National Biotec Group, which is responsible for developing the vaccine, said more details would be released and published in scientific journals.
• On Thursday, the WHO gave its first emergency use validation for a Covid-19 vaccine to Pfizer-BioNTech.

• https://www.scmp.com/news/china/science/article/3116135/coronavirus-flurry-international-orders-chinese-vaccines

Large population study identifies drugs associated with reduced COVID-19 severity

  

View ORCID ProfileAriel Israel, Alejandro A. Schäffer,  View ORCID ProfileAssi Cicurel, Ilan Feldhamer, Ameer Tal,  View ORCID ProfileKuoyuan Cheng, Sanju Sinha, Eyal Schiff, Gil Lavie,  View ORCID ProfileEytan Ruppin

doi: https://doi.org/10.1101/2020.10.13.20211953

This article is a preprint and has not been peer-reviewed [what does this mean?]. It reports new medical research that has yet to be evaluated and so should not be used to guide clinical practice.

PDF: https://www.medrxiv.org/content/10.1101/2020.10.13.20211953v2.full.pdf

Abstract

BACKGROUND It may take months to years until drugs specifically designed to treat COVID-19 are available. Until then, it is crucial to identify whether existing medications could have a protective effect against severe disease. This is the objective of this large population study performed in Clalit Health Services (CHS), the largest healthcare provider in Israel.

METHODS CHS centrally manages electronic health records (EHRs) including medication purchases for over 4.5 million members. Two case-control matched cohorts were assembled to assess systematically which drugs affected the risk of COVID-19 hospitalization: in both cohorts, case patients were hospitalized for COVID-19; matched control patients were taken from the general population in the first cohort, and non-hospitalized SARS-CoV-2 positive patients in the second cohort. For each medication anatomical-therapeutic-chemical (ATC) class acquired during the last month before the index-date, we computed the odds ratio (OR) for hospitalization, 95% confidence interval (CI), and the p-value, using Fisher’s exact test. False discovery rate was used to adjust for multiple testing.

RESULTS Several drugs and pharmacy sold items were associated with significantly reduced odds for SARS-CoV-2 hospitalization, notably ubiquinone (OR=0.185, 95% CI [0.058,0.458], p<0.001), ezetimibe (OR=0.513, 95% CI [0.375,0.688], P<0.001), rosuvastatin (OR=0.746, 95% CI [0.645,0.858], p<0.001) and flecainide (OR=0.303, 95% CI [0.080,0.813], p<0.01). Additionally, acquisition of surgical masks, latex gloves and several ophthalmological products were associated with decreased risk for hospitalization.

CONCLUSION Ubiquinone, ezetimibe and rosuvastatin, all related to the cholesterol synthesis pathway were associated with reduced hospitalization risk. These findings suggest a promising protective effect which should be further investigated.

Competing Interest Statement

The authors have declared no competing interest.

Funding Statement

This research was supported in part by the Intramural Research Program of the National Institutes of Health, NCI.

https://www.medrxiv.org/content/10.1101/2020.10.13.20211953v2

'No need to panic,' China official says of coronavirus variants

 There is no sign new coronavirus variants will affect the immune impact of a vaccine that China has just authorised for public use, a disease control official was quoted as saying on Friday.

The shot by an affiliate of state-backed company Sinopharm was approved on Thursday, the day after news of China's first imported case of a variant spreading in Britain.

"No need to panic," Xu Wenbo, an official at the Chinese Center for Disease Control and Prevention (CDC), told state TV.

"The mutated variant, compared with previous mutated variants .... has no obvious change so far in its ability to cause disease," he added.

He said no impact of variants on the vaccine's immune effect had been detected.

The variant which British scientists have named "VUI – 202012/01" includes a genetic mutation in the "spike" protein, which could theoretically result in easier spread of COVID-19.

Xu added that mutation in the virus' protein would not effect the sensitivity of most Chinese-made COVID-19 tests that target the virus' nucleic acids, which carry genetic information.

https://www.marketscreener.com/news/latest/No-need-to-panic-China-official-says-of-coronavirus-variants--32109321/

Hospitals May Consider Relaxing No-Visitor Policies During Pandemic

 As the COVID-19 pandemic continues, hospitals should consider whether their visitor policies are too restrictive and potentially adopt more nuanced policies that account for community transmission of the virus, careful use of personal protective equipment and vaccine status, according to a group of doctors in Canada.

Many hospitalized patients lacked support this year and struggled emotionally, particularly in intensive-care units, the group writes in the Canadian Medical Association Journal.

"Despite how busy our ICUs were during the first wave of the pandemic, the absence of family presence was palpable," said lead author Dr. Laveena Munshi of Mount Sinai Hospital in Toronto.

"Families and designated care partners are essential members of patient-centered care in the ICU and their role extends beyond comfort," she told Reuters Health by email. "They are patient advocates, they help minimize the impact of delirium, they listen in on our daily ICU rounds and add their insight, and they are substitute decision makers during times when we cannot communicate with patients."

Dr. Munshi and colleagues discuss the research behind hospital visitor policies, ways to bring family members to the bedside safely and how to communicate with family members if they can't visit. During the first wave of the pandemic, they found, hospitals across Canada adopted "no visitor" policies that barred nearly all visitors in an effort to prevent the spread of COVID-19 and reserve personal protective gear for healthcare providers.

As scientists and public-health researchers have learned more about COVID-19, though, more flexible policies may be useful, the authors suggest. Previous studies of visitor policies for the flu and other respiratory diseases found that the benefits of allowing visitors outweigh the harms, especially when visitors wear masks.

Studies have shown that family members and caregivers provide emotional support, help with language barriers, play a role in end-of-life decisions and assist with daily activities such as feeding and mobility.

Hospitals could adapt their policies to distinguish between general visitors and immediate family members or designated caregivers, the authors write, and allow certain visitors in ICUs, hospices, surgical recovery wards and labor and delivery units. Face masks, rigorous cleaning procedures and visitor screening with rapid COVID-19 tests could help as well.

Hospitals should also consider the best ways to communicate with family members and caregivers as the pandemic continues, the authors write. In areas with a high rate of COVID-19 transmission or in instances where visitors aren't allowed, healthcare workers could use video conferencing tools to allow patients to connect with others. When feasible, some hospitals may be able to coordinate visits in outdoor spaces.

"Open communication is foundational to establishing a therapeutic relationship between healthcare providers and the patients and families they serve," said Dr. Joanne Gould Kuntz of the Emory University Hospital in Atlanta, Georgia. Dr. Kuntz, who wasn't involved with the new paper, has researched virtual family meetings for palliative care during the pandemic.

"While video virtual visits do help . . . there is no equal substitute for in-person visitors that can replicate the safety, support and communication that occurs when key family members are able to be present at the bedside," she told Reuters Health by email.

As the pandemic continues in the months ahead, hospitals need a tailored approach based on local and regional infections and should potentially consider visitors' COVID-19 vaccine status, the authors write.

"I am hopeful that widespread vaccination in the coming months will not only reduce the overall infection rates of COVID-19 but also facilitate a return to more normal hospital policies," said Dr. Jordan Cloyd of the Ohio State University Wexner Medical Center in Columbus, who has researched COVID-19 visitor policies and the effect on surgery patients.

"As we embrace another surge of COVID-19 and are set to begin the second year of this pandemic, it is important to modify our policies to reflect what we have learned over the past year in order to optimally balance the benefits and risks to patients, staff and our communities," Dr. Cloyd, who also was not involved with the new report, told Reuters Health by email.

https://www.medscape.com/viewarticle/943208