In a recent study published on the medRxiv* preprint server, researchers describe a 16-month-old case of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in an immunocompromised individual.
Following unsuccessful therapy with monoclonal antibody (mAb) bamlanivimab, the individual was found to be infected with a SARS-CoV-2 strain that harbored a unique and previously undetected spike (S) mutation E484T. The viral strain was highly resistant to bamlanivimab but remained susceptible to three other mAbs.
Study: Evolution of a globally unique SARS-CoV-2 Spike E484T monoclonal antibody escape mutation in a persistently infected, immunocompromised individual. Image Credit: Jorieri / Shutterstock.com
The SARS-CoV-2 S residue E484 is nested inside the receptor-binding domain (RBD), which is the target for approximately 90% of neutralizing antibodies (nAbs), particularly Class 2 nAbs. Studies have identified the E484K mutation in SARS-CoV-2 variants of concern (VOC) including the Beta (B.1.351), Gamma (P.1), and Omicron sub-variants B.1.617.1 and P.2, all of which were circulating in 2020.
The widespread prevalence of this mutation led the United States Food and Drug Administration (FDA) to revoke Emergency Use Authorization (EUA) for bamlanivumab in 2021. Studies have comprehensively investigated S E484K mutation and found that it reduced susceptibility to bamlanivimab by more than 2,360-fold.
Typically, the host immune system clears SARS-CoV-2 infection within 15 to 25 days; however, this infection is often prolonged in immunocompromised individuals. Studies have reported such cases, with one previously documented case of prolonged infection lasting 333 days.
It is noteworthy that in cases with prolonged SARS-CoV-2 infection, the virus adapts within the host and gives rise to variants with remarkable antibody resistance and the ability to evade immunity.
The clinical condition of the patient
In the present study, researchers describe the case of an immunocompromised patient in his 50s who first contracted SARS-CoV-2 infection in spring 2020. The patient was admitted to a hospital intensive care unit (ICU) about four months post-diagnosis and received two courses of remdesivir, convalescent plasma, and steroid treatment and yet continued to test positive for the coronavirus disease 2019 (COVID-19) by reverse transcription-polymerase chain reaction (RT-PCR) assay.
A) RT-qPCR cycle threshold values for patient nasopharyngeal swab specimens collected over almost 16 months of follow-up. The red line marks when the patient received the Bamlanivumab intravenous monoclonal antibody treatment (700mg). The dotted line in month 14 indicates a positive PCR test but no available Ct value. Note that Ct values are inverted to correspond with the inverse relationship between PCR Ct threshold value and and nasal RNA copy number. B) Timeline of clinically relevant information for the patient’s chronic infection, including symptoms, therapeutics, and hospitalizations.
About six months after his initial diagnosis, the patient received 700 mg of intravenous bamlanivumab monotherapy. A month later, the patient reported worsening symptoms, including difficulty breathing and fever, with chest CT scans showing organizing pneumonia. At this time, the patient yet again tested positive for COVID-19.
Despite receiving the best care, the patient tested PCR-positive for SARS-CoV-2 up to 16 months post-diagnosis. The patient subsequently received another five-day course of remdesivir and another three infusions of VaxPlasma. Moreover, his cycle threshold (Ct) values remained below 27 in most PCR tests, which indicated active SARS-CoV-2 replication and high viral loads.
It remained unclear whether the patient was experiencing symptoms from persistent SARS-CoV-2 infection or was suffering from post-COVID lung damage due to continuous viral excretion in the respiratory tract.
SARS-CoV-2 isolates from the patient’s nasopharyngeal specimens were sequenced at 12-time points, beginning at around four months post-diagnosis.
From a specimen taken about four months-post diagnoses, 24 mutations were detected in the patient’s virus that was distinct from the ancestral SARS-CoV-2 strain (Wuhan-1). One of the mutations, Envelope T30I, is commonly found in immunocompromised individuals, though this mutation was lost approximately five months post-diagnosis. The number of mutations gradually increased to 40 by the final sequencing timepoint.
A point mutation in S codon 484, persisted in the virus consensus sequence for eight months after diagnosis.
However, after the patient received the bamlanivumab monotherapy, SARS-CoV-2 was not sequenced for more than three months. When the virus was again sequenced, the researchers cultured in vitro infectious viruses from a nasopharyngeal swab and observed 37 consensus mutations from the Wuhan-1 sequence, eleven of which rose together from sub-consensus variants detected at previous time points.
One of the eleven mutations that arose together was an additional and novel point mutation in the S codon 484, which changed the amino acid residue to threonine (T). This substitution remained in sequencing timepoints 11 months post-diagnosis.
In the next two months, the frequency of E484T and 10 other concomitant mutations fell far below consensus. Finally, after 13 months post-diagnosis, S codon 484 reverted to E484A.
The E484T variant remained unique to the individual described in the study and did not transmit further. Fortunately, public health officials were able to successfully contain its spread by quarantining this individual for almost 16-months at home.
Despite limited data from the county where this individual lived, surveillance sequencing suggested the possibility that the mutations that arose and disappeared had an associated fitness cost. Therefore, the authors recommended continuing surveillance programs to identify prolonged infections and characterize such viral adaptations to gain in-depth insights into the future SARS-CoV-2 evolution.
The current study describes the first case of infection by the new SARS-CoV-2 E484T variant, thereby highlighting the potential role of immunocompromised individuals in providing an environment conducive to the generation and propagation of novel variants.
In fact, as of February 2022, S E484T had not been documented in any other SARS-CoV-2 samples. Thus, the current study highlights the need for frequent RT-PCR testing, SARS-CoV-2 genome sequencing, and proactive treatment for prolonged SARS-CoV-2 infections occurring in immunocompromised individuals.
The E484T variant arose after bamlanivumab monotherapy; however, due to the lack of sequence data from the patient’s earlier infection, the researchers could not conclusively determine whether the E484A variant arose de novo in this individual or they were infected with a lineage harboring E484A. Thus, this case also highlights the potential value of archiving test-positive specimens from immunocompromised individuals.
The authors emphasize the need for a national-level or worldwide registry to help researchers examine cases of prolonged SARS-CoV-2 infection in higher numbers at one clinical site. Additionally, they recommended that the United States government should offer support to millions of immunocompromised individuals who are unable to continue work or afford healthcare.
medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.
Original Source: news-medical.net
Genetic bottlenecks could impact Wyoming toads’ ability to respond to new pathogens
A new study from North Carolina State University examines immune system diversity in the critically endangered Wyoming toad and finds that genetic bottlenecks could impact a species’ ability to respond to new pathogens. The findings could inform captive breeding strategies for endangered animal populations.
The Wyoming toad, Anaxyrus baxteri, suffered a severe population decline throughout the latter part of the 20th century due to factors including habitat destruction and fungal infection. The toad was brought into a captive breeding program in the 1990s in order to save the species. Scientists estimate a current wild population of only 400 to 1,500 animals, meaning that the toad is considered critically endangered.
Population reduction in this species created a genetic bottleneck to begin with, meaning the level of genetic diversity is already very small. This is the first study to look specifically at genetic diversity in the immune systems of these toads and how it could impact them as a population.”
Jeff Yoder, professor of comparative immunology at NC State and co-corresponding author of paper
Yoder, with co-corresponding author Alex Dornburg of the University of North Carolina at Charlotte, performed RNA sequencing on immune tissues from three healthy, retired Wyoming toad breeders. Study co-author Michael Stoskopf, who was on the Wyoming Toad Recovery Implementation Team established in 2008, obtained the samples.
“We were focused specifically on sequences encoding toll-like receptors – TLRs – and the proteins of the major histocompatibility complex, or MHC, expressed in these tissues,” says Kara Carlson, first author of the study and current Ph.D. candidate at NC State. “These sets of genes are major components of the immune system.”
TLRs are the first responders of the immune system, and are similar, or well-conserved, between species. The MHC, on the other hand, is a large and diverse group of genes that varies between species and individuals. It can determine why one group is more resistant to a particular pathogen than another.
“MHC genes are some of the most rapidly evolving sequences in the genome,” Carlson says. “So in a healthy population there’s a lot of variety that gets passed along to descendants, enabling the species at large to adapt to different pathogens. However, if disease survivors do so because of their MHC, then that group would have a similar MHC.
“The Wyoming toads that were brought into captivity to save the species were all able to resist the fungus that had decimated the population, but that could mean that their immune diversity is reduced.”
The researchers compared the TLR and MHC of the three Wyoming toads to each other, as well as to samples from a common toad and a cane toad. Both the common toad and the cane toad showed more MHC diversity than the Wyoming toad, even though the cane toad underwent a similar genetic bottleneck.
“The small sample size in this study – which was unavoidable due to the endangered status of the toad – nevertheless lays an important framework for conservation,” Carlson says.
“Amphibians in general don’t have as many genomic resources as other organisms,” Yoder says. “And captive breeding from a small population further decreases genetic diversity. But while these toads may be better protected against the fungal infection that nearly wiped them out, they may not be equipped to deal with new pathogens down the road.”
“While we weren’t necessarily surprised by the lack of immunogenic diversity in the Wyoming toad, it does spark an important question,” Dornburg says. “How equipped are other species of conservation concern for a battle with an emergent pathogen?”
“By understanding the genetic diversity of the immune system we can inform captive breeding to increase the chance of a species to resist disease in the wild,” Yoder adds. “Studies like this one are invaluable for captive breeding practices going forward.”
Carlson, K.B., et al. (2022) Transcriptome annotation reveals minimal immunogenetic diversity among Wyoming toads, Anaxyrus baxteri. Conservation Genetics. doi.org/10.1007/s10592-022-01444-8.
Original Post: news-medical.net
Video conferencing hinders creativity
In-person teamwork has now transformed into virtual collaboration due to the COVID-19 pandemic. But does this affect innovation and creativity?
An interesting study on virtual communication led by Dr. Melanie S. Brucks from Columbia University and Prof. Jonathan Levav from Stanford University is published in the journal Nature. The study examines whether videoconferencing affects creative idea generation.
Study: Virtual communication curbs creative idea generation. Image Credit: Andrey_Popov / Shutterstock
Communication and collaboration
Collaboration is essential for several workplace tasks. It leads to innovation and idea generation. Historically, these collaborations have been in-person and required sharing of the same physical space. The use of traditional communication technologies like letters, emails, and phone calls hinder the smooth exchange of information and limits collaboration.
Now, due to advances in audio-visual technology, face-to-face interaction is possible via videoconferencing, allowing virtual collaboration. Videoconferencing has replaced in-person interactions due to pandemic-driven social distancing. Video interaction and in-person interaction allow communication of the same information.
While videoconferencing replacing in-person interaction has been beneficial in the social scenario, does it come with a cost in the workplace scenario? For example, does it affect collaborative idea generation?
The investigators performed a Laboratory experiment and a field experiment to test the difference between in-person interaction and videoconferencing in collaborative idea generation. First, they recruited participants and divided them into pairs: half of the pairs were assigned to an in-person setting, and the rest were assigned to a virtual setting.
A total of 602 participants were recruited for the laboratory experiment and divided into pairs. The participants were in separate rooms in the virtual setting and communicated through videoconferencing. The pairs were allotted five minutes to generate creative uses for a frisbee (150 pairs) or bubble wrap (151 pairs) and then one minute to select their most innovative idea.
The pairs were evaluated by counting the number of creative ideas and ideas they generated. The virtual pairs generated significantly fewer total and creative ideas compared to in-person pairs.
So, virtual collaboration hampered creative ideas. This could be because the virtual space narrows the visual scope, which in turn narrows the cognitive scope. To assess the visual focus, two methods were used. Firstly, the participants had to recollect the individual props in the room and point them on a worksheet. Secondly, the participants’ eye gaze was recorded during the experiment.
The virtual pairs narrowed their focus to the screen. Compared to in-person pairs, they spent significantly more time looking directly at their partner and less time looking at the surrounding room, and remembered significantly fewer props in the surrounding room.
As a consequence, the virtual medium narrowed the visual focus and inhibited the generation of ideas.
However, these results are in the context of a controlled laboratory setting.
The experiment was repeated in ‘the field’ under actual work conditions within a large multinational telecommunications company to see if these results could be extrapolated to the real world. The field experiment was conducted in five country sites – in Europe, the Middle East, and South Asia. In this setting, the participants knew their partners and used video conferencing regularly for work. Moreover, it included domain experts highly invested in the outcome of the collaboration.
A total of 1,490 engineers were recruited to participate in an ideation workshop and randomly divided into pairs. The pairs were allotted an hour to generate product ideas and submit one idea as future product innovation for the company.
The engineer pairs who worked on the task virtually generated fewer total ideas and creative ideas than in-person pairs at all five sites.
However, the decision quality was not affected by virtual collaboration. The in-person pairs generated a significantly higher top-scoring idea, but the selected idea did not significantly differ in quality between the virtual pairs and in-person pairs.
Other reasons for reduced creativity
The could be other reasons why virtual collaboration negatively affected idea generation. Therefore, the investigators explored the alternative explanations.
Since the in-person collaborators generated more total and creative ideas than the virtual collaborators, they could generate additional ideas similar to each other. However, upon semantic analysis, it was observed that they generated diverse and disconnected ideas.
Feelings of connection and trust
Studies have shown that feelings of connection and trust can foster team creativity. The virtual pairs may have reduced feelings of connection and trust toward their partner.
However, when assessed for subjective feelings of closeness, verbal and non-verbal behaviors, and mimicry, the virtual pairs were similar to in-person pairs in the laboratory experiment.
Thus, virtual and in-person interactions are very similar in terms of social connection or social behavior.
Usually, there is a lack of coordination in a conversation in virtual interactions due to the absence of eye contact. However, it could not wholly explain the effect of virtual interaction on idea generation.
This study also assessed the effect of interpersonal processes on idea generation. Interpersonal processes fear of evaluation, dominance, social facilitation, social loafing, social sensitivity, perceptions of performance, and production blocking were affected in virtual collaborations and these, in turn, affected idea generation.
Implications of the study
This study supports previous research suggesting that pairs perform better than large groups, both in-person and online. Therefore, this study recommends ideation in pairs and in person. Also, this study suggests that larger videoconferencing screens would not impact idea generation.
In-person collaborations offer a cognitive advantage. Now several workplaces are moving towards a hybrid setup. This study indicates that the creative idea generation should be reserved for in-person meetings.
Original Post: news-medical.net
Gum Health Day 2022 calls for prevention, early detection, and effective treatment of gum diseases
“Treat your gums” is the slogan for Gum Health Day 2022, a worldwide awareness campaign organized by the European Federation of Periodontology (EFP). The event aims to inform the public of the detrimental effects of gum diseases – gingivitis, periodontitis, peri-implant mucositis, and peri-implantitis – on both oral and overall health. The campaign calls for the prevention, early detection, and – where necessary – effective treatment of gum diseases.
Although still poorly acknowledged by the public, gum diseases are chronic inflammatory conditions affecting a high proportion of adults worldwide, causing tooth loss and other problems in the mouth. Crucially, gum diseases are also linked to major systemic health issues including diabetes mellitus, cardiovascular diseases, chronic kidney disease, adverse pregnancy outcomes, rheumatoid arthritis, Alzheimer’s disease, erectile dysfunction, certain forms of cancer, and more severe Covid-19 outcomes. This means that gum diseases and their prevention and treatment are of major importance not only for oral health, but also for the whole body.
This year’s campaign focuses heavily on the treatment part – we know that millions of people suffer from gum diseases that can be treated effectively. ‘Treat your gums’ calls for this treatment – with all the documented positive effects for the mouth and whole body – to actually happen.”
Moritz Kebschull, coordinator of Gum Health Day 2022
That is why the hashtag for the campaign is #TreatYourGums, and why the recent EFP-produced clinical practice guidelines on the treatment of periodontitis are a major part of the Gum Health Day 2022 initiative.
“The new EFP-produced clinical practice guidelines on the treatment of all four stages of periodontitis are a crucial development, as they are the first high-quality international guidelines to outline a structured and easily implemented pathway for the efficient and effective treatment of gum disease,” Prof. Kebschull says. “In a nutshell, gum disease treatment that works!”
He adds: “It is important to underline that gum disease is one of the most widespread chronic diseases in the worldwide adult population, and that it is usually painless, so its early detection and successful treatment depends heavily on how fast the patient takes action.”
A major innovation of Gum Health Day 2022 is an EFP-designed “customized content generator”, a feature that allows the federation’s 37 affiliated national societies of periodontology, their individual members – as well as practices, hospitals, and members of the public – to customise their own Gum Health Day 2022 materials, based on a series of graphic templates and catchphrases.
In the framework of Gum Health Day 2022, the EFP encourages periodontists, dentists, researchers, and other health-related professionals to sign and disseminate the EFP Manifesto: Perio and General Health, an international call to action for the prevention, early detection, and treatment of gum disease. Individuals and organisations are invited to endorse it and join the 1,200+ professionals, dental practices, companies, and universities that have so far supported it.
The European Federation of Periodontology (EFP, ww.efp.org) is a non-profit organization dedicated to promoting awareness of periodontal science and the importance of gum health. Its guiding vision is “periodontal health for a better life.”
Founded in 1991, the EFP is a federation of 37 national periodontal societies that represents more than 16,000 periodontists, dentists, researchers, and oral-health professionals from Europe and around the world. It supports evidence-based science in periodontal and oral health, and it promotes events and campaigns aimed at both professionals and the public.
The EFP organizes EuroPerio, the world’s leading congress in periodontology and implant dentistry, as well as other important professional and expert events such as Perio Master Clinic and Perio Workshop. The annual Gum Health Day on May 12, organized by the EFP and its member societies, brings key messages on gum health to millions of people across the world.
The EFP also organizes workshops and outreach campaigns with its partners: projects to date have covered the relationship between periodontal disease and diabetes, cardiovascular disease, and caries, as well as women’s oral health during pregnancy.
The EFP’s Journal of Clinical Periodontology is the most authoritative scientific publication in this field. The federation also publishes JCP Digest, a monthly digest of research, and the Perio Insight magazine, which features experts’ views and debates.
The EFP’s work in education is also highly significant, notably its accreditation programme for postgraduate education in periodontology and implant dentistry.
The EFP has no professional or commercial agenda.
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