The high infectivity of the SARS-CoV-2 Omicron variant is associated with an exclusive S477N spike receptor-binding domain mutation (preprint)

The spike glycoprotein receptor-binding domain (RBD) of SARS-CoV-2 facilitates viral binding to the ACE2 receptor and mediates viral infectivity. The Delta and Omicron variants of concern are the most infectious strains, presenting mutated amino acid residues in their spike RBD. The Omicron variant quickly dominated the COVID-19 pandemic, indicating its greater spreadability. Omicron spreading might be associated with mutational substitutions at spike RBD residues. We employed in silico molecular dynamics (MD) simulation of the spike RBD-ACE2 interaction to compare the impact of specific mutations of the Delta and Omicron variants. The MD of the spike-ACE2 interaction showed the following: i) the amino acid profile involved in the spike-ACE2 interaction differs between Delta and Omicron; ii) the Omicron variant establishes several additional interactions, highlighting the spike RBD (S477), which is a flexible mutational residue. Since the S477N mutation is exclusive to Omicron, which may initiate binding with ACE2, the increased infectivity of Omicron might be associated not only with a mutated RBD but also with unmutated (e.g., G476 and L492) residues, initiating binding due to the influence of the N477 mutation. Compared to previous variants, Omicron N477 residue represents a novelty within the spike-ACE2 interaction dynamics interface.

DIVERSIDADE ÉTNICA DE CANDIDATOS A DOAÇÃO DE MEDULA ÓSSEA E OS DESAFIOS PÓS PANDEMIA DA COVID-19

Introdução: O transplante alogênico de células-tronco hematopoiéticas (TCTH) permite a substituição de células-tronco hematopoiéticas (HSCs) doentes, ou deficitárias, por HSCs de um doador saudável. Aproximadamente 70% dos pacientes que necessitam de um transplante de células-tronco hematopoiéticas não possuem doadores compatíveis na família, necessitando de doadores voluntários não conhecidos. O sucesso do TCTH é condicionado à compatibilidade entre genes do tipo HLA. No Brasil, país com alta taxa de miscigenação, a probabilidade de se encontrar um doador compatível fora do núcleo familiar, é de 64% na fase final do processo. Sabendo-se disso e com a intenção de reunir informações sobre os doadores voluntários de medula óssea para transplante, foi criado no Brasil, o Registro Nacional de Doadores de Medula Óssea (REDOME), que reúne mais de 5,2 milhões de doadores cadastrados. Objetivos: Mapear a diversidade étnica dos candidatos a doação de medula óssea cadastrados no sistema REDOME e elucidar os desafios que o TCTH enfrenta com a pandemia da Covid-19. Materiais e métodos: Levantamento de dados previamente disponibilizados no Registro Nacional de Doadores de Medula Óssea, considerando, em números absolutos e percentuais, o perfil étnico e demográfico de candidatos a doação de medula óssea no período de 2013 a 2020, no Brasil, além de abordar a importância da manutenção do cadastro de doadores e o enfrentamento da Covid-19 no transplante de células-tronco hematopoiéticas. Resultados: Até o ano de 2020, totalizaram-se 5.304.714 doadores cadastrados no REDOME, um aumento de 163,4%, quando comparado ao ano de 2013, nos cadastros de doadores voluntários, o que representa uma média anual de 280 mil novos registros. Quando observado a distribuição de doadores e receptores por regiões do Brasil, nota-se que a maior demanda provém da região Sudeste (56%) e não consegue ser suprida pela concentração de 44% de doadores na mesma região, diferentemente da região Norte, que compõe 5% dos receptores, sendo a região com menor centralização, e 7% dos doadores. Ao observar a etnicidade dos doadores, 54,21% se autodeclaram brancos, já os receptores ocupam uma porcentagem de 65,09%. Discussão: A partir dos resultados, é evidenciado que, apesar de um número razoável de doadores já exista, as campanhas de captação de novos doadores devem ser focadas em doadores geneticamente diferenciados e na manutenção de dados dos já cadastrados. No presente cenário brasileiro, o TCTH enfrenta um novo desafio: a pandemia da Covid-19, doença causada pelo novo coronavírus (SARS-Cov-2), desencadeou uma preocupação mundial quanto à redução do número de doadores de sangue e manutenção dos estoques de sangue, principalmente devido às medidas de distanciamento social recomendadas pela OMS. Dentre as estratégias observadas para reorganizar a rede assistencial visando a absorver o aumento da demanda hospitalar destacaram-se: a mudança da rotina hospitalar, com adiamento de procedimentos e internações eletivas e mudança de perfil, para a realocação e destinação exclusiva de leitos para internação de pacientes com Covid-19, evidenciado através da redução de 21,38% dos novos cadastros. Conclusão: o Brasil não apresenta um cenário favorável aos pacientes que esperam pelo procedimento, sendo crucial a mobilização dos diversos setores de saúde, ainda sendo perceptível como a pandemia da Covid-19 afetou o cadastramento de novos voluntários, assim como a realização dos procedimentos.

Anti-COVID-19 vaccine late hypersensitivity reaction

Background: First approved anti-COVID vaccines brought a new experience of hypersensitivity reactions into clinical practice. This experience and knowledge of mechanisms are important for further safer and wider use of these immunizations. Methods: Clinical and laboratory data collected in immunoallergology outpatient evaluation and consultation of informatic process. Written consent was obtained. Results: We report a case of a 33-year-old woman, a laboratory worker, who received the first dose of mRNA-based anti-COVID-19 vaccine. After 48-72h she presented with extensive generalized urticaria lesions and pruritus. She was admitted to the emergency department, treated with endovenous corticosteroid and antihistaminic, attenuating skin lesions. However, 12-24h later, urticaria exacerbated, with labial and bilateral ear swelling. She was medicated with oral prednisolone, gradually resolving symptoms. She had no concomitant alcohol/ drug consumption nor practiced physical exercise. She had antecedents of persistent allergic rhinitis and allergic bronchial asthma in the first step of treatment. She had no prior history of drug allergy nor adverse reactions to vaccines. Skin prick tests performed with commercial extracts of aeroallergens were positive for D. pteronyssinus, D. farinae, lepidoglyphus, olive tree pollen, grass pollen, and cat and dog dander. Skin prick test with latex was negative. Basal tryptase was 6.4 and total IgE 154.0 UI/mL. Spirometry was normal at basal condition. Prick test with anti-COVID-19 vaccine was negative. Intradermal test with 1/100 and 1/10 dilutions of anti-COVID-19 vaccine was also negative at 20-30 minutes. However, after 4h she showed hyperemia and swelling of about 7-8cm, localized at the place of both dilutions of intradermal test vaccine administration. PATCH tests performed with anti-COVID-19 vaccine were negative at 48h and 72h readings. She was diagnosed with anti-COVID-19 vaccine late hypersensitivity and, therefore, was not able to take the second dose. Discussion: We report a clinical case of late hypersensitivity to mRNA-based anti-COVID-19 vaccine in a patient without prior history of drug allergy. The reaction was documented with positive intradermal tests performed with 1/100 and 1/10 vaccine dilutions. According to EAACI indications, she did not receive the second dose of the vaccine. Extracts of vaccine components will help to understand adverse reactions and choosing an alternative vaccine, when available.

Web-based tools applied to therapy and counseling during the COVID-19 pandemic

IntroductionWeb-based tools allowed the provision of psychological counseling and therapy at-distance during the COVID-19 lockdown. Nevertheless, psychologists’ attitudes towards the adoption of these tools and its impact in their professional practices need to be further explored.ObjectivesThe objective was to study the use of web-based tools on psychological practices before and during COVID-19 lockdown, trying to identify changes on psychologists’ professional practices related to the pandemic, as well as to explore factors that could have affected such changes.MethodsOne-hundred and eight psychologists filled-in an online survey, developed for the purposes of this study, during mandatory lockdown. The study was disseminated by mailing list, social networks, and by the Portuguese Psychologists Association.ResultsThe results have shown that psychologists kept providing their services during lockdown thanks to the adoption of web-based tools. Although psychologists have recognized that additional precautions were needed for at-distance practice in comparison to in-person interventions, the experience of using IC technologies in clinical practice was described as positive, ensuring clients’ adherence with positive results. Additionally, despite psychological services were maintained on a larger scale by psychologists with more years of experience, professionals with average experience stated more favorable attitudes towards the use of web-based tools in counseling and therapy.ConclusionsAlthough the implementation of ICT based practice was enforced by current circumstances, the experience that psychologists gathered and shared during the lockdown can guide future professional practice, improving and fostering the replication of best practices at distance.

The high infectivity of SARS-CoV-2 B.1.1.7 is associated with increased interaction force between Spike-ACE2 caused by the viral N501Y mutation (preprint)

The Spike glycoprotein receptor-binding domain (RBD) of SARS-CoV-2 mediates the viral particle's binding to the angiotensin-converting enzyme 2 (ACE2) receptor on the surface of human cells. Therefore, Spike-ACE2 interaction is a crucial determining factor for viral infectivity. A new phylogenetic group of SARS-CoV-2 (lineage B.1.1.7) has been recently identified in the COVID-19 Genomics UK Consortium dataset, which features an amino acid substitution in the Spike RBD (N501Y mutation). Infections with the SARS-CoV-2 lineage B.1.1.7 have been overgrowing in recent weeks in the United Kingdom, indicating an even greater spread capacity than that seen with previous strains of the novel coronavirus. We hypothesized that this rapid spreading/infectivity of the B.1.1.7 lineage might be due to changes in the interaction force between the mutant Spike RBD and ACE2. This study employed in silico methods involving mutagenesis (N501Y mutation) and interface analysis focusing on the Spike RDB-ACE2 interaction. The results showed that the SARS-CoV-2 N501Y mutant (lineage B.1.1.7) establishes a more significant number of interactions relating to the mutant residue Y501 (Spike RDB) with residues Y41 and K353 (ACE2). This finding shows that the increased infectivity of SARS-CoV-2 lineage B.1.1.7 is associated with the interaction force between the Spike RBD Y501 mutant residue with the ACE2 receptor, which in this strain is increased.

Cooking skills during the Covid-19 pandemic

This article aims to present reflections on cooking skills in times of the coronavirus disease 2019 pandemic. The current period of uncertainty and isolation heightens food insecurity issues, influencing food choice, purchase, and preparation. Social media and networks are sources of entertainment and learning, with vast resources for cooking skills, which can stimulate home cooking and strengthen family ties. Research has evidenced the positive relationship between cooking and diet quality, an important factor for groups at increased risk of severe illness from Covid-19. For some individuals, cooking may be a strategy to reduce anxiety and stress associated with the pandemic. However, the Brazilian reality is marked by inequalities in income and access to food. Thus, more vulnerable populations may not have the same relationship with cooking. Public policies should focus on food and nutrition programs and actions for the development of cooking skills as a means to promote healthy eating and encourage self-care.