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2022 ◽  
Author(s):  
Lauren B. Rodda ◽  
Peter A. Morawski ◽  
Kurt B. Pruner ◽  
Mitchell L. Fahning ◽  
Christian A. Howard ◽  
...  

Immune memory is tailored by cues that lymphocytes perceive during priming. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic created a situation in which nascent memory could be tracked through additional antigen exposures. Both SARS-CoV-2 infection and vaccination induce multifaceted, functional immune memory, but together they engender improved protection from disease, termed hybrid immunity. We therefore investigated how vaccine-induced memory is shaped by previous infection. We found that following vaccination, previously infected individuals generated more SARS-CoV-2 RBD-specific memory B cells and variant-neutralizing antibodies and a distinct population of IFN-𝛾 and IL-10-expressing memory SARS-CoV-2 spike-specific CD4+ T cells than previously naive individuals. While additional vaccination could increase humoral memory, it did not recapitulate the distinct CD4+ T cell cytokine profile in previously naive individuals. Thus, imprinted features of SARS-CoV-2-specific memory lymphocytes define hybrid immunity.


2022 ◽  
Author(s):  
Wael Hamed Roshdy ◽  
Mohamed K Khalifa ◽  
James Emmanuel San ◽  
Houriiyah Tegally ◽  
Eduan Wilkinson ◽  
...  

COVID-19 was first diagnosed in Egypt on 14 February 2020. By the end of November 2021, over 333,840 cases and 18,832 deaths had been reported. As part of national genomic surveillance, 1,027 SARS-CoV-2 near whole-genomes had been generated and published by the end of May 2021. Here we describe the genomic epidemiology of SARS-CoV-2 in Egypt over this period using a subset of 976 high-quality Egyptian genomes analysed together with a representative set of global sequences within a phylogenetic framework. We show that a single lineage, C.36, introduced early in the pandemic was responsible for most cases in Egypt. Furthermore, we show that to remain dominant in the face of mounting immunity from previous infection and vaccination, this lineage evolved into various sub-lineages acquiring several mutations known to confer adaptive advantage and pathogenic properties. These results highlight the value of continuous genomic surveillance in regions where VOCs are not predominant and enforcement of public health measures to prevent expansion of existing lineages.


Author(s):  
Poonam Ghodki ◽  
Neha Panse ◽  
Shalini Sardesai

Background: Data regarding sudden surge of mucormycosis cases with COVID-19 outbreak and its impact on anaesthesia management are lacking. This retrospective study was designed to analyze the number and characteristics of patients posted for mucormycosis surgery in COVID19 pandemic while emphasizing upon the anaesthesia concerns. Methods: Data was collected from all patients who were admitted with mucormycosis in our institute from the year 2020 onwards. Further analysis of patients who were surgically treated was carried out in terms of demographic characteristics, association with COVID19 and perioperative course of mucormycosis and anaesthetic management. All statistical analyses were performed with the Statistical package for social sciences (SPSS) version 25·0 software. Results: We report an incidence of 30 operated patients of the average age 52.60 years with mucormycosis from August 2020 to May 2021. Diabetes as a comorbidity was common (86.90%).  Previous infection with COVID-19 was observed in 29 (96.60%) out of which 80% patients had residual pulmonary involvement. Concomitant medical therapy with Amphotericin B was received by 90% patients and subsequently 70% had deranged renal profile. While 20 % patients had compromised airway, 60 % required blood transfusion and 76.6% patients were electively ventilated while 1 patient (3.3%) succumbed amounting to a survival rate of 96.6%. Conclusion: To conclude elderly male diabetic patients with history of COVID19 infection is the most vulnerable population for developing mucormycosis. Airway management, glycemic control, concomitant Amphotericin B therapy and intraoperative bleeding are the major challenges for anaesthesiologist along with an element of post Covid respiratory compromise.


2022 ◽  
pp. 439-503

This chapter includes corneal surgeries performed in the center such as corneal transplantation (PK, DALK, DSAEK, DMEK) with all possible complications: graft rejections, recurrence of previous diseases, reactivation of previous infection, and other rare complications. Photos of conjunctival limbal autotransplantation, Boston type 1 keratoprosthesis surgery, and corneal tattooing are included as well. Some interesting cases are discussed with management. Several possible complications after excimer laser procedures are also presented.


Vaccines ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 64
Author(s):  
Ariel Israel ◽  
Yotam Shenhar ◽  
Ilan Green ◽  
Eugene Merzon ◽  
Avivit Golan-Cohen ◽  
...  

Immune protection following either vaccination or infection with SARS-CoV-2 is thought to decrease over time. We designed a retrospective study, conducted at Leumit Health Services in Israel, to determine the kinetics of SARS-CoV-2 IgG antibodies following administration of two doses of BNT162b2 vaccine, or SARS-CoV-2 infection in unvaccinated individuals. Antibody titers were measured between 31 January 2021, and 31 July 2021 in two mutually exclusive groups: (i) vaccinated individuals who received two doses of BNT162b2 vaccine and had no history of previous infection with COVID-19 and (ii) SARS-CoV-2 convalescents who had not received the vaccine. A total of 2653 individuals fully vaccinated by two doses of vaccine during the study period and 4361 convalescent patients were included. Higher SARS-CoV-2 IgG antibody titers were observed in vaccinated individuals (median 1581 AU/mL IQR [533.8–5644.6]) after the second vaccination than in convalescent individuals (median 355.3 AU/mL IQR [141.2–998.7]; p < 0.001). In vaccinated subjects, antibody titers decreased by up to 38% each subsequent month while in convalescents they decreased by less than 5% per month. Six months after BNT162b2 vaccination 16.1% subjects had antibody levels below the seropositivity threshold of <50 AU/mL, while only 10.8% of convalescent patients were below <50 AU/mL threshold after 9 months from SARS-CoV-2 infection. This study demonstrates individuals who received the Pfizer-BioNTech mRNA vaccine have different kinetics of antibody levels compared to patients who had been infected with the SARS-CoV-2 virus, with higher initial levels but a much faster exponential decrease in the first group.


2021 ◽  
Author(s):  
Demi ME Pagen ◽  
Stephanie Brinkhues ◽  
Nicole HTM Dukers-Muijrers ◽  
Casper DJ den Heijer ◽  
Noortje Bouwmeester-Vincken ◽  
...  

Abstract BackgroundThe availability of valid SARS-CoV-2 serological tests overcome the problem of underestimated cumulative COVID-19 cases during the first months of the pandemic in The Netherlands. This enabled us to study a wide variety of demographic, behavioural and social exposure factors associated with seropositivity during the first eight months of the pandemic in Limburg, The Netherlands. MethodsSARS-CoV-2 point-seroprevalence was determined cross-sectionally to indicate previous infection in a convenience sample of 10,000 inhabitants of the study province. Possible exposure factors were mapped by means of an extensive questionnaire. Associated exposure factors were determined using uni- and multivariable logistic regression models.ResultsSeropositivity was established in 19.5% (n=1,948) of the 10,001 participants (on average 49 years old (SD=15; range 18-90 years), majority women (n=5,829; 58.3%). Exposure factors associated with seropositivity included current education, working in healthcare and not working from home, and being a member of three or four associations or clubs. Specifically for February-March 2020, visiting an après-ski bar during winter sports in Austria, travelling to Spain, celebrating carnival, and participating in a singing activity or ball sport were associated with seropositivity. ConclusionsOur results confirm that relevant COVID-19 exposure factors generally reflected circumstances where social distancing was impossible, and the number and duration of contacts was high, in particular for indoor activities.


2021 ◽  
Author(s):  
Roxane Dumont ◽  
Mayssam Nehme ◽  
Elsa Lorthe ◽  
Carlos De Mestral ◽  
Viviane Richard ◽  
...  

Background: It is now established that a significant proportion of adults experience persistent symptoms after SARS-CoV-2 infection. However, evidence for children and adolescents is still inconclusive. In this population-based study, we examine the proportion of children and adolescents reporting persistent symptoms after SARS-CoV-2 infection, as assessed by serological status, and compare this to a seronegative control group. Methods: We conducted a serosurvey in June-July 2021, recruiting 660 children and adolescents from 391 households selected randomly from the Geneva population. We tested participants for anti-SARS-CoV-2 antibodies targeting the nucleocapsid (N) protein to determine previous infection. A parent filled a questionnaire including questions on COVID-19-related symptoms lasting at least 2 weeks. Findings: Among children seropositive for anti-SARS-CoV-2 antibodies, the sex- and age-adjusted prevalence of symptoms lasting longer than two weeks was 18.3%, compared to 11.1% among seronegative children (prevalence difference (ΔaPrev)=7.2%, 95%CI:1.5-13.0). Main symptoms declared among seropositive children were fatigue (11.5%) and headache (11.1%). For 8.6% (aPrev, 95%CI: 4.7-12.5) of seropositives, these symptoms were declared to be highly limiting of daily activities. Adolescents aged 12-17 years had a higher adjusted prevalence of persistent symptoms (aPrev=29.1%, 95%CI:19.4-38.7) than younger children. Comparing seropositive and seronegative adolescents, the estimated prevalence of symptoms lasting over four weeks is 4.4% (ΔaPrev, 95%CI:-3.8-13.6). Interpretation: A significant proportion of children aged 12 to 17 years had symptoms lasting over two weeks after SARS-CoV-2 infection, with an estimated prevalence of symptoms lasting over 4 weeks of 4.4% in this age group. This represents a large number of adolescents in absolute terms, and should raise concern in the context of unknown long-term evolution of symptoms. Younger children appear to experience long-lasting symptoms less frequently, as no difference was observed between the seropositive and seronegative sample. Further studies with larger samples sizes are needed.


Vaccines ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 9
Author(s):  
Marek Petráš ◽  
Ivana Králová Lesná ◽  
Livia Večeřová ◽  
Elka Nyčová ◽  
Jana Malinová ◽  
...  

Continuous assessment of the effectiveness of approved COVID-19 vaccines is crucial to gain an insight into the longer-term impact on health outcomes, and eventually boosting public confidence. For this reason, we conducted a multicenter, retrospective cohort study using data on infection and vaccination rates among employees of three Prague hospitals in the period between 27 December 2020 and 31 August 2021. The post-vaccination and post-infection protectiveness were assessed in a total of 11,443 hospital workers who were followed up for more than 14 days either after their Comirnaty vaccination or study enrolment, depending on their previous SARS-CoV-2 infection. The effectiveness of full vaccination against any SARS-CoV-2 infection achieved 88.3% (83.2–91.8%) over the eight months of follow-up, a figure not much different from the 92.5% (76.5–97.6%) level of protection built by a previous infection. Despite this, the post-vaccination level of protection declined to about 65% between June and August. No case of breakthrough infection was registered among hospital workers having received one or two vaccine doses more than three months after previous infection. The eight-month effectiveness of the Comirnaty vaccine exhibited a declining trend requiring a new booster dose. The need for vaccination in the previously infected employees was not demonstrated conclusively in this study.


2021 ◽  
Author(s):  
Abdullah Muhammad Syed ◽  
Alison Ciling ◽  
Mir M. Khalid ◽  
Bharath Sreekumar ◽  
G. Renuka Kumar ◽  
...  

The Omicron SARS-CoV-2 virus contains extensive sequence changes relative to the earlier arising B.1, B.1.1 and Delta SARS-CoV-2 variants that have unknown effects on viral infectivity and response to existing vaccines. Using SARS-CoV-2 virus-like particles (SC2-VLPs), we examined mutations in all four structural proteins and found that Omicron showed increased infectivity relative to B.1, B.1.1 and similar to Delta, a property conferred by S and N protein mutations. Thirty-eight antisera samples from individuals vaccinated with tozinameran (Pfizer/BioNTech), elasomeran (Moderna), Johnson & Johnson vaccines and convalescent sera from unvaccinated COVID-19 survivors had moderately to dramatically reduced efficacy to prevent cell transduction by VLPs containing the Omicron mutations. The Pfizer/BioNTech and Moderna vaccine antisera showed strong neutralizing activity against VLPs possessing the ancestral spike protein (B.1, B.1.1), with 3-fold reduced efficacy against Delta and 15-fold lower neutralization against Omicron VLPs. Johnson & Johnson antisera showed minimal neutralization of any of the VLPs tested. Furthermore, the monoclonal antibody therapeutics Casirivimab and Imdevimab had robust neutralization activity against B.1, B.1.1 or Delta VLPs but no detectable neutralization of Omicron VLPs. Our results suggest that Omicron is at least as efficient at assembly and cell entry as Delta, and the antibody response triggered by existing vaccines or previous infection, at least prior to boost, will have limited ability to neutralize Omicron. In addition, some currently available monoclonal antibodies will not be useful in treating Omicron-infected patients.


2021 ◽  
Author(s):  
Maria Ganczak ◽  
Marcin Korzeń ◽  
Ewa Sobieraj ◽  
Jakub Goławski ◽  
Oskar Pasek ◽  
...  

Abstract Background Polish teachers, as the priority group, were offered the ChAdOx1-S vaccine since February 2021. The objective was to investigate safety, tolerability and immunogenicity of this vaccine following two vaccine doses. Methods Teachers were invited for serological testing ≥8 weeks after second vaccination. Quantitative post-vaccination anti-spike antibody responses were measured using the Abbott SARS-CoV-2 IgG II Quant assay (detection threshold: ≥7.1 BAU/ml). Multivariable logistic regression methods were used to identify predictors of immunogenicity. Results Of 192 teachers, mean age 50.5±8.3 years, 83.9% were females. Median (range) dosing interval was 50 (14-95) days; median interval between the second dose and immunogenicity test was 69 days (range: 57–111). More than a half of teachers (58.3%) reported they would change the product for another (mostly mRNA) vaccine if there was such an opportunity. Adverse reactions after receiving the vaccine (either the first or the second dose) were reported by 79.2% teachers, more frequently after the first dose (84.9%), and were similar in nature to those previously reported: feeling feverish (44.8%), headache (41.7%), malaise, chills (both: 38.0%), injection-site tenderness (37.5%) and pain (32.3%). Less males than females (54.8% vs 80.1%) and older (aged ≥50 years) than younger teachers (65.7% vs 90.4%) reported side effects (p<0.002; p<0.0001, respectively). By ≥8 weeks after the boost dose, all teachers had neutralizing antibody responses. The median (range) anti-spike IgG reading was 525.0 BAU/mL (20.6-5680.0 BAU/mL); 1008.02 (115.3–5680.0) BAU/mL in teachers with evidence of prior infection and 381.42 BAU/mL (20.6–3108.8) in those without (p=0.001). Previous infection with SARS-CoV-2 and longer dose interval were both positive predictors of higher immunologic response (p<0.0001; p=0.01, respectively), with no evidence of differences by age, gender, BMI, smoking or comorbidities. Conclusions The results demonstrated good safety, tolerability and immunogenicity of the ChAdOx1-S vaccine. Immunization led to detectable anti-spike antibodies in all teachers. Our study justifies the longer dose interval as an important factor to enhance higher antibody response. Findings suggest that in immunocompetent vaccine recipients with an evidence of previous infection a delay regarding the second dose could be considered when careful management in the use of vaccine resources is needed.


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