scholarly journals Naturally-acquired immunity in Syrian Golden Hamsters provides protection from re-exposure to emerging heterosubtypic SARS-CoV-2 variants B.1.1.7 and B.1.351

2021 ◽  
Author(s):  
Jordan J. Clark ◽  
Parul Sharma ◽  
Eleanor G. Bentley ◽  
Adam C. Harding ◽  
Anja Kipar ◽  
...  
Keyword(s):  
South Africa ◽  
Immune Responses ◽  
Clinical Signs ◽  
Acquired Immunity ◽  
Hamster Model ◽  
Syrian Golden Hamsters ◽  
Subsequent Exposure ◽  
Acquired Immune Responses ◽  
The Uk ◽  
Prior Infection

AbstractThe ability of acquired immune responses against SARS-CoV-2 to protect after subsequent exposure to emerging variants of concern (VOC) such as B1.1.7 and B1.351 is currently of high significance. Here, we use a hamster model of COVID-19 to show that prior infection with a strain representative of the original circulating lineage B of SARS-CoV-2 induces protection from clinical signs upon subsequent challenge with either B1.1.7 or B1.351 viruses, which recently emerged in the UK and South Africa, respectively. The results indicate that these emergent VOC may be unlikely to cause disease in individuals that are already immune due to prior infection, and this has positive implications for overall levels of infection and COVID-19 disease.

scholarly journals Screening, Prevention and Treatment of COVID-19 with Special Reference to African-Americans

2021 ◽  
Vol 2 (3) ◽  
pp. 01-06
Author(s):  
Prabir Mandal
Keyword(s):  
South Africa ◽  
Immune Responses ◽  
Severe Illness ◽  
The Novel ◽  
Novel Variants ◽  
Prevention And Treatment ◽  
Previous Infection ◽  
Flu Virus ◽  
The Uk ◽  
Over Time

Viruses mutate all the time, and the coronavirus that causes COVID-19 is no exception. As new variants of the COVID-19 emerge, a slew of new studies suggest that some may be able to evade immune responses triggered by a previous infection or by a vaccine. The novel variants of SARS-CoV-2 including those seen in the UK (2OI/5O1Y.V1/B.1.1.7), South Africa (2OH/5O1Y.V2/B.1.351), Brazil (P.1/2OJ/5O1Y.V3/B.1.1.248) have emerged with the concern of increased infectivity and virulence. Scientists are working to learn more about the characteristics of these strains whether they could cause more severe illness, and whether currently authorized vaccines will protect people against them. All viruses naturally mutate and evolve over time. For example, flu virus change often, which is why doctors recommend that you get a flu shot every year. Various mRNA vaccine platforms have been developed in recent years and validated in studies of immunogenicity and efficacy.

scholarly journals Attenuated fusogenicity and pathogenicity of SARS-CoV-2 Omicron variant

2022 ◽  
Author(s):  
Kei Sato ◽  
Rigel Suzuki ◽  
Daichi Yamasoba ◽  
Izumi Kimura ◽  
Lei Wang ◽  
...  
Keyword(s):  
South Africa ◽  
Cell Culture ◽  
Severe Acute Respiratory Syndrome ◽  
Global Health ◽  
Cell Fusion ◽  
Statistical Modelling ◽  
Hamster Model ◽  
S Protein ◽  
The Uk ◽  
Cell Cell

Abstract The emergence of a new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant, Omicron, is the most urgent concern in the global health in December 2021. Our statistical modelling estimates that Omicron is >3.0-fold and >5.6-fold more transmissible than Delta in South Africa and the UK, respectively. Intriguingly, cell culture experiments show that Omicron is less fusogenic than Delta and ancestral SARS-CoV-2. Although the spike (S) protein of Delta is efficiently cleaved into the two subunits, which facilitates cell-cell fusion, Omicron S is faintly cleaved. Further, in hamster model, Omicron shows decreased lung infectivity and is less pathogenic compared to Delta and ancestral SARS-CoV-2. Our data suggest that the efficacy of SARS-CoV-2 S cleavage and viral fusogenicity are closely associated with viral pathogenicity, and Omicron evolved to exhibit increased transmissibility and attenuated pathogenicity.

scholarly journals PCR assay to enhance global surveillance for SARS-CoV-2 variants of concern

2021 ◽  
Author(s):  
Chantal B.F. Vogels ◽  
Mallery Breban ◽  
Tara Alpert ◽  
Mary E. Petrone ◽  
Anne E. Watkins ◽  
...  
Keyword(s):  
South Africa ◽  
Immune Responses ◽  
Open Source ◽  
Primary Target ◽  
Pcr Assay ◽  
Gene Target ◽  
Spike Gene ◽  
The World ◽  
The Uk

AbstractWith the emergence of SARS-CoV-2 variants that may increase transmissibility and/or cause escape from immune responses1–3, there is an urgent need for the targeted surveillance of circulating lineages. It was found that the B.1.1.7 (also 501Y.V1) variant first detected in the UK4,5 could be serendipitously detected by the ThermoFisher TaqPath COVID-19 PCR assay because a key deletion in these viruses, spike Δ69-70, would cause a “spike gene target failure” (SGTF) result. However, a SGTF result is not definitive for B.1.1.7, and this assay cannot detect other variants of concern that lack spike Δ69-70, such as B.1.351 (also 501Y.V2) detected in South Africa6 and P.1 (also 501Y.V3) recently detected in Brazil7. We identified a deletion in the ORF1a gene (ORF1a Δ3675-3677) in all three variants, which has not yet been widely detected in other SARS-CoV-2 lineages. Using ORF1a Δ3675-3677 as the primary target and spike Δ69-70 to differentiate, we designed and validated an open source PCR assay to detect SARS-CoV-2 variants of concern8. Our assay can be rapidly deployed in laboratories around the world to enhance surveillance for the local emergence spread of B.1.1.7, B.1.351, and P.1.

scholarly journals Convalescence from prototype SARS-CoV-2 protects Syrian hamsters from disease caused by the Omicron variant

2021 ◽  
Author(s):  
Kathryn A Ryan ◽  
Robert J Watson ◽  
Kevin R Bewley ◽  
Christopher A Burton ◽  
Oliver Carnell ◽  
...  
Keyword(s):  
Weight Loss ◽  
Severe Disease ◽  
Clinical Signs ◽  
Hamster Model ◽  
Initial Infection ◽  
Syrian Hamsters ◽  
Clinical Observations ◽  
Mutation Profile ◽  
Prior Infection ◽  
Induced Immunity

The mutation profile of the SARS-CoV-2 Omicron variant poses a concern for naturally acquired and vaccine-induced immunity. We investigated the ability of prior infection with an early SARS-CoV-2, 99.99% identical to Wuhan-Hu-1, to protect against disease caused by the Omicron variant. We established that infection with Omicron in naive Syrian hamsters resulted in a less severe disease than a comparable dose of prototype SARS-CoV-2 (Australia/VIC01/2020), with fewer clinical signs and less weight loss. We present data to show that these clinical observations were almost absent in convalescent hamsters challenged with the same dose of Omicron 50 days after an initial infection with Australia/VIC01/2020. The data provide evidence for immunity raised against prototype SARS-CoV-2 being protective against Omicron in the Syrian hamster model. Further investigation is required to conclusively determine whether Omicron is less pathogenic in Syrian hamsters and whether this is predictive of pathogenicity in humans.

scholarly journals Genomic Evidence of a Sars-Cov-2 Reinfection Case With E484K Spike Mutation in Brazil

2021 ◽  
Author(s):  
Carolina Kymie Vasques Nonaka ◽  
Marília Miranda Franco ◽  
Tiago Gräf ◽  
Ana Verena Almeida Mendes ◽  
Renato Santana de Aguiar ◽  
...  
Keyword(s):  
South Africa ◽  
Immune Responses ◽  
Neutralizing Antibodies ◽  
Immune Escape ◽  
Viral Evolution ◽  
First Episode ◽  
Receptor Binding Domain ◽  
First Case ◽  
Potential Impact ◽  
The Uk

To date, uncertainty remains about how long the protective immune responses against SARS-CoV-2 persists and the first reports of suspected reinfection began to be described in recovered patients months after the first episode. Viral evolution may favor reinfections, and the recently described spike mutations, particularly in the receptor binding domain (RBD) in SARS-CoV-2 lineages circulating in the UK, South Africa, and most recently in Brazil, have raised concern on their potential impact in infectivity and immune escape. We report the first case of reinfection from genetically distinct SARS-CoV-2 lineage presenting the E484K spike mutation in Brazil, a variant associated with escape from neutralizing antibodies.

International Listening Post report summary: the world at the dawn of 2019

2019 ◽  
Vol 19 (1) ◽  
pp. 121-124
Author(s):  
Sandy Henderson ◽  
Ulrike Beland ◽  
Dimitrios Vonofakos
Keyword(s):  
South Africa ◽  
Faroe Islands ◽  
The South ◽  
The World ◽  
The Uk

On or around 9 January 2019, twenty-two Listening Posts were conducted in nineteen countries: Canada, Chile, Denmark, Faroe Islands, Finland, Germany (Frankfurt and Berlin), Hungary, India, Ireland, Israel, Italy (two in Milan and one in the South), Peru, Serbia, South Africa, Spain, Sweden, Taiwan, Turkey, and the UK. This report synthesises the reports of those Listening Posts and organises the data yielded by them into common themes and patterns.

scholarly journals Drivers of Broad-Spectrum Antibiotic Overuse across Diverse Hospital Contexts—A Qualitative Study of Prescribers in the UK, Sri Lanka and South Africa

Antibiotics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 94
Author(s):  
Carolyn Tarrant ◽  
Andrew M. Colman ◽  
David R. Jenkins ◽  
Edmund Chattoe-Brown ◽  
Nelun Perera ◽  
...  
Keyword(s):  
South Africa ◽  
Sri Lanka ◽  
Antimicrobial Stewardship ◽  
Broad Spectrum ◽  
Low Income ◽  
System Level ◽  
Comparative Approach ◽  
Structured Interviews ◽  
Public And Private ◽  
The Uk

Antimicrobial stewardship programs focus on reducing overuse of broad-spectrum antibiotics (BSAs), primarily through interventions to change prescribing behavior. This study aims to identify multi-level influences on BSA overuse across diverse high and low income, and public and private, healthcare contexts. Semi-structured interviews were conducted with 46 prescribers from hospitals in the UK, Sri Lanka, and South Africa, including public and private providers. Interviews explored decision making about prescribing BSAs, drivers of the use of BSAs, and benefits of BSAs to various stakeholders, and were analyzed using a constant comparative approach. Analysis identified drivers of BSA overuse at the individual, social and structural levels. Structural drivers of overuse varied significantly across contexts and included: system-level factors generating tensions with stewardship goals; limited material resources within hospitals; and patient poverty, lack of infrastructure and resources in local communities. Antimicrobial stewardship needs to encompass efforts to reduce the reliance on BSAs as a solution to context-specific structural conditions.

scholarly journals Shape-shifting and pushing against the odds: staff perceptions of the experiences of first generation students in South Africa and the UK

2021 ◽  
Author(s):  
Rachel Forsyth ◽  
Claire Hamshire ◽  
Danny Fontaine-Rainen ◽  
Leza Soldaat
Keyword(s):  
Higher Education ◽  
South Africa ◽  
First Generation ◽  
Teaching Practice ◽  
First Generation Students ◽  
Staff Perceptions ◽  
Staff Members ◽  
Diversity And Inclusion ◽  
University Life ◽  
The Uk

AbstractThe principles of diversity and inclusion are valued across the higher education sector, but the ways in which these principles are translated into pedagogic practice are not always evident. Students who are first in their family to attend university continue to report barriers to full participation in university life. They are more likely to leave their studies early, and to achieve lower grades in their final qualifications, than students whose families have previous experience of higher education. The purpose of this study was to explore whether a mismatch between staff perceptions and students’ experiences might be a possible contributor to these disparities. The study explored and compared staff discourses about the experiences of first generation students at two universities, one in the United Kingdom (UK), and the other in South Africa (SA). One-to-one interviews were carried out with 40 staff members (20 at each institution) to explore their views about first generation students. The results showed that staff were well aware of challenges faced by first generation students; however, they were unsure of their roles in relation to shaping an inclusive environment, and tended not to consider how to use the assets that they believed first generation students bring with them to higher education. This paper explores these staff discourses; and considers proposals for challenging commonly-voiced assumptions about students and university life in a broader context of diversity and inclusive teaching practice.

scholarly journals William Horner Andrews (1887–1953) – First Professor of Physiology at Onderstepoort

2011 ◽  
Vol 82 (1) ◽  
Author(s):  
D. W. Verwoerd ◽  
W. J. H. Andrews
Keyword(s):  
South Africa ◽  
World War I ◽  
World War ◽  
Snake Venoms ◽  
Field Station ◽  
Guest Worker ◽  
Royal Veterinary College ◽  
Toxic Plants ◽  
The Uk ◽  
Veterinary Laboratory

WHAndrews qualified as a veterinarian in London in 1908 and was recruited soon after, in 1909, by Sir Arnold Theiler to join the staff of the newly established veterinary laboratory at Onderstepoort. After initial studies on the treatment of trypanosomosis and on snake venoms he was deployed by Theiler in 1911 to start research on lamsiekte (botulism)at a field station on the farm Kaffraria near Christiana, where he met and married his wife Doris. After a stint as Captain in the SA Veterinary Corps during World War I he succeeded D T Mitchell as head of the Allerton Laboratory in 1918, where he excelled in research on toxic plants, inter alia identifying Matricaria nigellaefolia as the cause of staggers in cattle.Whenthe Faculty ofVeterinary Science was established in 1920 he was appointed as the first Professor of Physiology. After the graduation of the first class in 1924, and due to health problems, he returned to the UK, first to the Royal Veterinary College and then to the Weybridge Veterinary Laboratories of which he became Director in 1927.After his retirement in 1947 he returned to South Africa as a guest worker at Onderstepoort where he again became involved in teaching physiologywhenProf. Quin unexpectedly died in 1950. Andrews died in Pretoria in 1953 and was buried in the Rebecca Street Cemetery.

scholarly journals Ulcerative balanitis and vulvitis of Dorper sheep in South Africa : a study on its aetiology and clinical features

2005 ◽  
Vol 76 (4) ◽  
Author(s):  
A. Kidanemariam ◽  
J. Gouws ◽  
M. Van Vuuren ◽  
B. Gummow
Keyword(s):  
South Africa ◽  
Clinical Features ◽  
Clinical Signs ◽  
Regular Feature ◽  
Clinically Normal ◽  
Large Colony ◽  
Mycoplasma Mycoides ◽  
Dorper Sheep ◽  
Arcanobacterium Pyogenes ◽  
Apparently Healthy

Ovine ulcerative balanitis and vulvitis in sheep of the Dorper breed has been observed in South Africa since 1979. Its aetiology has not been conclusively resolved, and there is some discrepancy in descriptions of its clinical features. In order to identify the pathogenic microorganism / s that contribute to the occurrence of the disease, the microflora in the genital tracts of both clinically healthy and affected sheep were isolated and compared. Bacteriological examination of materials from affected and unaffected sheep resulted in the isolation of Arcanobacterium pyogenes from 44.2 % and 17.2 % of them respectively. This difference is statistically significant (P < 0.01). Seventy-four per cent of the isolates originated from severe clinical cases. Mycoplasmas were isolated from 49.3 % of 116 clinically normal sheep and 78.2%of 104 affected sheep. There were significant differences in their rates of isolation in clinical groups (P < 0.05). Of all the mycoplasma isolates, Mycoplasma mycoides mycoides large colony variant (MmmLC) was isolated from 61.5 % of clinically diseased sheep while 6.0 % of the isolates were from apparently healthy animals (P < 0.05). The study threw light on the prevalence of mycoplasmas in the genital tract of apparently healthy sheep and, at the same time the identity of the mycoplasma pathogen associated with ulcerative balanitis and vulvitis was revealed. The findings of this investigation therefore confirmed the involvement of mycoplasma, particularly that of MmmLC large colony, in the disease in Dorper sheep in South Africa, and it was concluded that this microorganism is an important pathogen of balanitis and vulvitis in them. The study furthermore demonstrated a probable synergism between A. pyogenes and MmmLC. Finding these 2 organisms together occurred 53.4 times more frequently in the affected sheep than in the unaffected, which emphasises the probable multifactorial nature of the disease. The association between age and the presence of clinical signs was statistically significant. It was found that young sheep were more likely to have lesions than adult sheep. Clinical observations showed that the typical ulceration appears to be confined to the glans penis and lips of the vulva; no ulceration was observed on the shaft of the penis and prepuce or vaginal vestibule. In uncomplicated cases inflammation of the prepuce and vaginal vestibule is not a regular feature of the disease. Therefore the names ulcerative balanitis and vulvitis most accurately describe the nature of the disease in South Africa.

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