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1.
Embase; 2021.
Preprint in English | EMBASE | ID: ppcovidwho-330496

ABSTRACT

The Janssen (Johnson & Johnson) Ad26.COV2.S non-replicating viral vector vaccine has been widely deployed for COVID-19 vaccination programs in resource-limited settings. Here we confirm that neutralizing and binding responses to Ad26.COV2.S vaccination are stable for 6 months post-vaccination, when tested against multiple SARS-CoV-2 variants. Secondly, using longitudinal samples from individuals who experienced clinically mild breakthrough infections 4 to 5 months after vaccination, we show dramatically boosted binding antibodies, Fc effector function and neutralization. These high titer responses are of similar magnitude to humoral immune responses measured in severely ill, hospitalized donors, and are cross-reactive against diverse SARS-CoV-2 variants, including the extremely neutralization resistant Omicron (B.1.1.529) variant that currently dominates global infections, as well as SARS-CoV-1. These data have implications for population immunity in areas where the Ad26.COV2.S vaccine has been widely deployed, but where ongoing infections continue to occur at high levels.

2.
Embase;
Preprint in English | EMBASE | ID: ppcovidwho-326997

ABSTRACT

The SARS-CoV-2 Omicron variant has multiple Spike (S) protein mutations that contribute to escape from the neutralizing antibody responses, and reducing vaccine protection from infection. The extent to which other components of the adaptive response such as T cells may still target Omicron and contribute to protection from severe outcomes is unknown. We assessed the ability of T cells to react with Omicron spike in participants who were vaccinated with Ad26.CoV2.S or BNT162b2, and in unvaccinated convalescent COVID-19 patients (n = 70). We found that 70-80% of the CD4 and CD8 T cell response to spike was maintained across study groups. Moreover, the magnitude of Omicron cross-reactive T cells was similar to that of the Beta and Delta variants, despite Omicron harbouring considerably more mutations. Additionally, in Omicron-infected hospitalized patients (n = 19), there were comparable T cell responses to ancestral spike, nucleocapsid and membrane proteins to those found in patients hospitalized in previous waves dominated by the ancestral, Beta or Delta variants (n = 49). These results demonstrate that despite Omicron’s extensive mutations and reduced susceptibility to neutralizing antibodies, the majority of T cell response, induced by vaccination or natural infection, crossrecognises the variant. Well-preserved T cell immunity to Omicron is likely to contribute to protection from severe COVID-19, supporting early clinical observations from South Africa.

3.
American Journal of Public Health ; 111(12):2086-2086, 2021.
Article in English | Web of Science | ID: covidwho-1688257
5.
S Afr Med J ; 110(7): 625-628, 2020 06 17.
Article in English | MEDLINE | ID: covidwho-743569

ABSTRACT

The COVID-19 pandemic has brought discussions around the appropriate and fair rationing of scare resources to the forefront. This is of special importance in a country such as South Africa (SA), where scarce resources interface with high levels of need. A large proportion of the SA population has risk factors associated with worse COVID-19 outcomes. Many people are also potentially medically and socially vulnerable secondary to the high levels of infection with HIV and tuberculosis (TB) in the country. This is the second of two articles. The first examined the clinical evidence regarding the inclusion of HIV and TB as comorbidities relevant to intensive care unit (ICU) admission triage criteria. Given the fact that patients with HIV or TB may potentially be excluded from admission to an ICU on the basis of an assumption of lack of clinical suitability for critical care, in this article we explore the ethicolegal implications of limiting ICU access of persons living with HIV or TB. We argue that all allocation and rationing decisions must be in terms of SA law, which prohibits unfair discrimination. In addition, ethical decision-making demands accurate and evidence-based strategies for the fair distribution of limited resources. Rationing decisions and processes should be fair and based on visible and consistent criteria that can be subjected to objective scrutiny, with the ultimate aim of ensuring accountability, equity and fairness.


Subject(s)
Coronavirus Infections , HIV Infections/epidemiology , Health Care Rationing/methods , Intensive Care Units , Pandemics , Patient Selection/ethics , Pneumonia, Viral , Resource Allocation , Triage , Tuberculosis/epidemiology , Betacoronavirus/isolation & purification , COVID-19 , Coinfection , Coronavirus Infections/economics , Coronavirus Infections/epidemiology , Coronavirus Infections/therapy , Health Services Needs and Demand/organization & administration , Humans , Intensive Care Units/economics , Intensive Care Units/standards , Pandemics/economics , Pneumonia, Viral/economics , Pneumonia, Viral/epidemiology , Pneumonia, Viral/therapy , Resource Allocation/ethics , Resource Allocation/legislation & jurisprudence , SARS-CoV-2 , South Africa/epidemiology , Triage/economics , Triage/ethics , Triage/legislation & jurisprudence
6.
S Afr Med J ; 110(7): 621-624, 2020 06 17.
Article in English | MEDLINE | ID: covidwho-743568

ABSTRACT

Infectious diseases pandemics have devastating health, social and economic consequences, especially in developing countries such as South Africa. Scarce medical resources must often be rationed effectively to contain the disease outbreak. In the case of COVID-19, even the best-resourced countries will have inadequate intensive care facilities for the large number of patients needing admission and ventilation. The scarcity of medical resources creates the need for national governments to establish admission criteria that are evidence-based and fair. Questions have been raised whether infection with HIV or tuberculosis (TB) may amplify the risk of adverse COVID-19 outcomes and therefore whether these conditions should be factored in when deciding on the rationing of intensive care facilities. In light of these questions, clinical evidence regarding inclusion of these infections as comorbidities relevant to intensive care unit admission triage criteria is investigated in the first of a two-part series of articles. There is currently no evidence to indicate that HIV or TB infection on their own predispose to an increased risk of infection with SARS-CoV-2 or worse outcomes for COVID-19. It is recommended that, as for other medical conditions, validated scoring systems for poor prognostic factors should be applied. A subsequent article examines the ethicolegal implications of limiting intensive care access of persons living with HIV or TB.


Subject(s)
Coronavirus Infections , HIV Infections/epidemiology , Health Care Rationing/methods , Intensive Care Units , Pandemics , Pneumonia, Viral , Triage/organization & administration , Tuberculosis/epidemiology , Betacoronavirus/isolation & purification , COVID-19 , Coinfection , Coronavirus Infections/economics , Coronavirus Infections/epidemiology , Coronavirus Infections/therapy , Health Services Needs and Demand/organization & administration , Humans , Intensive Care Units/economics , Intensive Care Units/standards , Pandemics/economics , Patient Selection , Pneumonia, Viral/economics , Pneumonia, Viral/epidemiology , Pneumonia, Viral/therapy , Prognosis , Risk Assessment , SARS-CoV-2 , South Africa/epidemiology
7.
SAMJ: South African Medical Journal ; 110(7):1-6, 2020.
Article | WHO COVID | ID: covidwho-664789

ABSTRACT

Pandemics challenge clinicians and scientists in many ways, especially when the virus is novel and disease expression becomes variable or unpredictable. Under such circumstances, research becomes critical to inform clinical care and protect future patients. Given that severely ill patients admitted to intensive care units are at high risk of mortality, establishing the cause of death at a histopathological level could prove invaluable in contributing to the understanding of COVID-19. Postmortem examination including autopsies would be optimal. However, in the context of high contagion and limited personal protective equipment, full autopsies are not being conducted in South Africa (SA). A compromise would require tissue biopsies and samples to be taken immediately after death to obtain diagnostic information, which could potentially guide care of future patients, or generate hypotheses for finding needed solutions. In the absence of an advance written directive (including a will or medical record) providing consent for postmortem research, proxy consent is the next best option. However, obtaining consent from distraught family members, under circumstances of legally mandated lockdown when strict infection control measures limit visitors in hospitals, is challenging. Their extreme vulnerability and emotional distress make full understanding of the rationale and consent process difficult either before or upon death of a family member. While it is morally distressing to convey a message of death telephonically, it is inhumane to request consent for urgent research in the same conversation. Careful balancing of the principles of autonomy, non-maleficence and justice becomes an ethical imperative. Under such circumstances, a waiver of consent, preferably followed by deferred proxy consent, granted by a research ethics committee in keeping with national ethics guidance and legislation, would fulfil the basic premise of care and research: first do no harm. This article examines the SA research ethics framework, guidance and legislation to justify support for a waiver of consent followed by deferred proxy consent, when possible, in urgent research after death to inform current and future care to contain the pandemic in the public interest.

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