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1.
Topics in Antiviral Medicine ; 30(1 SUPPL):18, 2022.
Article in English | EMBASE | ID: covidwho-1880294

ABSTRACT

Background: The Sisonke Phase IIIB open-label implementation study vaccinated health care workers (HCWs) with the single dose Ad26.COV2.S vaccine during two phases of the South African Covid-19 epidemic, dominated first by the Beta followed by the Delta variant of concern. Methods: HCWs were vaccinated over 3 months (17 February-17 May 2021). Safety was monitored by self-reporting, facility reporting and linkage to national databases. Vaccine effectiveness (VE) against Covid-19 related hospitalisation, hospitalisation requiring critical or intensive care and death, ascertained 28 days or more post vaccination was assessed up until 17 July 2021. Nested sub-cohorts (A and B) from two national medical schemes were evaluated to assess VE using a matched retrospective cohort design. Results: Over the 3-month period, 477234 HCWs were vaccinated in 122 vaccination sites across South Africa. VE derived from the sub-cohorts comprising 215 813 HCWs was 83% (95% CI 75-89) to prevent Covid-19 deaths, 75% (95% CI 69-82) to prevent hospital admissions requiring critical or intensive care and 67% (95% CI 62-71) to prevent Covid-19 related hospitalisations. The VE was maintained in older HCWs and those with comorbidities including HIV infection. VE remained consistent throughout the Beta and Delta dominant phases of the study. 10279 adverse events were reported and 139 (1.4%) were serious, including two cases of thrombosis with thrombocytopenia syndrome and four cases of Guillain-Barré syndrome who recovered. Conclusion: The single dose Ad26.COV2.S was safe and effective against severe Covid-19 disease and death post-vaccination, and against both Beta and Delta variants providing real-world evidence for its use globally.

2.
Topics in Antiviral Medicine ; 30(1 SUPPL):380, 2022.
Article in English | EMBASE | ID: covidwho-1880274

ABSTRACT

Background: We aimed to examine concerns surrounding COVID-19 infection and healthcare access among South African young people (YP) living with HIV (YPLWH) and HIV-uninfected YP with the goal of identifying differences between groups. Methods: We examined cross-sectional data from the baseline procedures of the BUDDY study conducted among YP (13-24 years) living with and without HIV in Cape Town, South Africa from February-September 2021. YPLWH were recruited from an HIV clinic and HIV-uninfected YP were recruited through community outreach. Adjusted prevalence ratios (aPRs) were computed to estimate associations between HIV cohort and COVID-19 testing, vaccine acceptance, and access to healthcare services since March 2020 controlling for participant age and gender. Results: A total of 535 participants were enrolled into the study, including 217 YPLWH and 318 HIV-uninfected YP. The median age, 19.1 years (IQR=16.6-21.5), was similar between groups. YPLWH were 58% female and HIV-uninfected YP were 78% female (p<.001). YPLWH were less than half as likely than HIV-uninfected YP to have received a COVID-19 test (6% vs 12%, aPR=0.48, 95% CI 0.26-0.89), to be willing to accept a COVID-19 vaccine (49% vs 59%, aPR=0.84, 95% CI 0.71-0.99), and to be concerned about becoming severely ill from COVID-19 (60% vs 76%, aPR=0.79, 95% CI 0.69-0.89). Perceived risk of becoming infected with COVID-19 in the next month was similar between YPLWH and HIV-uninfected YP (32% vs 36%). YPLWH were more likely than HIV-uninfected YP to report being unable to attend a healthcare appointment (27% vs 20%, aPR=1.39, 95% CI 1.01-1.90). Further, a greater proportion of YPLWH attempted to access condoms (aPR=1.51, 95% CI 1.32-1.74) and HIV/STI testing services (aPR=1.58, 95% CI 1.38-1.80) than HIV-uninfected YP and, among females who attempted to access contraceptives services, YPLYW reported significantly lower access than HIV-uninfected YP (aPR=0.82, 95% CI 0.71-0.94) (Table 1). Last, among YPLWH, 28% reported missing an HIV care appointment, 14% reported running out of their HIV medication, and 34% reported they were worried about running out of their medication since March 2020. Conclusion: Experiences living with HIV may shape concerns around COVID-19 infection among YP. YPLWH reported greater health-seeking behavior than HIV-uninfected YP and a significant proportion reported missing an appointment and running out of their HIV medication. Services should devise strategies to prevent interruptions in healthcare access among YP.

3.
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.

4.
South African Medical Journal ; 112(2 b), 2022.
Article in English | EMBASE | ID: covidwho-1706330

ABSTRACT

Sisonke is a multicentre, open-label, single-arm phase 3B vaccine implementation study of healthcare workers (HCWs) in South Africa, with prospective surveillance for 2 years. The primary endpoint is the rate of severe COVID-19, including hospitalisations and deaths. The Sisonke study enrolled and vaccinated participants nationally at potential vaccination roll-out sites between 17 February and 26 May 2021. After May 2021, additional HCWs were vaccinated as part of a sub-study at selected clinical research sites. We discuss 10 lessons learnt to strengthen national and global vaccination strategies: (i) consistently advocate for vaccination to reduce public hesitancy;(ii) an electronic vaccination data system (EVDS) is critical;(iii) facilitate access to a choice of vaccination sites, such as religious and community centres, schools, shopping malls and drive-through centres;(iv) let digitally literate people help elderly and marginalised people to register for vaccination;(v) develop clear 'how to' guides for vaccine storage, pharmacy staff and vaccinators;(vi) leverage instant messaging platforms, such as WhatsApp, for quick communication among staff at vaccination centres;(vii) safety is paramount - rapid health assessments are needed at vaccination centres to identify people at high risk of serious adverse events, including anaphylaxis or thrombosis with thrombocytopenia syndrome. Be transparent about adverse events and contextualise vaccination benefits, while acknowledging the small risks;(viii) provide real-time, responsive support to vaccinees post vaccination and implement an accessible national vaccine adverse events surveillance system;(ix) develop efficient systems to monitor and investigate COVID-19 breakthrough infections;and (x) flexibility and teamwork are essential in vaccination centres across national, provincial and district levels and between public and private sectors.

5.
Embase;
Preprint in English | EMBASE | ID: ppcovidwho-327037

ABSTRACT

Following the results of the ENSEMBLE 2 study, which demonstrated improved vaccine efficacy of a two-dose regimen of Ad26.COV.2 vaccine given 2 months apart, we expanded the Sisonke study which had provided single dose Ad26.COV.2 vaccine to almost 500 000 health care workers (HCW) in South Africa to include a booster dose of the Ad26.COV.2. Sisonke 2 enrolled 227 310 HCW from the 8 November to the 17 December 2021. Enrolment commenced before the onset of the Omicron driven fourth wave in South Africa affording us an opportunity to evaluate early VE in preventing hospital admissions of a homologous boost of the Ad26.COV.2 vaccine given 6-9 months after the initial vaccination in HCW. We estimated vaccine effectiveness (VE) of the Ad26.COV2.S vaccine booster in 69 092 HCW as compared to unvaccinated individuals enrolled in the same managed care organization using a test negative design. We compared VE against COVID19 admission for omicron during the period 15 November to 20 December 2021. After adjusting for confounders, we observed that VE for hospitalisation increased over time since booster dose, from 63% (95%CI 31-81%);to 84% (95% CI 67-92%) and then 85% (95% CI: 54-95%), 0-13 days, 14-27 days, and 1-2 months post-boost. We provide the first evidence of the effectiveness of a homologous Ad26.COV.2 vaccine boost given 6-9 months after the initial single vaccination series during a period of omicron variant circulation. This data is important given the increased reliance on the Ad26.COV.2 vaccine in Africa.

6.
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.

7.
S Afr Med J ; 112(2b): 13486, 2021 12 24.
Article in English | MEDLINE | ID: covidwho-1678836

ABSTRACT

Sisonke is a multicentre, open-label, single-arm phase 3B vaccine implementation study of healthcare workers (HCWs) in South Africa, with prospective surveillance for 2 years. The primary endpoint is the rate of severe COVID­19, including hospitalisations and deaths. The  Sisonke study enrolled and vaccinated participants nationally at potential vaccination roll-out sites between 17 February and 26 May 2021. After May 2021, additional HCWs were vaccinated as part of a sub-study at selected clinical research sites. We discuss 10 lessons learnt to strengthen national and global vaccination strategies:(i) consistently advocate for vaccination to reduce public hesitancy; (ii) an electronic vaccination data system (EVDS) is critical; (iii) facilitate access to a choice of vaccination sites, such as religious and community centres, schools, shopping malls and drive-through centres; (iv) let digitally literate people help elderly and marginalised people to register for vaccination; (v) develop clear 'how to' guides for vaccine storage, pharmacy staff and vaccinators; (vi) leverage instant messaging platforms, such as WhatsApp, for quick communication among staff at vaccination centres; (vii) safety is paramount - rapid health assessments are needed at vaccination centres to identify people at high risk of serious adverse events, including anaphylaxis or thrombosis with thrombocytopenia syndrome. Be transparent about adverse events and contextualise vaccination benefits, while acknowledging the small risks; (viii) provide real-time, responsive support to vaccinees post vaccination and implement an accessible national vaccine adverse events surveillance system; (ix) develop efficient systems to monitor and investigate COVID­19 breakthrough infections; and (x) flexibility and teamwork are essential in vaccination centres across national, provincial and district levels and between public and private sectors.


Subject(s)
COVID-19 Vaccines/administration & dosage , COVID-19/prevention & control , Health Personnel , Infectious Disease Transmission, Patient-to-Professional/prevention & control , Mass Vaccination , Humans , Prospective Studies , SARS-CoV-2 , South Africa/epidemiology
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