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IntroductionThis study analyses how healthcare workers (HCWs) perceived risks, protection and preventive measures during the COVID-19 pandemic in relation to medically approved risks and organisational measures. The aim is to explore blind spots of pandemic protection and make mental health needs of HCWs visible. MethodsWe have chosen an optimal-case scenario of a high-income country with a well-resourced hospital sector and low HCW infection rate at the organisational level to explore governance gaps in HCW protection. A German multi-method hospital study at Hannover Medical School served as empirical case; document analysis, expert information and survey data (n=1163) were collected as part of a clinical study into SARS-CoV-2 serology testing during the second wave of the pandemic (November 2020-February 2021). Selected survey items included perceptions of risks, protection and preventive measures. Descriptive statistical analysis and regression were undertaken for gender, profession and COVID-19 patient care. ResultsThe results reveal a low risk of 1% medically approved infections among participants, but a much higher mean personal risk estimate of 15%. The majority (68.4%) expressed some to very strong fear of acquiring infection at the workplace. Individual protective behaviour and compliance with protective workplace measures were estimated as very high. Yet only about half of the respondents felt strongly protected by the employer; 12% even perceived no or little protection. Gender and contact with COVID-19 patients had no significant effect on the estimations of infection risks and protective workplace behaviour, but nursing was correlated with higher levels of personal risk estimations and fear of infection. ConclusionsA strong mismatch between low medically approved risk and personal risk perceptions of HCWs brings stressors and threats into view, that may be preventable through better information and risk communication and through investment in mental health and inclusion in pandemic preparedness plans.
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Reports suggest that COVID-19 vaccine effectiveness is decreasing, either due to waning immune protection, emergence of new variants of concern, or both. Heterologous prime/boost vaccination with a vector-based approach (ChAdOx-1nCov-19, ChAd) followed by an mRNA vaccine (e.g. BNT162b2, BNT) appeared to be superior in inducing protective immunity, and large scale second booster vaccination is ongoing. However, data comparing declining immunity after homologous and heterologous vaccination as well as effects of a third vaccine application after heterologous ChAd/BNT vaccination are lacking. We longitudinally monitored immunity in ChAd/ChAd (n=41) and ChAd/BNT (n=88) vaccinated individuals and assessed the impact of a second booster with BNT in both groups. The second booster greatly augmented waning anti-spike IgG but only moderately increased spike-specific CD4+ and CD8+ T cells in both groups to cell frequencies already present after the boost. More importantly, the second booster efficiently restored neutralizing antibody responses against Alpha, Beta, Gamma, and Delta, but neutralizing activity against B.1.1.529 (Omicron) stayed severely impaired. Our data suggest that inferior SARS-CoV-2 specific immune responses after homologous ChAd/ChAd vaccination can be cured by a heterologous BNT vaccination. However, prior heterologous ChAd/BNT vaccination provides no additional benefit for spike-specific T cell immunity or neutralizing Omicron after the second boost.
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The rapid spread of the SARS-CoV-2 Omicron variant suggests that the virus might become globally dominant. Further, the high number of mutations in the viral spike-protein raised concerns that the virus might evade antibodies induced by infection or vaccination. Here, we report that the Omicron spike was resistant against most therapeutic antibodies but remained susceptible to inhibition by Sotrovimab. Similarly, the Omicron spike evaded neutralization by antibodies from convalescent or BNT162b2-vaccinated individuals with 10- to 44-fold higher efficiency than the spike of the Delta variant. Neutralization of the Omicron spike by antibodies induced upon heterologous ChAdOx1/BNT162b2-vaccination or vaccination with three doses of BNT162b2 was more efficient, but the Omicron spike still evaded neutralization more efficiently than the Delta spike. These findings indicate that most therapeutic antibodies will be ineffective against the Omicron variant and that double immunization with BNT162b2 might not adequately protect against severe disease induced by this variant.
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Patients undergoing chronic hemodialysis were among the first to receive SARS-CoV-2 vaccinations due to their increased risk for severe COVID-19 disease and high case fatality rates. To date, there have been minimal longitudinal studies in hemodialysis patients to ascertain whether protection offered by vaccination is long-lasting. To assess how surrogates for protection changed over time, we examined both the humoral and cellular response in a previously reported cohort of at-risk hemodialysis patients and healthy donors, four months after their second dose of Pfizer BNT162b2. Compared to three weeks post-second vaccination, both cellular and humoral responses against the original SARS-CoV-2 isolate as well as variants of concern were significantly reduced, with some dialyzed individuals having no B- or T-cell response. Our data strongly support the need for a third booster in hemodialysis patients and potentially other at-risk individuals.
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BackgroundPatients with chronic renal insufficiency on intermittent hemodialysis face an increased risk of COVID-19 induced mortality and impaired vaccine responses. To date, only few studies addressed SARS-CoV-2 vaccine elicited immunity in this immunocompromised population. MethodsWe assessed immunogenicity of the mRNA vaccine BNT162b2 in at risk dialysis patients and characterized systemic cellular and humoral immune responses in serum and saliva using interferon {gamma} release assay and multiplex-based cytokine and immunoglobulin measurements. We further compared binding capacity and neutralization efficacy of vaccination-induced immunoglobulins against emerging SARS-CoV-2 variants of concern B.1.1.7, B.1.351, B.1.429 and Cluster 5 by ACE2-RBD competition assay. FindingsPatients on intermittent hemodialysis exhibit detectable but variable cellular and humoral immune responses against SARS-CoV-2 and variants of concern after a two-dose regimen of BNT162b2. Although vaccination-induced immunoglobulins were detectable in saliva and plasma, both anti-SARS-CoV-2 IgG and neutralization efficacy was reduced compared to controls. Similarly, T-cell mediated interferon {gamma} release after stimulation with SARS-CoV-2 spike peptides was significantly diminished. InterpretationQuantifiable humoral and cellular immune responses after BNT162b2 vaccination in individuals on intermittent dialysis are encouraging, but urge for longitudinal follow-up to assess longevity of immunity. Diminished virus neutralization and interferon {gamma} responses in face of emerging variants of concern may favor this at risk population for re-vaccination using modified vaccines at the earliest opportunity. FundingInitiative and Networking Fund of the Helmholtz Association of German Research Centers, EU Horizon 2020 research and innovation program, State Ministry of Baden-Wurttemberg for Economic Affairs, Labor and Tourism. Research in the contextO_ST_ABSEvidence before this studyC_ST_ABSPatients on dialysis tend to have a reduced immune response to both infection and vaccination. We searched PubMed and MedRxiv for studies including search terms such as "COVID-19", "vaccine", and "dialysis" but no peer-reviewed studies to date assessed both SARS-CoV-2 specific B- and T-cell responses, mucosal immunoglobulins, and considered the impact of SARS-CoV-2 variants of concern in this at risk population. Added value of the studyWe provide a comprehensive functional characterization of both T- and B-cell responses following a two-dose regimen of BNT162b2 in at risk patients on maintenance hemodialysis. More importantly, to the best of our knowledge, we assess for the first time binding and neutralization capacity of vaccination-induced circulation and mucosal antibodies towards emerging SARS-CoV-2 variants of concern in an immunocompromised population. Implications of all the available evidencePatients on maintenance hemodialysis develop a substantial cellular and humoral immune response following the BNT162b2 vaccine. These findings should encourage patients on intermittent hemodialysis to receive the vaccine. However, we suggest continuing additional protection measures against variants of concern in this at risk population until longevity of the vaccine response is fully evaluated.
