Virological traits of the SARS-CoV-2 BA.2.87.1 lineage (preprint)

The highly mutated SARS-CoV-2 BA.2.87.1 lineage was recently detected in South Africa, but its transmissibility is unknown. Here, we report that BA.2.87.1 efficiently enters human cells but is more sensitive to antibody-mediated neutralization than the currently dominating JN.1 variant. Acquisition of adaptive mutations might thus be needed for high transmissibility.

"There is no one who helps you with it." Experiences of people with long COVID regarding medical care, therapeutic measures, and barriers in the German healthcare system: results of a qualitative study with four focus groups (preprint)

Background Many people experience long-term symptoms such as fatigue, cognitive problems, or shortness of breath after an acute infection with COVID-19. This emerging syndrome, known as long COVID, is new and complex in many aspects. This study aims to collect the experiences of people with long COVID with ambulatory healthcare structures. Methods Four focus groups were conducted with a total of 23 adults with long COVID in June and July 2022. These discussions were audio-recorded, subsequently transcribed, and analyzed using the qualitative content analysis of Mayring and Kuckartz. Results Fourteen out of 19 participants who had a primary care encounter regarding their long COVID symptoms did not perceive it as helpful. Many respondents reported that their general practitioners did not take their long COVID symptoms seriously and did not refer them to specialists or made therapeutic recommendations. However, some participants reported that they were prescribed non-pharmaceutical therapies (e.g., group meetings supported by psychotherapists, occupational therapy, etc.) that improved their condition. 14 of 23 respondentsperceived care barriers such as providers' lack of awareness of long COVID, poor access to specialists, a lack of specialized care (e.g., long COVID clinics), or high bureaucratic hurdles for specific healthcare services. To improve medical care, participants suggested campaigns to raise awareness of long COVID among healthcare providers and the general population, increase research and government investments regarding the development of treatment structures for long COVID, expanding existing therapeutic services, and establishing one-stop shops for integrated specialist healthcare for people with long COVID. Conclusions Several implications for healthcare professionals and policymakers can be derived from this study: (1) general practitioners should take the symptoms of long COVID seriously, assume a care coordinating role, make referrals, and establish contact with long COVID clinics; (2) care planners should focus on developing interprofessional evidence-based care and treatment approaches for long COVID; (3) existing care structures such as long COVID outpatient clinics should be expanded. Trial registration: The study is registered in the German register for clinical trials (DRKS00026007).

Migrant healthcare workers during COVID-19: bringing an intersectional health system-related approach into pandemic protection. A German case study (preprint)

Introduction: Migrant healthcare workers played an important role during the COVID-19 pandemic, but data are lacking especially for high-resourced European healthcare systems. This study aims to research migrant healthcare workers through an intersectional health system-related approach, using Germany as a case study. Methods. An intersectional research framework was created and a rapid scoping study performed. Secondary analysis of selected items taken from two COVID-19 surveys was undertaken to compare perceptions of national and foreign-born healthcare workers, using descriptive statistics. Results. Available research is focused on worst-case pandemic scenarios of Brazil and the United Kingdom, highlighting racialised discrimination and higher risks of migrant healthcare workers. The German data did not reveal significant differences between national-born and foreign-born healthcare workers for items related to health status including SARS-CoV-2 infection and vaccination, and perception of infection risk, protective workplace measures, and government measures, but items related to social participation and work conditions with higher infection risk indicate a higher burden of migrant healthcare workers. Conclusions. COVID-19 pandemic policy must include migrant healthcare workers, but simply adding the migration status is not enough. We introduce an intersectional health systems-related approach to understand how pandemic policies create social inequalities and how the protection of migrant healthcare workers may be improved.

Healthcare workers perceptions and medically approved COVID-19 infection risk: understanding the mental health dimension of the pandemic. A German hospital case study (preprint)

Introduction. This 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. Methods. We 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. Results. The 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. Conclusions. A 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.

BNT162b2 boosted immune responses six months after heterologous or homologous ChAdOx1nCoV-19/BNT162b2 vaccination against COVID-19 (preprint)

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.

BNT162b2 boosted immune responses six months after heterologous or homologous ChAdOx1nCoV-19/BNT162b2 vaccination against COVID-19 (preprint)

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.

The Omicron variant is highly resistant against antibody-mediated neutralization - implications for control of the COVID-19 pandemic (preprint)

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.

Diminishing immune responses against variants of concern in dialysis patients four months after SARS-CoV-2 mRNA vaccination (preprint)

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.

Humoral and cellular immune response against SARS-CoV-2 variants following heterologous and homologous ChAdOx1 nCoV-19/BNT162b2 vaccination. (preprint)

Cerebral venous thrombosis was reported as a rare but serious adverse event in young and middle-aged vaccinees following immunization with AstraZeneca’s ChAdOx1-nCov-19 vaccine. As a consequence, several European governments recommended using this vaccine only in individuals older than 60 years leaving millions of ChAd primed individuals with the decision to either receive a second shot of ChAd or a heterologous boost with mRNA-based vaccines. However, such combinations have not been tested so far. We used Hannover Medical School’s COVID-19 Contact (CoCo) Study cohort of health care professionals (HCP) to monitor ChAd primed immune responses before and three weeks after booster with ChAd or BioNTech/Pfizer’s BNT162b2. Whilst both vaccines boosted prime-induced immunity, BNT induced significantly higher frequencies of Spike-specific CD4 and CD8 T cells and, in particular, high titers of neutralizing antibodies against the B.1.1.7, B.1.351 and the P.1 variants of concern of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2).

Cellular and humoral immunogenicity of a SARS-CoV-2 mRNA vaccine in patients on hemodialysis (preprint)

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.