Humoral and cellular immunity after the third vaccination against SARS-CoV-2 in hematopoietic stem cell transplant recipients

Background: Protecting vulnerable groups from severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection is of great importance, as they suffer more often from severe or fatal courses. The immune response after a third vaccination is insufficiently studied in patients after hematopoietic stem cell transplantation (HSCT). Method(s): We analyzed the immune response before and after a third vaccination against SARS-CoV-2 in HSCT patients and healthy controls. This is the first report on neutralizing antibodies against 11 variants of SARSCoV- 2, analyzed by competitive fluorescence assay. Humoral immunity was also measured by semi-/quantitative ELISA and neutralization tests. Cellular immunity was assessed using interferon-gamma (IFN-gamma) and inter-leukin-2 (IL-2) ELISpots. Result(s): After the third vaccination, the cellular immune responses were 2.4-fold higher for IFN-gamma in healthy controls vs. HSCT patients, and 3.4- fold higher for IL-2. On average, healthy controls vs. HSCT patients had 1.5-fold higher concentrations of neutralizing antibodies against the variants and 1.6-fold higher antibody ratios and 4.4-fold higher antibody concentrations against wild-type SARS-CoV-2. Conclusion(s): We show that immune responses of HSCT patients are significantly lower vs. healthy controls, but HSCT patients also exhibit neutralizing antibodies to variants of SARS-CoV-2. Our findings may contribute to the adaptation of vaccination strategies and further protective measures for immunocompromised individuals.

Humoral and Cellular Immunity against Different Sars-Cov-2 Variants Is Detectable but Reduced in Vaccinated Kidney Transplant Recipients

Solid organ transplant recipients have an increased morbidity and mortality after SARS-CoV-2 infection. Immune responses after the third/fourth vaccination against SARS-CoV-2 are insufficiently studied in patients after kidney transplantation (KTX). We analyzed immune responses at a median of 4 months after the third/fourth vaccination in KTX patients and compared them to healthy controls. Cellular immunity was assessed using interferon-gamma (IFN-gamma) and interleukin-2 (IL-2) ELISpot assays. Neutralizing antibody titers were assessed against SARS-CoV-2 D614G (wild type) and the variants alpha, delta and omicron by a cell culture-based neutralization assay. Humoral immunity was also determined by a competitive fluorescence assay, using 11 different variants of SARS-CoV-2. Antibody ratios were measured by ELISA. KTX patients showed significantly lower SARSCoV- 2-specific IFN-gamma responses after booster vaccination than healthy controls. However, the SARS-CoV-2 specific IL-2 responses were comparable to the T cell responses of healthy controls. Cell culture-based neutralizing antibody titers were 1.3-fold higher in healthy controls for D614G, alpha and delta and 7.8-fold higher for omicron (p < 0.01). Healthy controls had approximately 2-fold higher concentrations of potential neutralizing antibodies against all 11 variants than KTX patients. However, more than 60% of the KTX patients exhibited antibodies to variants of SARS-CoV-2. In conclusion, KTX patients should be partly protected against SARSCoV- 2, either by cross-reactive T cells, especially those producing IL-2, or by neutralizing antibodies to SARSCoV- 2 variants.

Virucidal efficacy of different formulations for hand and surface disinfection targeting SARS CoV-2.

In the ongoing SARS CoV-2 pandemic, effective disinfection measures are needed, and guidance based on the methodological framework of the European Committee for Standardization (CEN) may enable the choice of effective disinfectants on an immediate basis. This study aimed to elucidate whether disinfectants claiming 'virucidal activity against enveloped viruses' as specified in the European Standard EN 14476 as well as in the German Association for the Control of Viral Diseases/Robert Koch Institute (DVV/RKI) guideline are effectively inactivating SARS-CoV-2. Two commercially available formulations for surface disinfection and one formulation for hand disinfection were studied regarding their virucidal activity. Based on the data of this study the enveloped SARS-CoV-2 is at least equally susceptible compared to the standard test virus vaccinia used in the EN 14476 and DVV/RKI guidelines. Thus, chemical disinfectants claiming 'virucidal activity against enveloped viruses' based on the EN 14476 and DVV/RKI guidelines will be an effective choice to target enveloped SARS-CoV-2 as a preventive measure.

Comparison of the in-vitro efficacy of different mouthwash solutions targeting SARS-CoV-2 based on the European Standard EN 14476

The outbreak of the SARS-CoV-2 pandemic is triggering a global health emergency alert. Until vaccination becomes available, a bundle of effective preventive measures is desperately needed. Recent research is indicating the relevance of aerosols in the spread of SARS-CoV-2. Thus, in this study commercially available antiseptic mouthwashes based on the active ingredients chlorhexidine digluconate and octenidine dihydrochloride (OCT) were investigated regarding their efficacy against SARS-CoV-2 using the European Standard 14476. Based on the requirement of EN 14476 in which reduction of at least four decimal logarithms (>=4 log₁₀) of viral titre is requested to state efficacy, the OCT-based formulation was found to be effective within a contact time of only 15 s against SARS-CoV-2. Based on this in-vitro data the OCT mouthwash thus constitutes an interesting candidate for future clinical studies to prove its effectiveness in a potential prevention of SARS-CoV-2 transmission by aerosols.

Torsion field - An example of pseudo-scientific concept in physics

The article outlines the assumptions of the theory of torsion fields treated in the scientific community as an element of pseudoscience. This topic is important due to the emergence of conspiracy theories related to the introduction of a new generation of mobile telephony, which is a natural development of technology, and the dissemination of false information about the spread of viruses, including Covid-19. The presented opinion of the authors is a contribution to the educational process aiming at the elimination of the conspiracy theories from the society. © 2021 Wydawnictwo SIGMA-NOT. All rights reserved.