Anti-SARS-CoV-2 IgG Antibodies Post-COVID-19 or Post-Vaccination in Libyan Population: Comparison of Four Vaccines.

Measurement of strength and durability of SARS-COV-2 antibody response is important to understand the waning dynamics of immune response to both vaccines and infection. The study aimed to evaluate the level of IgG antibodies against SARS-CoV-2 and their persistence in recovered, naïve, and vaccinated individuals. We investigated anti-spike RBD IgG antibody responses in 10,000 individuals, both following infection with SARS-CoV-2 and immunization with SARS-COV-2 AstraZeneca, Sputnik V, Sinopharm, and Sinovac. The mean levels of anti-spike IgG antibodies were higher in vaccinated participants with prior COVID-19 than in individuals without prior COVID-19. Overall, antibody titers in recovered vaccinee and naïve vaccinee persisted beyond 20 weeks. Vaccination with adenoviral-vector vaccines (AstraZeneca and Sputnik V) generates higher antibody titers than with killed virus vaccine (Sinopharm and Sinovac). Approximately two-thirds of asymptomatic unvaccinated individuals had developed virus-specific antibodies. A single dose of vaccine is likely to provide greater protection against SARS-CoV-2 infection in individuals with apparent prior SARS-CoV-2 infection, than in SARS-CoV-2-naive individuals. In addition, the high number of seropositivity among asymptomatic unvaccinated individuals showed that the number of infections are probably highly underestimated. Those vaccinated with inactivated vaccine may require more frequent boosters than those vaccinated with adenoviral vaccine. These findings are important for formulating public health vaccination strategies during COVID-19 pandemic.

Parents' concerns and attitudes towards school reopening during COVID-19 pandemic: a cross-sectional survey-Tripoli, Libya, 2021.

The issue of school reopening has raised several concerns; therefore, the parent's opinion is essential to consider. This study aimed to evaluate the parent's attitudes and concerns toward school reopening in the COVID-19 era. A cross-sectional survey was performed using in-person self-administered questionnaires, the data was collected in the period between January and April 2021 covering parents' concerns and attitudes toward school reopening. A total of 402 parents participated in the survey. Analysis showed that 56.7% of parents have agreed with school reopening, but 54% have raised some legitimate concerns. Importantly, there was a strong correlation between parents' opinions towards school reopening and their level of education, and their concerns about their children's safety if the school was reopened. Despite parents' concerns, it does seem that slightly over half were in favour of school reopening and would send their children to school only if the schools did apply strict precautions and restriction measures. Sharing parents' views toward school reopening with school leaders and decision-makers is important to assess the feasibility and effectiveness of return to schools and to improve existing prevention programs.

Exploratory investigation on the antibacterial effect of antimicrobial peptides of four mammalian plasmas.

Antimicrobial peptides (AMPs) are presently being revisited as promising potential antimicrobial combat agents. Acquisition of resistance to AMPs is very rare compared to conventional antibiotics as they kill microbes by direct disruption of cellular components including the microbial membrane and DNA. In this study four sources of mammalian plasma (human, bovine, caprine and ovine) were explored for presence and effectiveness of antimicrobial peptides by the spot-on-lawn method, followed by the agar well diffusion assay to confirm their antibacterial activity. This was followed by determination of their minimum inhibitory concentrations (MIC) and minimum bactericidal concentration (MBC) by the broth macrodilusion method. The MICs were compared to those produced by the antibiotics Ampicillin, Amoxicillin, Doxycycline and Metronidazole. All four plasma types exhibited antibacterial activity in their native form (plasmaN) or in presence of added pepsin (plasmap). The highest antibacterial activity was shown by ovine plasmap against Klebsiella pneumoniae (MIC at dilution of 1:128), while least activity (MIC at dilution of 1:2) was shown by bovine plasmap and ovine plasmaN against K. pneumoniae, ovine plasmaN against E. coli, and ovine plasmap against Staph. aureus. All plasma sources achieved bactericidal effect. Activity of ovine plasmaN against K. pneumoniae was higher than that due to Ampilcillin, Amoxicillin, Doxycycline or Metronidazole. The least antibacterial activity was achieved by Ampicillin against K. pneumoniae, E. coli and Bacillus subtilis. Metronidazole had no effect on any of the four bacteria tested. These results indicate that AMPs hold great promise as a valuable renewed tool in the control of pathogenic microbes.

Heat shock protein 90 inhibitor BIIB021 (CNF2024) depletes NF-kappaB and sensitizes Hodgkin's lymphoma cells for natural killer cell-mediated cytotoxicity.

PURPOSE: In Hodgkin's lymphoma, constitutive activation of NF-kappaB promotes tumor cell survival and proliferation. The molecular chaperone heat shock protein 90 (HSP90) has immune regulatory activity and supports the activation of NF-kappaB in Hodgkin's lymphoma cells. EXPERIMENTAL DESIGN: We analyzed the effect of HSP90 inhibition on viability and NF-kappaB activity in Hodgkin's lymphoma cells and the consequences for their recognition and killing through natural killer (NK) cells. RESULTS: The novel orally administrable HSP90 inhibitor BIIB021 (CNF2024) inhibited Hodgkin's lymphoma cell viability at low nanomolar concentrations in synergy with doxorubicin and gemcitabine. Annexin V/7-aminoactinomycin D binding assay revealed that BIIB021 selectively induced cell death in Hodgkin's lymphoma cells but not in lymphocytes from healthy individuals. We observed that BIIB021 inhibited the constitutive activity of NF-kappaB and this was independent of IkappaB mutations. Furthermore, we analyzed the effect of HSP90 inhibition on NK cell-mediated cytotoxicity. BIIB021 induced the expression of ligands for the activating NK cell receptor NKG2D on Hodgkin's lymphoma cells resulting in an increased susceptibility to NK cell-mediated killing. In a xenograft model of Hodgkin's lymphoma, HSP90 inhibition significantly delayed tumor growth. CONCLUSIONS: HSP90 inhibition has direct antitumor activity in Hodgkin's lymphoma in vitro and in vivo. Moreover, HSP90 inhibition may sensitize Hodgkin's lymphoma cells for NK cell-mediated killing via up-regulation of ligands engaging activating NK cell receptors.