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BBIBP-CorV exerts efficient protection against SARS-CoV-2 infection. However, waning vaccine-induced humoral immune responses after two-dose vaccination have significantly undermined durable immuno-protection. In this study, we have demonstrated that although anti-spike (S) antibody responses in BBIBP-CorV vaccinees exhibited three serotypes after 6 months, including de novo sero-negative, sero-positive, and sero-decay features, S-specific interferon-γ release as well as Th1 cytokine production in CD4+ and CD8+ T cells were comparable, especially in vaccinees without detectable neutralizing antibodies. Notably, regardless of dramatic increases in humoral immunity after booster vaccination, T cell responses targeting S protein from either wild type or Omicron remained stable before and after booster vaccination in all three serotype vaccinees. No severe cases were observed even in the sero-decay group during the Omicron epidemic in Shanghai. Our results thus illustrate that unlike fluctuating humoral responses, viral-specific T cell responses are extremely stable after booster vaccination. Sustained T cell responses might be dedicated to the rapid restoration of antibody responses after booster vaccination. more...

The direct utilization of fluorescent signals to explore biological property or sensing performance has been extensively studied in recent years, whereas the employment of lanthanide ions as tracking agents for the shape memory process will be very rare. In this work, polyvinyl alcohol (PVA) has been attached by tryptophan and such polymeric host could bind well with both europium and terbium ions. However, the intra-molecular energy transfer efficiency was relatively low and the second ligand marbofloxacin has been incorporated. In this way, typical red and green emissions derived from europium and terbium ions are afforded. These findings lead to the systematic exploitation of polymer chain network with striking lanthanide luminescence and the detailed shape memory evolution can be recorded. In addition, such organic-inorganic hybrid hydrogel is valuable in metal management and the selective fluorescent responses to copper ions are evaluated. Therefore, the new composite exhibits potentials in signaling and determination of target species with biological or environmental importance. more...

Since the first report of the coronavirus disease (COVID-19) in late December 2019, the pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has now widely spread to more than 187 countries and regions. However, it is unclear whether there has been cryptic transmission before these early officially confirmed cases, we therefore retrospectively screened for the SARS-CoV-2 RNA in 1271 nasopharyngeal swab samples, as well as the prevalence of IgM, IgG, and total antibodies against SARS-CoV-2 in 357 matched serum samples collected from hospitalized patients with influenza-like illness between 1 December 2018 and 31 March 2020 in Shanghai Ruijin Hospital. The onset date of the earliest COVID-19 case in this study was 25 January 2020. Before this time point, the presence of SARS-CoV-2 was not observed, which limited the possibility that SARS-CoV-2 has already spread among the population before the large-scale outbreak. Additionally, among 6662 patients with influenza-like illness from 1 December 2017 to 31 March 2020, the overall number of patients positive for influenza and other respiratory viruses during the COVID-19 period decreased significantly when compared with that in the same period of the last two years, reflecting that public health interventions can effectively control the spread of common respiratory viruses. more...

Proton emissions from the reaction of neutrons with stainless steel at a 14.6-MeV neutron energy are measured using a multitelescope system. A 1Cr18Ni9Ti (Type 321) stainless steel is used. The double-differential cross sections (DDCS) of 16 reaction angles from 25 to 165 deg are obtained in this measurement. The energy spectra and the angular distributions of proton emissions are obtained from the DDCS. The angular distributions show a slightly energy-dependent forward-backward asymmetry. The total proton emission cross section is 229 ± 16 mb for a proton energy >2 MeV. more...