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Adv Sci (Weinh) ; 9(11): e2105378, 2022 04.
Article in English | MEDLINE | ID: covidwho-1680239


The SARS-CoV-2 Delta (B.1.617.2) strain is a variant of concern (VOC) that has become the dominant strain worldwide in 2021. Its transmission capacity is approximately twice that of the original strain, with a shorter incubation period and higher viral load during infection. Importantly, the breakthrough infections of the Delta variant have continued to emerge in the first-generation vaccine recipients. There is thus an urgent need to develop a novel vaccine with SARS-CoV-2 variants as the major target. Here, receptor binding domain (RBD)-conjugated nanoparticle vaccines targeting the Delta variant, as well as the early and Beta/Gamma strains, are developed. Under both a single-dose and a prime-boost strategy, these RBD-conjugated nanoparticle vaccines induce the abundant neutralizing antibodies (NAbs) and significantly protect hACE2 mice from infection by the authentic SARS-CoV-2 Delta strain, as well as the early and Beta strains. Furthermore, the elicitation of the robust production of broader cross-protective NAbs against almost all the notable SARS-CoV-2 variants including the Omicron variant in rhesus macaques by the third re-boost with trivalent vaccines is found. These results suggest that RBD-based monovalent or multivalent nanoparticle vaccines provide a promising second-generation vaccine strategy for SARS-CoV-2 variants.

COVID-19 , Nanoparticles , Animals , Broadly Neutralizing Antibodies , COVID-19/prevention & control , Macaca mulatta/metabolism , Mice , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Vaccines, Conjugate
Cell Rep ; 38(3): 110256, 2022 01 18.
Article in English | MEDLINE | ID: covidwho-1588136


Inoculation against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is ongoing worldwide. However, the emergence of SARS-CoV-2 variants could cause immune evasion. We developed a bivalent nanoparticle vaccine that displays the receptor binding domains (RBDs) of the D614G and B.1.351 strains. With a prime-boost or a single-dose strategy, this vaccine elicits a robust neutralizing antibody and full protection against infection with the authentic D614G or B.1.351 strain in human angiotensin-converting enzyme 2 transgene mice. Interestingly, 8 months after inoculation with the D614G-specific vaccine, a new boost with this bivalent vaccine potently elicits cross-neutralizing antibodies for SARS-CoV-2 variants in rhesus macaques. We suggest that the D614G/B.1.351 bivalent vaccine could be used as an initial single dose or a sequential enforcement dose to prevent infection with SARS-CoV-2 and its variants.

COVID-19/prevention & control , Cross Protection , SARS-CoV-2/immunology , Vaccines, Combined/therapeutic use , Animals , CHO Cells , COVID-19 Vaccines/chemical synthesis , COVID-19 Vaccines/immunology , COVID-19 Vaccines/therapeutic use , Chlorocebus aethiops , Cricetulus , Cross Protection/immunology , Female , HEK293 Cells , Humans , Macaca mulatta , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Transgenic , Nanoparticles , Vaccination/methods , Vaccines, Combined/chemical synthesis , Vaccines, Combined/immunology , Vero Cells
Chinese J. Lab. Med. ; 3(43): 230-233, 20200311.
Article in Chinese | WHO COVID, ELSEVIER | ID: covidwho-769462


Objective: To investigate the diagnostic value of immunoglobulin M (IgM) and immunoglobulin G(IgG) antibodies to 2019 Novel Coronavirus (2019-nCoV) in 2019-nCoV infection. Methods: This is a retrospective study. Serum samples were collected from 284 patients including outpatients and inpatients in the Renmin Hospital of Wuhan University from January 20 to February 17 in 2020. Among them 205 cases were 2019-nCoV infected patients, including 186 cases confirmed with nucleic acid test and 19 cases diagnosed by clinical symptoms and CT characteristics according to "the New Coronavirus Pneumonia Control Protocol (5th edition)". A total of 79 subjects with other diseases but negative to 2019-nCoV infection were recruited as control group. Serum IgM and IgG antibodies to 2019-nCoV were measured with fully automated immunoassay technology for all subjects. Statistical significance between 2019-nCoV antibodies test and 2019-nCoV nucleic acid test was determined using the χ 2tests. Results: The sensitivity of serum IgM and IgG antibodies to 2019-nCoV were 70.24%(144/205) and 96.10%(197/205) respectively and the specificity were 96.20%(76/79) and 92.41%(73/79) respectively. The positive and negative predictive values of 2019-nCoV antibodies were 95.63%(197/206) and 91.03% (71/78) respectively, and the positive and negative predictive values of 2019-nCoV nucleic acid test were 100%(186/186) and 80.61%(79/98) respectively. The total coincidence rate of diagnosing 2019-nCoV infection between antibody tests and nucleic acid test for 2019-nCoV were 88.03%(250/284). Conclusion: Joint detection of serum IgM and IgG antibodies to 2019-nCoV is an effective screening and diagnostic indicators for 2019-nCoV infection, and an effective complement to the false negative results to nucleic acid test.