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WASHINGTON: Antibodies in serum samples collected from patients infected with SARS-CoV during the 2003 outbreak effectively neutralized SARS-CoV-2 infection in cultured cells, according to a new study.
The study was published in the journal – Science Advances.
The authors also report that surprisingly, mice and rabbits immunized with a receptor-binding domain (RBD) from a strain of SARS-CoV that infects the Himalayan palm civet elicited stronger antibody responses against SARS-CoV- 2 than animals immunized with an RBD. of a human strain of SARS-CoV.
The authors suggest that their findings may inform strategies for developing universal vaccines against emerging and future coronaviruses. Yuanmei Zhu and colleagues analyzed 20 convalescent serum samples from SARS-CoV-infected patients, determining cross-reactivity for protein antigens derived from four regions of the SARS-CoV-2 peak protein, including the ectodomain (S), subunit. S1, RBD and S2 subunit. While all serum samples reacted strongly with proteins S and S2, they reacted weaker with proteins S1 and RBD. A separate test using a single-cycle infection assay determined that convalescent SARS-CoV sera effectively prevented SARS-CoV and SARS-CoV-2 pseudoviruses (which cannot produce viral surface proteins on their own) from infecting. cells, although they inhibited SARS-CoV-2 activity less efficiently.
The researchers verified their findings in animals and specifically characterized RBD’s ability to mediate cross-reactivity in mice, since RBD is the least conserved of the spike protein sites between the two viruses. They found that SARS-CoV anti-RBD serum cross-reacted with SARS-CoV-2, suggesting that a key antigenic component is genetically conserved at the RBD sites of the two viruses.
Zhu et al. note that although an antibody-dependent enhancement was not observed in this study (when binding of a virus to certain antibodies facilitates its entry into host cells), the effect must be addressed during vaccine development.
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The study was published in the journal – Science Advances.
The authors also report that surprisingly, mice and rabbits immunized with a receptor-binding domain (RBD) from a strain of SARS-CoV that infects the Himalayan palm civet elicited stronger antibody responses against SARS-CoV- 2 than animals immunized with an RBD. of a human strain of SARS-CoV.
The authors suggest that their findings may inform strategies for developing universal vaccines against emerging and future coronaviruses. Yuanmei Zhu and colleagues analyzed 20 convalescent serum samples from SARS-CoV-infected patients, determining cross-reactivity for protein antigens derived from four regions of the SARS-CoV-2 peak protein, including the ectodomain (S), subunit. S1, RBD and S2 subunit. While all serum samples reacted strongly with proteins S and S2, they reacted weaker with proteins S1 and RBD. A separate test using a single-cycle infection assay determined that convalescent SARS-CoV sera effectively prevented SARS-CoV and SARS-CoV-2 pseudoviruses (which cannot produce viral surface proteins on their own) from infecting. cells, although they inhibited SARS-CoV-2 activity less efficiently.
The researchers verified their findings in animals and specifically characterized RBD’s ability to mediate cross-reactivity in mice, since RBD is the least conserved of the spike protein sites between the two viruses. They found that SARS-CoV anti-RBD serum cross-reacted with SARS-CoV-2, suggesting that a key antigenic component is genetically conserved at the RBD sites of the two viruses.
Zhu et al. note that although an antibody-dependent enhancement was not observed in this study (when binding of a virus to certain antibodies facilitates its entry into host cells), the effect must be addressed during vaccine development.
