key: cord-0888908-xo8caok5 authors: Liu, Q.; Xiong, Q.; Mei, F.; Ma, C.; Zhang, Z.; Hu, B.; Xu, J.; Jiang, Y.; Zhan, F.; Chen, X.; Guo, M.; Wang, X.; Fang, Y.; Shen, S.; Liu, Y.; Liu, F.; Zhou, L.; Xu, K.; Ke, C.; Deng, F.; Cai, K.; Yan, H.; Chen, Y.; Lan, K. title: Antibody neutralization to SARS-CoV-2 and variants after one year in Wuhan date: 2021-06-21 journal: nan DOI: 10.1101/2021.06.16.21258673 sha: eb56320be03a92c3e85daae80c66a9c7a203b25d doc_id: 888908 cord_uid: xo8caok5 Most COVID-19 patients can build effective humoral immunity against SARS-CoV-2 after recovery . However, it remains unknown how long the protection can maintain and how efficiently it can protect people from the reinfection of the emerging SARS-CoV-2 variants. Here we evaluated the sera from 248 COVID-19 convalescents around one year post-infection in Wuhan, the earliest epicenter of SARS-CoV-2. We demonstrated that the SARS-CoV-2 immunoglobulin G (IgG) maintains at a high level and potently neutralizes the infection of the original strain (WT) and the B.1.1.7 variant in most patients. However, they showed varying degrees of efficacy reduction against the other variants of concern (P.1, B.1.525, and especially B.1.351) in a patient-specific manner. Mutations in RBD including K417N, E484K, and E484Q/L452R (B.1.617) remarkably impair the neutralizing activity of the convalescents' sera. Encouragingly, we found that a small fraction of patients' sera showed broad neutralization potency to multiple variants and mutants, suggesting the existence of broadly neutralizing antibodies recognizing the epitopes beyond the mutation sites. Our results suggest that the SARS-CoV-2 vaccination effectiveness relies more on the timely re-administration of the epitope-updated vaccine than the durability of the neutralizing antibodies. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 21, 2021. ; https://doi.org/10.1101/2021.06.16.21258673 doi: medRxiv preprint Wuhan is the first known epicenter of the SARS-CoV-2 outbreak. Almost all 53 patients in this city were infected by the original strain before the city reopen and the 54 epidemic here had been well controlled thereafter before the emergence of 55 variants(14). In this study, sera from convalescents infected around one year ago in 56 Wuhan were collected to investigate the SARS-CoV-2 antibody durability and the (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (5/248) tested positive for anti-SARS-CoV-2 IgM (Table S1 ). Conventional ELISA 76 assays were then conducted to determine the anti-RBD IgG level and the competitive 77 ability of ACE2 to RBD-binding of the sera. As we set OD450=0.31 (the mean 78 OD450 value + 3 SD of uninfected people's sera) as the cut-off value, 91 % (225/248) 79 tested positive for anti-SARS-CoV-2-RBD IgG (Fig. 1A) . Our results also showed 80 that the competitive ability is highly consistent with the anti-RBD IgG level ( Fig. 81 1A-E, Table S1), indicating most RBD-targeting antibodies in the patients can 82 interfere with the interaction between ACE2 and RBD. However, the anti-RBD IgG 83 level and the neutralizing activity of the sera showed no statistically significant 84 difference in patients with different severity (Fig.1a-b) , gender ( Fig.1c-d) , and age 85 (Fig. 1e) . 86 The neutralizing activities of the sera were tested with SARS-CoV-2 pseudovirus 87 (WT-D614G) produced based on a replication-deficient VSV pseudotyping system 88 (VSV-dG-Luc) and a BHK-21 cell line stably expressing hACE2 (BHK-21-hACE2). (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 21, 2021. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. one mutation (N501Y) in the RBD region, a mutation without prominent immune 122 escape effect(12, 16) (Fig. 2e) . These results showed that the immune escape ability 123 of the variants can be largely attributed to the mutations in the RBD region. among the variants of concern, especially mutations on E484 and K417. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. showing high, medium, and low neutralizing activities in Fig. 1f , respectively. The 141 SARS-CoV-2 nucleocapsid (N) protein immunofluorescence assay showed consistent 142 results with the pseudovirus neutralization assay (Fig. 3a) . 143 We further verified the neutralizing activity of two groups of patients in Fig. 2 (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 21, 2021. Firstly, we report that the effective neutralizing antibodies against SARS-CoV-2 172 could last at least one year in most COVID-19 convalescents, while no statistical 173 significance was observed among different severity, gender, or age (Fig. 1a-e) . These 174 results indicate that most people including asymptomatic and elderly patients could 175 build and maintain effective anti-SARS-CoV-2 humoral immunity, with a few 176 exceptions in each group for unknown reasons (Fig. 1) . We speculate this phenotype 177 might be attributed to the individual immune difference that deserves further study. Another particular concern is the cross-variant protective efficacy of the 179 anti-SARS-CoV-2 humoral immunity. Our study provides additional evidence that 1, B.1.525, and B.1.351 (Fig. 2b) . B.1.351 183 displayed the most prominent immune escape ability among these tested variants, 184 All rights reserved. No reuse allowed without permission. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 21, 2021. ; https://doi.org/10.1101/2021.06.16.21258673 doi: medRxiv preprint consisting with the previous reports (12, 13, 18) . Encouragingly, sera from a few 185 individuals showed resistance to all tested variants (Fig. 2c) , indicating the presence 186 of effective and broadly neutralizing antibodies. It brings hope for the identification of 187 ideal broad neutralization epitopes essential for the development of antibody therapy 188 and next-generation vaccines. 189 We next sought to characterize the critical restudies that contribute to the (Fig. 2f) . 202 We do acknowledge some limitations of our studies. First, we did not determine (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. were done using GraphPad Prism 7. Differences between two independent samples 321 were evaluated by two-tailed Mann-Whitney U-tests, and P < 0.05 is considered 322 statistically significant. Differences between two related samples were evaluated by 323 paired two-tailed t-tests. Data availability 325 All data are available in the manuscript or extended data. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. The copyright holder for this preprint this version posted June 21, 2021. ; https://doi.org/10.1101/2021.06.16.21258673 doi: medRxiv preprint 1 escape from neutralizing antibodies Post-lockdown SARS-CoV-2 nucleic 414 acid screening in nearly ten million residents of Wuhan, China Acquisition of the L452R mutation in the ACE2-binding interface of 419 Spike protein triggers recent massive expansion of SARS-Cov-2 variants. bioRxiv : the preprint 420 server for biology Evidence of escape of SARS-CoV-2 variant B.1.351 from natural and 428 vaccine-induced sera Seasonal coronavirus protective immunity is short-lasting Susceptibility of Circulating SARS-CoV-2 Variants to Neutralization England journal of medicine Neutralization of N501Y mutant SARS-CoV-2 by BNT162b2 vaccine-elicited sera Neutralization of SARS-CoV spike 69/70 deletion, E484K and N501Y variants by BNT162b2 vaccine-elicited sera Comparison of vesicular stomatitis virus pseudotyped with the S proteins from a porcine and 447 a human coronavirus Quantification of SARS-CoV-2 neutralizing 451 antibody by a pseudotyped virus-based assay A note on some points of calculation method of LD50 by Reed and Muench Competing interests 347 The authors declare no competing interests. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.The copyright holder for this preprint this version posted June 21, 2021. ; https://doi.org/10.1101/2021.06.16.21258673 doi: medRxiv preprint All rights reserved. No reuse allowed without permission.(which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.The copyright holder for this preprint this version posted June 21, 2021. ; https://doi.org/10.1101/2021.06.16.21258673 doi: medRxiv preprint