Initial results also exhibit superb efficacy of the vaccine in preventing hospitalization and severe disease in healthy individuals (7, 8)

Initial results also exhibit superb efficacy of the vaccine in preventing hospitalization and severe disease in healthy individuals (7, 8). Natural SARS-CoV-2 infection induced durable antibody response and cellular immune memory at least 8-12 months in earlier reports (9, 10), but the neutralizing antibody titers dropped to a relatively low level, especially neutralization to the VOCs (10C13). CD4+ T cell, IL-2+ CD4+ T cell, and TNF-+ CD4+ T cell reactions were significantly improved in SARS-CoV-2 recovered individuals. Our data highlighted the security and energy of SARS-CoV-2 inactivated vaccine and shown that powerful humoral and cellular immune response can be reactivated by one-dose inactivated vaccine in SARS-CoV-2 recovered individuals. Keywords: COVID-19, long-term convalescent, SARS-CoV-2 inactivated vaccine, immune responses, VOCs Intro The coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) illness, has resulted in hundreds of millions?of infections and great mortality worldwide. The improved transmission and pathogenicity of the growing numerous SARS-CoV-2 variant of issues (VOCs, Alpha, Beta, Gamma, Delta, and Omicron) further aggravate the persistence of the pandemic (1C3). Different SARS-CoV-2 vaccines are widely administered in healthy individuals worldwide to cope with the current epidemic scenario (4C6). Preliminary results also exhibit superb efficacy of the vaccine in avoiding hospitalization and severe disease in healthy individuals (7, 8). Organic SARS-CoV-2 illness induced durable antibody response and cellular immune memory space at least 8-12 weeks in previous reports (9, 10), but the neutralizing antibody titers fallen to a relatively low level, especially neutralization to the VOCs (10C13). Hence, it is important to further explore the humoral and cellular immune response of boost vaccine on convalescent individuals and investigate their capacity STAT3-IN-1 to neutralize numerous SARS-CoV-2 VOCs. Several previous studies showed the SARS-CoV-2 vaccines can perfect powerful humoral and cellular immune response in SARS-CoV-2 recovered patients and a STAT3-IN-1 single dose is DHX16 sufficient to reactivate immune STAT3-IN-1 memory space (14C17). However, most studies focused on mRNA vaccines. In addition, the patients enrolled in these studies experienced a relatively short interval (about 2-10 weeks) between symptom-onset and vaccination, and the immunological memory space of these early convalescent COVID-19 individuals was still managed at a relatively higher level (18, 19). To day, data within the security and protecting immunity of SARS-CoV-2 inactivated vaccination for long-term (more than one yr) convalescent individuals are still limited. Here, we targeted to characterize the IgG antibody against the receptor-binding website (RBD) of spike protein (anti-S-RBD IgG), as well as the neutralizing antibodies (NAbs) against the original SARS-CoV-2 (crazy type, WT) and VOCs in long-term recovered patients (approximately 16 weeks after symptom onset) following SARS-CoV-2 inactivated vaccination. Furthermore, SARS-CoV-2 RBD specific B cells response and STAT3-IN-1 antigen-specific T cells response to SARS-CoV-2 overlapping peptides were investigated. The graphic abstract including two cohorts were provided in Number S1. Evaluation of the security and protecting immunity of long-term recovered individuals boosted with SARS-CoV-2 inactivated vaccines in the real world would lay a solid foundation for medical epidemic prevention and provide a theoretical basis for vaccine optimization. Methods Study design and participants 51 SARS-CoV-2 recovered individuals (SR) who have been pre-vaccinated or experienced completed the 1st or second dose of inactivated vaccines (CoronaVac, BBIBP-CorV, or WIBP-CorV) were consented and enrolled in our study. 63 healthy subjects(HC) with completed (two doses) vaccination were enrolled as settings. All the healthy donors (without known SARS-CoV-2 illness history) were recruited based on self-reported symptom-free with bad IgG antibody and bad PCR test of nasopharyngeal swab before vaccination. The disease severity of COVID-19 recovered patients STAT3-IN-1 was defined according to the Guidelines of the Analysis and Treatment for SARS-CoV-2 issued by the Chinese National Health Committee (Version 7). All participants were without severe health conditions or immune-related diseases that may impact the vaccine response. Clinical data in the acute phase were from electronic medical records, including demographic, medical manifestation, and comorbidities. The overall incidence of adverse reactions.