How does hybrid immunity form a humoral immune response to SARS-CoV-2?

In a recent study posted on medRxiv* Preprint server, researchers have shown that hybrid severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunity broadens the effective humoral sign of SARS-CoV-2 vaccination.

..study: Hybrid immunity expands the functional humoral footprint of both mRNA and vector-based SARS-CoV-2 vaccines.. Image credit: vitstudio / Shutterstock

Background

The SARS-CoV-2 pandemic has brought breakthroughs in vaccine development and has led to the screening and approval of various global vaccine platforms with great expectations for the containment of the pandemic. However, the weakened immunity associated with increased breakthrough infections in vaccinated individuals and the emergence of a Variant of Concern (VOC) for SARS-CoV-2 are beginning to emphasize opportunities to enhance the vaccine platform and administration. ..

A breakthrough reduction in the risk of infections and illnesses in those vaccinated with SARS-CoV-2, also known as hybrid immunity, is the effectiveness of the real-world CoV disease 2019 (COVID-19) vaccine. It is emphasized by sex. Hybrid immunity suggests the potential for stronger or unique immunity prepared by infection and may provide better protection from COVID-19. COVID-19 protection and wise booster vaccination and next-generation vaccine development against emerging viral VOCs by identifying platform-specific immune programming variations and how hybrid immunization can alter these. Can characterize the immunological correlation of.

About research

The current study aimed to determine if hybrid immunity could affect a functional humoral immune response to SARS-CoV-2 other than enhanced. T cells With immunity Neutralizing antibody After vaccination with Modernam RNA1273 and Pfizer / BNT162b2 messenger ribonucleic acid (mRNA) -based, ChadOx1 / AZ1222 and Ad26.COV2.S vector-based COVID-19 vaccines.

The team used one of four existing SARS-CoV-2 vaccines to examine serum samples from individuals with and without a history of fully vaccinated COVID-19. Subjects receive two doses of BNT162b2 (Pfizer) or mRNA-1273 (Moderna) mRNA vaccine, one dose of human adenovirus type 26 (Ad26) vector Ad26.COV2.S (Janssen) vaccine, or ChAdOx vector. Was inoculated twice. Vaccine AZ1222 (AstraZeneca). Blood samples were collected on average 8, 8, 34, and 7 days after the final dose of the Pfizer, Moderna, Janssen, and AstraZeneca vaccines, respectively, with the peak immunogenicity time stamps specified for each vaccine.

Results and conclusions

The study results showed that each COVID-19 vaccination under test showed distinct functional humoral immune properties in the context of hybrid or naive immunity. The different inflammatory signals evoked at the moment of vaccination were probably associated with the unique antibody function profile produced by each vaccine. A well-defined antibody function profile directs specific class-switched recombination and fragment crystallization (Fc) -glycosylation patterns in helper T-cell and B-cell reactions. They collectively form the overall Fc receptor (FcR) attachment and effector properties of the antibody’s vaccine-induced polyclonal colonies.

The authors also show that hybrid immunity also affects antibody effector activity, dramatically enhancing antibody response and FcR adhesion after administration of a single vector vaccine, and tends to further increase concentration and function after the second administration of AZD1222. I found that there is. The IgA and IgG titers of the SARS-CoV-2 spike (S) subunit 2 (S2) -specific mRNA vaccine were significantly increased as a result of hybrid immunization, indicating a preferential increase in immunity to the conserved region of S. Is antigenThe pattern of IgG1 titers only increases with the second dose of mRNA. In contrast, ADNP was significantly elevated after the first and second doses of mRNA vaccination in patients with hybrid immunity.

Furthermore, after considering demographics, S2-specific FcR attachment was preferentially enhanced within mRNA vaccinated individuals with hybrid immunity. Indeed, AZD1222 vaccinated people also showed this characteristic. The structural sustainability of the S2 domain, as well as the cross-reactivity and neutralizing capacity of S2 antibodies, may mitigate the effects of sequence-altering mutations. As a result, the vaccine may be more effective against the common cold CoV and new VOCs that occur seasonally.

Overall, research data highlight the impact of immune dominance of the S1 domain in the context of natural SARS-CoV-2 immunity. The SARS-CoV-2 S1 domain was substantially variable in the evolution of the virus. This study further points to the importance of spontaneous infection in overcoming the S1 immune predominance and inducing immunity to the S2 region of the SARS-CoV-2S2 domain, which is more conserved among VOCs.

*Important Notices

medRxiv Publish preliminary scientific reports that should not be considered definitive as they have not been peer-reviewed, guide clinical practice / health-related behaviors, and should not be treated as established information.