Immune correlates of protection for SARS-CoV-2, Ebola and Nipah virus infection

Abstract

Correlates of protection (CoP) are biological parameters that predict a certain level of protection against an infectious disease. Well-established correlates of protection facilitate the development and licensing of vaccines by assessing protective efficacy without the need to expose clinical trial participants to the infectious agent against which the vaccine aims to protect. Despite the fact that viruses have many features in common, correlates of protection can vary considerably amongst the same virus family and even amongst a same virus depending on the infection phase that is under consideration. Moreover, the complex interplay between the various immune cell populations that interact during infection and the high degree of genetic variation of certain pathogens, renders the identification of immune correlates of protection difficult. Some emerging and re-emerging viruses of high consequence for public health such as SARS-CoV-2, Nipah virus (NiV) and Ebola virus (EBOV) are especially challenging with regards to the identification of CoP since these pathogens have been shown to dysregulate the immune response during infection. Whereas, virus neutralising antibodies and polyfunctional T-cell responses have been shown to correlate with certain levels of protection against SARS-CoV-2, EBOV and NiV, other effector mechanisms of immunity play important roles in shaping the immune response against these pathogens, which in turn might serve as alternative correlates of protection. This review describes the different components of the adaptive and innate immune system that are activated during SARS-CoV-2, EBOV and NiV infections and that may contribute to protection and virus clearance. Overall, we highlight the immune signatures that are associated with protection against these pathogens in humans and could be used as CoP.

Sustained spike-specific IgG antibodies following CoronaVac (Sinovac) vaccination in sub-Saharan Africa, but increased breakthrough infections in baseline spike-naive individuals

“…The declining levels of antibodies six months after the initial dose aligns with previously observed trends elsewhere ( 24 ). Given that this is a whole particle based vaccine, it is crucial to consider measuring immune responses to other structural targets of the virus, such as the envelope and membrane, as these have been identified to contribute to the induced immunity ( 25 – 27 ), although they were not assessed in this study.…”

Vaccine-induced SARS-CoV-2 antibody response: the comparability of S1-specific binding assays depends on epitope and isotype discrimination

“…A correlate of protection (CoP), on the other hand, is a measurable parameter that allows the prediction of immune protection in vaccinated individuals. Although spike-specific antibody titers have been proposed as a promising CoP for COVID-19, it is challenging to define which antibody titers are sufficient for immune protection ( 34 , 37 , 53 ). Several groups compared the antibody response in different ChAd/BNT vaccination cohorts using different routine binding assays ( 49 , 54 – 56 ).…”

Evolutionary, comparative, and functional analyses of STATs and regulation of the JAK-STAT pathway in lumpfish upon bacterial and poly(I:C) exposure

“…Upon activation, both STAT1 and sta t 1a form complexes with transcription factors like IRF9, resulting in the activation of interferon-stimulated gene (ISG) expression ( Lu et al., 2020 ; Tolomeo et al., 2022 ). This well-studied pathway has been extensively explored in the context of dangerous viruses such as Ebola and Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in humans as host ( Tolomeo et al., 2022 ; Escudero-Perez et al., 2023 ). These results provide important information on the conservation and variety of the JAK-STAT pathway in fish and set the stage for future studies on the functional involvement of STAT-related genes in controlling important biological processes.…”