Immunological memory articles from across Nature Portfolio

Immune imprinting can affect the response to future infection with pathogen variants. Here, Pušnik et. al. demonstrate that previous vaccination with wild-type SARS-CoV-2 vaccine hampers the formation of an immune response to mutated regions of omicron surface proteins following omicron breakthrough infection.

Prior infection or exposure to SARS-CoV-2 may influence immunogenicity and effectiveness of subsequent vaccination to new strains of virus. Here the authors show that immunogenicity of a BA.4/5 mRNA vaccine differed in recipients depending on whether they had been exposed to or infected with an earlier strain of virus.

Kratchmarov et al. identified a GATA3⁺ T_H2 population that expresses the transcription factors TCF1 and LEF1 and sustains type 2 inflammation in tissues over a human lifetime, despite chronic antigen exposure.

SARS-CoV-2 immune responses after vaccination in individuals with multiple sclerosis (MS) remain poorly understood. Here, using mass cytometry, the authors demonstrate that, following three doses of mRNA vaccine, patients with MS have distinct metabolic profiles in antigen-specific B and T cells.

Here the authors use three different mouse models to show that prior infection or mRNA vaccination can protect against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) independently of antibodies, highlighting the importance of T cell-derived interferon-γ (IFN-γ) in host defense and the need to consider this measure of protection in vaccination.

T cell- and antibody-based immunological protection are generally considered to function together, but data now show how T cells conferred by previous SARS-CoV-2 infection or two-dose vaccination can elicit heterologous protection in mice against subsequent SARS-CoV-2 infection, even in the absence of antibodies.

In this study, we developed an adenoviral-vectored vaccine that targets the spike protein of BA.5 Omicron SARS-CoV-2. When nasally delivered in mice and hamsters, the vaccine stimulated mucosal antibody production and CD8⁺ T cell responses, and demonstrated protection against several SARS-CoV-2 strains, including the antigenically distant Omicron XBB.1.5 strain. Immune cell depletion studies showed that cross-reactive memory CD8⁺ T cells contribute to the cross-protection that is conferred by nasal vaccines against respiratory infection with antigenically shifted SARS-CoV-2 Omicron strains.