Cross-neutralization of SARS-CoV-2 BA.3.2.2 lineage by JN.1 mRNA vaccine-induced immunity.

Convergent IGHV3-53/3-66 antibodies elicited by Omicron BA.1 infection broadly neutralize emerging SARS-CoV-2 variants

Immunological imprinting shapes the cross-reactive antibody responses to the KP.2 and LP.8.1 vaccine doses

Data indicate the KP.2 mRNA vaccine generates durable, cross-reactive responses against current Omicron subvariants, however, ongoing spike evolution impacts the neutralization of emerging lineages, highlighting the need for continued viral monitoring and timely vaccine updates.

Measurement of binding antibodies to SARS-CoV-2 variants elicited by natural infection and COVID-19 vaccines in a sub-Saharan African population

Data on immune responses to COVID-19 vaccination in West and Central Africa remain limited, particularly across SARS-CoV-2 variants and vaccine platforms. Using the InVITE cohort in the Democratic Republic of Congo, Guinea, Liberia, and Mali, we evaluated anti-spike (anti-S) antibody binding to nine SARS-CoV-2 variants in 96 participants equally selected from pre-vaccination assay defined seropositive and seronegative groups. Participants received mRNA, adenovirus-vectored, or inactivated virus vaccines. Anti-S binding was measured before vaccination and two months after completion of the primary series using a Meso Scale Discovery 10-plex assay. Before vaccination, antibody binding was significantly higher against pre-Omicron variants (Ancestral, Alpha, Beta, and Delta) than Omicron variants in both seronegative (fold change [FC] 3.85, 99% CI 3.45–4.17) and seropositive (FC 3.57, 99% CI 3.33–3.84) participants. Seropositive individuals showed greater binding than seronegative individuals across all variants. Two months post-vaccination, mRNA vaccines elicited higher antibody binding than adenovirus-vectored or inactivated vaccines, whereas no significant differences were observed between adenovirus-vectored and inactivated vaccines. Antibody binding remained higher against pre-Omicron than Omicron variants across all vaccine platforms and serostatus groups. These findings provide rare data on variant-specific vaccine-elicited antibody binding responses in West and Central African populations with distinct demographic, epidemiologic, and immunologic background. Trial registration: Registration ClinicalTrials.gov: NCT05096091, Registration date: 10-26-2021, Clinical trial registry: https://clinicaltrials.gov/study/NCT05096091?term=NCT05096091rank=1#study-overview .

Durability and Breadth of Neutralizing Antibodies Against SARS-CoV-2 Variants Following XBB.1.5 Vaccination in a Multiply Exposed Cohort.

The observed waning of cross-neutralizing antibodies against emerging variants underscores the challenge of maintaining durable protection and supports the need for continued monitoring of antibody responses to guide evidence-based updates to COVID-19 vaccines.

JN.1-adapted vaccination is associated with readjustment of ancestral memory B cells toward neutralization within the JN.1 antigenic space

It is proposed that there is somatic hypermutation of existing B cell clones rather than de novo generation from naive B cells in JN.1-adapted booster vaccines and this finding indicates maturation of pre-existing, class-switched MBC rather than substantial de novo recruitment of naïve B cells.

Wuhan-ancestral multi-antigen SARS-CoV-2 virus-like particles protect against the omicron sublineage JN.1 variant.

It is shown that a Wuhan-lineage-based multi-antigen VLP vaccine can provide cross-protection against an antigenically divergent SARS-CoV-2 variant that is not fully explained by detectable serum neutralizing activity alone, suggesting the importance of integrated immune responses involving humoral, cellular, and local immune mechanisms.