As novel SARS-CoV-2 variants continue to emerge, the updated XBB.1.5 monovalent vaccines remain to be evaluated in terms of immunogenicity against live clinical isolates. We report boosting of IgG(2.1X), IgA(1.5X), and total IgG/A/M(1.7X) antibodies targeting the spike receptor-binding domain and neutralizing titers against WA1(2.2X), XBB.1.5(7.4X), EG.5.1(10.5X), and JN.1(4.7X) variants.

The authors have declared no competing interest.

This study was funded in part by NIH R01AI141549 (to FGT).

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

The details of the IRB/oversight body that provided approval or exemption for the research described are given below:

The institutional review board of Oregon Health & Science University gave ethical approval for this work.

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Yes

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes

All data produced in the present study are available upon reasonable request to the authors.