Evidence map›Paper›PMID 42265879›Full record

ArticleInfluenza and other respiratory viruses2026

Comparable Neutralizing Antibody Responses Following JN.1 and KP.2-Based COVID-19 Vaccination Suggest Limited Added Value of Minor Strain Updates: A Multicentre Immunogenicity Study.

Lena Pracher, Mastura Wahedi, Anselm Jorda, Michelle M Fukumitsu, Marlene Prager, Dragan Copic, Jasmin Zessner-Spitzenberg, Edith Lackner, Theresa Pecho, Katie Sharff and 5 more

Abstract readMulticenter Study
PubMed Full text at PMC Publisher
In one paragraph

Article in Influenza and other respiratory viruses, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

15 authors.

Lena PracherDepartment of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.
Mastura WahediDepartment of Occupational Health, Oregon Health and Science University, Portland, Oregon, USA.
Anselm JordaDepartment of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.ORCID https://orcid.org/0000-0001-5500-5878
Michelle M FukumitsuDepartment of Occupational Health, Oregon Health and Science University, Portland, Oregon, USA.
Marlene PragerDepartment of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.
Dragan CopicDivision of Nephrology and Dialysis, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria.
Jasmin Zessner-SpitzenbergDivision of Gastroenterology and Hepatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria.
Edith LacknerDepartment of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.
Theresa PechoDepartment of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.
Katie SharffSanofi Vaccines, Waltham, Massachusetts, USA.
Justin IampietroSanofi Vaccines, Waltham, Massachusetts, USA.
Joshua NealonSanofi Vaccines, Waltham, Massachusetts, USA.
William B MesserDivision of Infectious Diseases, Department of Medicine, Oregon Health and Science University, Portland, Oregon, USA.
Markus ZeitlingerDepartment of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.
Marcel E CurlinDepartment of Occupational Health, Oregon Health and Science University, Portland, Oregon, USA.

Funding

Sanofi VBA0006
6 · The paper itself

Abstract

objectivesCOVID-19 vaccines are periodically updated to address SARS-CoV-2 evolution. Whether minor antigen changes provide immunological or even clinical benefit remains unclear. This study compared neutralizing antibody responses following vaccination with the JN.1-based or KP.2-based 2024/25 Pfizer-BioNTech mRNA vaccine.

methodsAdults aged 18-64 years who received the JN.1 vaccine in Austria, or the KP.2 vaccine in the United States were enrolled. A single blood sample was obtained within 120 days post-vaccination. Pseudovirus neutralization assays against SARS-CoV-2 variants XBB.1.5, JN.1, KP.2, KP3.1.1, XEC and LP.8.1 were performed. Geometric mean titre (GMT) ratios were analysed using t-tests and multivariable regression adjusted for age, sex, vaccination intervals, and prior infection.

resultsAmong 191 participants (78 JN.1, 113 KP.2), GMTs (95% CI) for XBB.1.5 variant were higher in the JN.1 cohort (3498 [2535-4826]) than in the KP.2 cohort (1901 [1386-2607]), GMT ratio 1.84 (1.16-2.92). For the JN.1 variant, GMTs were 1122 (819-1538) in the JN.1 cohort and 695 (510-948) in the KP.2 cohort (GMT ratio: 1.61 [1.03-2.54]). GMTs for other variants did not differ significantly. After adjustment, only the XBB.1.5 difference remained significant (p = 0.04).

conclusionsComparable neutralizing responses across JN.1 lineage variants suggest that annual COVID-19 strain updates targeting variants with small differences within the same antigenic cluster may have limited impact on vaccine-induced protection. These findings may inform future public health policy and regulatory decision-making for COVID-19 vaccines.

Indexed as

Antibodies, NeutralizingAntibodies, ViralCOVID-19COVID-19 VaccinesImmunogenicity, VaccineSARS-CoV-2AdolescentAdultAustriaFemaleHumansMaleMiddle AgedUnited StatesVaccinationYoung AdultAntibodies, NeutralizingAntibodies, ViralCOVID-19 Vaccines

Identifiers

PMID42265879
PMCPMC13250256

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.