Respiratory Diseases Roundup

Emerging Data on Durability, Immunogenicity, and Patient Trust

Edited by:
Kate Young

Key Highlights

  • XBB.1.5 monovalent COVID-19 vaccination was associated with antibody half-life >500 days in a small cohort.
  • In mice, mRNA vaccination generated the strongest interferon response; Ad5 showed more sustained antigen expression and stronger single-dose responses.
  • US survey: 52% reported confidence in CDC vaccine safety/effectiveness information; 48% reported being unconfident.
  • NFID survey: 45% reported receiving ≥1 respiratory vaccine since September 2025; influenza (34%) and COVID-19 (25%) were most common.

XBB.1.5 COVID-19 Vaccine Antibodies Persist1

Researchers evaluated immune responses after the 2023–2024 monovalent XBB.1.5 COVID-19 vaccine in 24 participants, focusing on durability, breadth, and magnitude of antibody responses over 6 months. The study assessed binding antibodies and neutralizing antibodies, along with memory B-cell responses relevant to longer-term immune recall. According to the report, the updated formulation was designed as a monovalent immunization targeting XBB.1.5, differing from prior bivalent vaccines that included ancestral and newer spike antigens.

The findings described antibody kinetics consistent with prolonged persistence: the antibody half-life was reported as more than 500 days (> 16 months) and was described as about 3 times longer than antibody half-lives observed after the initial 2-dose mRNA vaccine series.  Investigators also reported cross-reactive antibodies recognizing both the ancestral WA1 strain and the Omicron XBB.1.5 variant and discussed immune imprinting as a potential contributor to cross-reactivity after monovalent boosting.

Vaccine Platforms Show Context-Dependent Immunity2

In a head-to-head preclinical study, investigators compared adenovirus type 5 (Ad5), mRNA, and protein vaccines in mice, examining antigen kinetics, innate immune signaling, adaptive responses, and protection in challenge models. Antigen expression profiles differed by platform: Ad5 produced more sustained antigen expression, whereas mRNA produced higher early antigen levels that declined rapidly, and protein vaccination generated comparatively lower antigen levels. The study also assessed antigen presentation and costimulation in draining lymph nodes and reported higher MHC class I–peptide display and increased expression of select costimulatory molecules after mRNA vaccination, consistent with more robust early priming signals.

Innate signatures were also platform-specific. mRNA vaccination induced higher levels of interferon-related cytokines and broader transcriptional changes than Ad5 or protein vaccination. In adaptive comparisons, Ad5 elicited stronger responses after a single dose, but mRNA performed better under prime-boost conditions—particularly when preexisting anti-Ad5 immunity was modeled, reflecting potential constraints of vector seroprevalence. For efficacy testing, the authors used a stringent Listeria monocytogenes–OVA challenge model and reported that an mRNA prime-boost regimen conferred significantly higher protection than other regimens in that system.

Survey: Confidence in CDC Vaccine Safety Messaging3

An Annenberg Public Policy Center asked survey respondents about confidence that CDC provides trustworthy information on vaccine safety and effectiveness. Overall, 52% reported being confident (36% “somewhat,” 16% “very”), and 48% reported being unconfident (27% “not too,” 21% “not at all”). The topline also included subgroup breakouts by political identification and age. The survey, fielded November 21-24, 2025, used a nationally representative probability sample (n = 1006) drawn from an online panel, with weighting to represent US adults; the estimated design effect was 1.21.

Additional items assessed perceptions related to vaccines and autism and recognition of CDC website content. When asked which statement was closer to their view, 52% selected that studies show no link between receiving vaccines and developing autism; 30% selected that the claim “vaccines do not cause autism” is not evidence-based because studies have not ruled out the possibility; 18% were not sure. When asked which statements are currently on the CDC website, 50% responded “not sure,” while 19% selected “no vaccine–autism link” and 20% selected “link not ruled out” (with smaller proportions selecting “both” or “neither”). The topline also asked which entity respondents would be more likely to accept if the AMA and CDC disagreed on vaccine safety, with 32% saying the AMA, 24% saying the CDC, 26% saying neither, and 18% saying they were not sure.

NFID Survey: Uptake, Barriers, and Trusted Sources4

The National Foundation for Infectious Diseases (NFID) reported results from its 2025 National Survey on Respiratory Diseases, conducted in November 2025, assessing US adults’ attitudes and behaviors related to vaccination against influenza, COVID-19, respiratory syncytial virus (RSV), and pneumococcal disease. In a key topline measure, 45% of respondents reported receiving at least one respiratory vaccine since September 2025. Influenza vaccination was most frequently reported (34%), followed by COVID-19 vaccination (25%); pneumococcal (8%) and RSV (6%) vaccination were less frequently reported. The report also noted that a substantial share of respondents described guidance around respiratory vaccination as unclear or neither clear nor unclear (44%).

The NFID also summarized reported barriers to vaccination across products. Among adults who had not received influenza vaccine that season, common reasons included concerns about side effects (16%) and believing they “never get sick” (13%); for COVID-19 vaccination, concerns about side effects (20%) and lack of a clinician recommendation (12%) were among reported barriers. For pneumococcal and RSV vaccination, lack of a clinician recommendation was also a frequently cited barrier (17% and 18%, respectively). Regarding trusted information sources, 44% selected health care professionals as the most trusted source for vaccine information and 13% selected CDC; NFID highlighted generational differences, including higher reliance on social media among younger adults.

References

  1. Suthar MS, Moreno A, Wrammert J, et al. The XBB.1.5 COVID-19 vaccine elicits a durable antibody response to ancestral and XBB.1.5 SARS-CoV-2 spike proteins. Sci Transl Med. 2025;17:eadu8067. doi:10.1126/scitranslmed.adu8067.
  2. Awakoaiye B, Li S, Sanchez S, et al. Comparative analysis of adenovirus, mRNA, and protein vaccines reveals context-dependent immunogenicity and efficacy. JCI Insight. 2025;10(21):e198069. doi:10.1172/jci.insight.198069.
  3. Topline CDC Vaccine Safety and Confidence Survey Results. https://www.annenbergpublicpolicycenter.org/wp-content/uploads/omcdc-do03-topline-cdcvaxsafety.pdf. Published November 2025. Accessed December 30, 2025.
  4. 2025 National Survey on Respiratory Diseases: U.S. Adult Vaccine Uptake and Attitudes. https://www.nfid.org/resource/2025-national-survey-on-respiratory-diseases/. Published November 2025. Accessed December 30, 2025.