Journal: medRxiv

Article Title: In Vivo Blood Kinetics and Transcript Integrity of Three mRNA–Lipid Nanoparticle Vaccines in Humans

doi: 10.64898/2026.03.13.26348310

Figure Lengend Snippet: A) Three cohort of human subjects were recruited who received either Moderna, Pfizer, or mRNA-RBD vaccination. B) Serial blood samples were collected before and after vaccination and analyzed by ddPCR, mass spectrometry and ELISA to quantify vaccine mRNA, ionizable lipid, and antibody response (anti-PEG and anti-spike), respectively.

Article Snippet: Intact mRNA AUC was compared between Moderna and Pfizer ( ) using the nonparametric Mann−Whitney U test in GraphPad Prism 10.

Techniques: Mass Spectrometry, Enzyme-linked Immunosorbent Assay

Journal: medRxiv

Article Title: In Vivo Blood Kinetics and Transcript Integrity of Three mRNA–Lipid Nanoparticle Vaccines in Humans

doi: 10.64898/2026.03.13.26348310

Figure Lengend Snippet: Comparison of in vivo vaccine mRNA kinetics in human blood following three types of SARS-CoV-2 mRNA vaccination (Moderna, Pfizer, or mRNA-RBD). (A–C) Longitudinal vaccine mRNA concentrations (copies µL −1 ) in human blood from seven cohorts receiving either (A) Moderna bivalent ancestral + BA.1, bivalent ancestral + BA.5, or monovalent XBB.1.5; (B) Pfizer; or (C) mRNA-RBD at 10, 20, or 50 µg doses. The lower limit of quantification (LLOQ; dashed line) was determined from linear standard curves (Figure S1D–G). In panel A, two the lower limits of quantifications (LLOQs) are shown: 0.4 copies µL −1 for Moderna XBB.1.5 (dark blue dashed line) and 0.93 copies µL −1 for Moderna bivalent vaccines (light blue dashed line). Undetected samples (0 copies μL −1 ) were plotted with open symbols. (D–G) Comparison of (D) mRNA concentration at day 6–7 post-vaccination, (E) post-peak mRNA decay rates, (F) post-peak area under the curve (AUC) of mRNA kinetics in blood, and (G) averaged mRNA kinetics across donors among the three vaccine types. In (D–F), each dot represents one participant, and the horizontal line indicates the median. In (G), averaged mRNA kinetics are shown as mean predictions from the best-fit linear model, with shaded regions indicating the 95% confidence interval bounds. Statistical analysis was performed using the nonparametric Kruskal–Wallis test with Dunn’s multiple comparisons in (D, F) and the likelihood ratio test in (E).

Article Snippet: Intact mRNA AUC was compared between Moderna and Pfizer ( ) using the nonparametric Mann−Whitney U test in GraphPad Prism 10.

Techniques: Comparison, In Vivo, Vaccines, Concentration Assay

Journal: medRxiv

Article Title: In Vivo Blood Kinetics and Transcript Integrity of Three mRNA–Lipid Nanoparticle Vaccines in Humans

doi: 10.64898/2026.03.13.26348310

Figure Lengend Snippet: Comparison of in vivo ionizable lipid kinetics in human blood following Moderna, Pfizer, or mRNA-RBD vaccination. (A–C) Longitudinal ionizable lipid concentrations (ng mL −1 ) in human blood from seven cohorts who received either (A) Moderna bivalent ancestral + BA.1, bivalent ancestral + BA.5, or monovalent XBB.1.5 (formulated with SM-102); (B) Pfizer (formulated with ALC-0315); or (C) mRNA-RBD (formulated with Dlin-MC3-DMA) vaccination at 10, 20, or 50 µg doses. (D–G) Comparison of (D) ionizable lipid concentration at day 6–7 post-vaccination, (E) post-peak ionizable lipid decay rates, (F) post-peak AUC of ionizable lipid kinetics in blood, and (G) averaged ionizable lipid kinetics across donors among the three vaccine types. In (D–F), each dot represents one participant, and the horizontal line indicates the median. In (G), averaged ionizable lipid kinetics are shown as mean predictions from the best-fit linear model, with shaded regions indicating the 95% confidence interval bounds. Statistical analysis was performed using the nonparametric Kruskal–Wallis test with Dunn’s multiple comparisons in (D, F) and the likelihood ratio test in (E).

Article Snippet: Intact mRNA AUC was compared between Moderna and Pfizer ( ) using the nonparametric Mann−Whitney U test in GraphPad Prism 10.

Techniques: Comparison, In Vivo, Concentration Assay

Journal: medRxiv

Article Title: In Vivo Blood Kinetics and Transcript Integrity of Three mRNA–Lipid Nanoparticle Vaccines in Humans

doi: 10.64898/2026.03.13.26348310

Figure Lengend Snippet: Comparison of in vivo vaccine mRNA integrity in human blood between Moderna and Pfizer vaccines. (A,B) Longitudinal vaccine mRNA integrity in human blood from four cohorts who received either (A) Moderna bivalent ancestral + BA.1, bivalent ancestral + BA.5, or monovalent XBB.1.5 or (B) Pfizer vaccination. (C,D) Longitudinal intact vaccine mRNA concentration (copies µL −1 ) in human blood from the four cohorts. The LLOQ (shown as a dashed line) was determined based on the linear standard curves of vaccine mRNA (Figure S1D–F). In panel C, two LLOQs are shown: 0.4 copies µL −1 for Moderna XBB.1.5 (dark blue dashed line) and 0.93 copies µL −1 for Moderna bivalent vaccines (light blue dashed line). Undetected samples (0 copies μL −1 ) were plotted with open symbols. (E–G) Comparison of (E) post-peak intact mRNA decay rates, (F) post-peak AUC of intact mRNA kinetics in blood, and (G) averaged intact mRNA kinetics across donors between the two vaccine types. In (E,F), each dot represents one participant, and the horizontal line indicates the median. In (G), averaged intact mRNA kinetics are shown as mean predictions from the best-fit linear model, with shaded regions indicating the 95% confidence interval bounds. Statistical analysis was performed using the nonparametric Mann−Whitney U test in (F) and the likelihood ratio test in (E).

Article Snippet: Intact mRNA AUC was compared between Moderna and Pfizer ( ) using the nonparametric Mann−Whitney U test in GraphPad Prism 10.

Techniques: Comparison, In Vivo, Vaccines, Concentration Assay, MANN-WHITNEY

Journal: medRxiv

Article Title: In Vivo Blood Kinetics and Transcript Integrity of Three mRNA–Lipid Nanoparticle Vaccines in Humans

doi: 10.64898/2026.03.13.26348310

Figure Lengend Snippet: Comparison of in vivo decay kinetics of vaccine mRNA and ionizable lipids in human blood following Moderna, Pfizer, or mRNA-RBD vaccination. (A) Best-fit decay slopes of total mRNA, intact mRNA, and ionizable lipids across the three vaccines. The response at the peak time point for each parameter was normalized to 100%, and the percentage change over time illustrates the decline estimated from the best-fit linear model. (B) Half-life of total mRNA, intact mRNA, and ionizable lipids from the three vaccines, shown as the mean with upper and lower bound of 95% confidence intervals calculated across multiple donors in each cohort.

Article Snippet: Intact mRNA AUC was compared between Moderna and Pfizer ( ) using the nonparametric Mann−Whitney U test in GraphPad Prism 10.

Techniques: Comparison, In Vivo, Vaccines

Journal: medRxiv

Article Title: In Vivo Blood Kinetics and Transcript Integrity of Three mRNA–Lipid Nanoparticle Vaccines in Humans

doi: 10.64898/2026.03.13.26348310

Figure Lengend Snippet: Comparison of anti-PEG antibody levels in human blood before and after Moderna, Pfizer, or mRNA-RBD vaccination. (A,B) Comparison of plasma anti-PEG IgG and IgM endpoint titers before vaccination (Pre-Vax) and after vaccination (Post-Vax) for the three vaccine types. (C,D) Cross-comparison of fold changes (Post-Vax/Pre-Vax) in anti-PEG IgG and IgM endpoint titers among the three vaccine types. In (C,D), each dot represents one participant, and the horizontal line indicates the mean. Statistical analysis was performed using the nonparametric Wilcoxon matched-pairs signed rank test in (A,B) and the nonparametric Kruskal–Wallis test with Dunn’s multiple comparisons in (C,D).

Article Snippet: Intact mRNA AUC was compared between Moderna and Pfizer ( ) using the nonparametric Mann−Whitney U test in GraphPad Prism 10.

Techniques: Comparison, Clinical Proteomics

Journal: medRxiv

Article Title: In Vivo Blood Kinetics and Transcript Integrity of Three mRNA–Lipid Nanoparticle Vaccines in Humans

doi: 10.64898/2026.03.13.26348310

Figure Lengend Snippet: In vivo degradation patterns of Moderna vaccine mRNA in human blood evaluated using ten two-primer fragments in a duplex PCR assay. (A) Schematic illustration of the ten two-primer fragments, each targeting two regions of the Moderna vaccine mRNA sequence in the duplex ddPCR assay to assess degradation patterns of vaccine mRNA. (B) Vaccine mRNA integrity in plasma from six subjects at days 1, 4, and 7 post-Moderna vaccination (three subjects received the bivalent ancestral + BA.1 vaccine and three received the bivalent ancestral + BA.5 vaccine) assessed using the ten fragments. (C) Comparison of mRNA integrity across the ten fragments in plasma samples (day 1 post-vaccination), neat Moderna vaccine, and synthetic Moderna vaccine mRNA. (D,E) Spearman correlation analysis between mRNA integrity in plasma at day 1 post-vaccination and mRNA integrity in (D) neat Moderna vaccine or (E) synthetic Moderna vaccine mRNA. (F,G) Comparison of intact mRNA decay rates across (F) the ten fragments or (G) the six subjects. (H) Best-fit decay slopes of intact mRNA across six donors, with each data point representing the average decay rate calculated from ten individual fragments. For each donor, decay rates were estimated separately for each fragment, and the mean of these ten fragment-specific rates was used to represent the donor-level decay slope. As the decay slopes of donors 2 and 5 overlap, the curve of donor 5 was plotted with higher thickness than that of donor 2 to improve readability. In (C,F), mRNA integrity (%) and decay rates in plasma samples are shown as the mean with upper and lower bound of 95% confidence intervals calculated across six donors.

Article Snippet: Intact mRNA AUC was compared between Moderna and Pfizer ( ) using the nonparametric Mann−Whitney U test in GraphPad Prism 10.

Techniques: In Vivo, Sequencing, Clinical Proteomics, Comparison