Phase 3 Study Assessing Lot-to-lot Consistency of RSVPreF3 Vaccine and its Immune Response, Safety, and Reactogenicity When Co-administered with FLU-D-QIV.

BACKGROUND: A single-dose investigational respiratory syncytial virus (RSV) vaccine, RSV prefusion protein F3 (RSVPreF3), was co-administered with a single-dose quadrivalent influenza vaccine (FLU-D-QIV) in a phase 3, randomized, controlled, multicenter study in healthy, non-pregnant women aged 18-49 years. METHODS: The study was observer-blind to evaluate the lot-to-lot consistency of RSVPreF3, and single-blind to evaluate the immune response, safety, and reactogenicity of RSVPreF3 co-administered with FLU-D-QIV. RESULTS: A total of 1415 participants were included in the per-protocol set. There was a robust immune response at day 31 across each of the 3 RSVPreF3 vaccine lots; adjusted geometric mean concentration ratios (95% confidence interval [CI]) were 1.01 (0.91, 1.12), 0.93 (0.84, 1.03), and 0.92 (0.83, 1.02) for RSV1/RSV2, RSV1/RSV3, and RSV2/RSV3, respectively. For FLU-D-QIV co-administered with RSVPreF3, versus FLU-D-QIV alone at day 31, noninferiority was satisfied for 3 of 4 strains assessed, with the lower limit of the 95% CI for geometric mean ratio >0.67. CONCLUSIONS: Immunogenic consistency was demonstrated for 3 separate lots of RSVPreF3. Immunogenic noninferiority was demonstrated when comparing FLU-D-QIV administered alone, versus co-administered with RSVPreF3, for 3 strains of FLU-D-QIV. Co-administration was well tolerated, and both vaccines had clinically acceptable safety and reactogenicity profiles. CLINICAL TRIALS REGISTRATION: NCT05045144; EudraCT, 2021-000357-26.

This was a phase 3 study that compared antibodies against respiratory syncytial virus (or RSV for short) between women who were given 3 different production batches of RSV prefusion protein F3 (known as RSVPreF3) vaccine. The study also compared the antibodies between women who received either an RSV vaccine together with a flu vaccine (known as FLU-D-QIV), or a flu vaccine alone. The flu vaccine contained 4 different strains of flu virus. The study involved 1415 healthy, non-pregnant women aged 18­49 years. The antibodies checked after 31 days showed strong immune responses for all 3 RSV vaccine production batches, and similar immune responses between each of the 3 RSV vaccine production batches. The immune response of 3 of the 4 flu strains was not less when the flu vaccine was given together with the RSV vaccine than the immune response when flu vaccine was given alone and both vaccines were well tolerated.

Safety and Immunogenicity of Respiratory Syncytial Virus Prefusion Maternal Vaccine Coadministered With Diphtheria-Tetanus-Pertussis Vaccine: A Phase 2 Study.

BACKGROUND: Respiratory syncytial virus (RSV) fusion protein stabilized in the prefusion conformation (RSVPreF3) was under investigation as a maternal vaccine. METHODS: This phase 2, randomized, placebo-controlled, single-dose, multicenter study enrolled healthy, nonpregnant women, randomized 1:1:1:1:1 to 5 parallel groups studying RSVPreF3 (60 or 120 µg) coadministered with diphtheria, tetanus, and acellular pertussis vaccine (dTpa) or placebo, and dTpa coadministered with placebo. Safety and humoral immune responses were assessed. An extension phase also assessed a RSVPreF3 120 µg vaccination 12-18 months after first vaccination. RESULTS: The safety profile of RSVPreF3 was unaffected by dose or dTpa coadministration. Solicited and unsolicited adverse events (AEs) were evenly distributed across study groups. Injection-site pain was higher following the second vaccination versus the first vaccination. Medically attended AEs were rare (<5% overall). Both RSVPreF3 dose levels (alone and with dTpa) were immunogenic, increasing levels of RSV-A neutralizing antibody ≥8-fold and anti-RSVPreF3 IgG antibody ≥11-fold at 1 month postvaccination, which persisted at 12-18 months postvaccination; modest 2-fold increases were observed with a second RSVPreF3 vaccination. CONCLUSIONS: This study indicates RSVPreF3 coadministration with dTpa induces robust immune responses and is well tolerated, regardless of the RSVPreF3 dose level used. CLINICAL TRIALS REGISTRATION: NCT04138056.

YAP1 regulates esophageal stem cells' self-renewal and differentiation.

Esophageal epithelium is one of the most proliferative and regenerative epithelia in our body, indicating robust stem cell activity. However, the underlying mechanisms regulating the self-renewal and differentiation of esophageal stem cells need to be more elucidated. Here, we identify the role of YAP1 in esophageal stem cells. YAP1 is differentially expressed in the nuclei of esophageal basal cells. Furthermore, the treatment of verteporfin, a YAP1 inhibitor, interfered with esophageal organoid formation. Consistently, YAP1 deletion decreased esophageal organoid formation and the expression of basal genes while increasing the expression of suprabasal genes. Finally, global transcriptomic analysis revealed that YAP1 inhibition induced a significant enrichment of gene sets related to keratinization and cornification, while depleting gene sets related to DNA repair and chromosome maintenance. Our data uncover a novel regulatory mechanism for esophageal stem cells, which could provide a potential strategy for esophageal regenerative medicine.

Population Attributable Risk of Wheeze in 2-<6-Year-old Children, Following a Respiratory Syncytial Virus Lower Respiratory Tract Infection in The First 2 Years of Life.

BACKGROUND: There is limited evidence regarding the proportion of wheeze in young children attributable to respiratory syncytial virus lower respiratory tract infections (RSV-LRTI) occurring early in life. This cohort study prospectively determined the population attributable risk (PAR) and risk percent (PAR%) of wheeze in 2-<6-year-old children previously surveilled in a primary study for RSV-LRTI from birth to their second birthday (RSV-LRTI<2Y). METHODS: From 2013 to 2021, 2-year-old children from 8 countries were enrolled in this extension study (NCT01995175) and were followed through quarterly surveillance contacts until their sixth birthday for the occurrence of parent-reported wheeze, medically-attended wheeze or recurrent wheeze episodes (≥4 episodes/year). PAR% was calculated as PAR divided by the cumulative incidence of wheeze in all participants. RESULTS: Of 1395 children included in the analyses, 126 had documented RSV-LRTI<2Y. Cumulative incidences were higher for reported (38.1% vs. 13.6%), medically-attended (30.2% vs. 11.8%) and recurrent wheeze outcomes (4.0% vs. 0.6%) in participants with RSV-LRTI<2Y than those without RSV-LRTI<2Y. The PARs for all episodes of reported, medically-attended and recurrent wheeze were 22.2, 16.6 and 3.1 per 1000 children, corresponding to PAR% of 14.1%, 12.3% and 35.9%. In univariate analyses, all 3 wheeze outcomes were strongly associated with RSV-LRTI<2Y (all global P < 0.01). Multivariable modeling for medically-attended wheeze showed a strong association with RSV-LRTI after adjustment for covariates (global P < 0.0001). CONCLUSIONS: A substantial amount of wheeze from the second to sixth birthday is potentially attributable to RSV-LRTI<2Y. Prevention of RSV-LRTI<2Y could potentially reduce wheezing episodes in 2-<6-year-old children.