Vaxelis (diphtheria and tetanus toxoids and acellular pertussis vaccine adsorbed, inactivated poliovirus, haemophilus b conjugate and hepatitis B vaccine) / Merck (MSD), Sanofi - LARVOL DELTA

PRE-BOOSTER IMMUNE RESPONSE TO HEXAVALENT VACCINES IN UK INFANTS AGED 18 MONTHS (ESPID 2026) - "Method UK-based infants receiving a three-dose Infanrix hexa (Hex-I) or Vaxelis (Hex-V) hexavalent vaccine schedule at 2-3-4 months were recruited at 12-months of age with no Hib/MenC given. Significantly higher antibody titres were observed against pertussis filamentous hemagglutinin and polio type I in Hex-I-primed compared to Hex-V-primed infants. Conclusions/Learning Points These data show persistence of anti-PRP antibodies at 14-months post-prime vaccinations for both hexavalent vaccines; however, a higher proportion of Hex-I-primed infants had anti-PRP levels below the protective threshold."

Infectious Disease • Influenza

A RANDOMISED CONTROL TRIAL EVALUATING IMMUNOGENICITY FOLLOWING INTERCHANGEABLE USE OF TWO HEXAVALENT VACCINES FOR BOOSTER IMMUNISATION: THE 6-IN-1 PART 2 STUDY (ESPID 2026) - "We investigated the interchangeability of Infanrix hexa (HexI) or Vaxelis (HexV) as hexavalent vaccines used in primary and booster immunisation. Conclusions/Learning Points High proportions of infants with anti-PRP concentrations at/above the 1.0µg/mL protection threshold were observed across all groups. Seroprotection against Hib at 1-month post-booster in heterologous hexavalent booster schedules were non-inferior to homologous schedules, supporting interchangeability of HexI and HexV boosters."

Clinical • Infectious Disease

PARENTAL MOTIVATIONS AND EXPERIENCES IN THE 6-IN-1 PART 2 VACCINE TRIAL STUDY (ESPID 2026) - "Background The 6-in-1 part 2 study evaluated the interchangeability of Infanrix Hexa and Vaxelis, and giving the second MMR dose at 18 months in the context of the UK infant immunisation schedule. Conclusions/Learning Points Offering a variety of recruitment methods is likely to be important and should be maintained to facilitate participation. Understanding parent motivations - child safety, altruism, and direct benefit - can help optimise the design of trials and trial materials to increase recruitment and trial completion."

Infectious Disease • Novel Coronavirus Disease • Varicella Zoster

Study of the Safety of a 21-valent Pneumococcal Conjugate Vaccine in Healthy Infants From Approximately 2 Months of Age (clinicaltrials.gov) - P3 | N=2360 | Active, not recruiting | Sponsor: Sanofi | Recruiting ➔ Active, not recruiting | Trial completion date: May 2027 ➔ Oct 2027 | Trial primary completion date: May 2027 ➔ Oct 2027

Enrollment closed • Trial completion date • Trial primary completion date • Infectious Disease • Pneumococcal Infections

Surveillance of adverse events following immunisation in Australia, 2023. (PubMed, Commun Dis Intell (2018)) - "The most commonly reported adverse events for new vaccines introduced in 2023 were medication errors and headache for COVID-19 vaccines; hypersensitivity and pyrexia for DTPa-HepB-IPV-Hib vaccine (Vaxelis); and injection site reaction and hypersensitivity for recombinant zoster vaccine (Shingrix). There was reduction in deaths reported following vaccination in 2023 compared to 2022 and 2021. None of the 34 reported deaths in 2023 were determined to be causally related to the vaccine(s) received."

Adverse events • Journal • Herpes Zoster • Immunology • Infectious Disease • Novel Coronavirus Disease • Pain • Respiratory Diseases

Study of a 4-Dose Regimen of a 21-valent Pneumococcal Conjugate Vaccine in Healthy Infants From Approximately 2 Months of Age (clinicaltrials.gov) - P3 | N=1714 | Active, not recruiting | Sponsor: Sanofi Pasteur, a Sanofi Company | Recruiting ➔ Active, not recruiting

Enrollment closed • Infectious Disease • Pneumococcal Infections

Study of Mixed Vaccination Schedules With a 21-valent Pneumococcal Conjugate Vaccine and a 20-valent Pneumococcal Conjugate Vaccine in Healthy Infants From Approximately 2 Months of Age (clinicaltrials.gov) - P3 | N=580 | Active, not recruiting | Sponsor: Sanofi | Recruiting ➔ Active, not recruiting

Enrollment closed • Infectious Disease • Pneumococcal Infections

Safety and Immunogenicity of an Investigational Pentavalent Meningococcal ABCYW Vaccine Against Meningococcal Disease in Children, Toddlers, and Infants (clinicaltrials.gov) - P1/2 | N=750 | Active, not recruiting | Sponsor: Sanofi Pasteur, a Sanofi Company | Recruiting ➔ Active, not recruiting

Enrollment closed • Infectious Disease • Meningococcal Infections • Pediatrics

CORAL: Co-administration Study of an Investigational Live-Attenuated Respiratory Syncytial Virus Vaccine in Infants and Toddlers (clinicaltrials.gov) - P3 | N=2226 | Terminated | Sponsor: Sanofi Pasteur, a Sanofi Company | Active, not recruiting ➔ Terminated; Sponsor decision

Trial termination • Pediatrics • Respiratory Diseases • Respiratory Syncytial Virus Infections

Lot-to-lot Consistency Study of a 21-valent Pneumococcal Conjugate Vaccine in Healthy Infants From 2 Months of Age (clinicaltrials.gov) - P3 | N=896 | Recruiting | Sponsor: Sanofi | Not yet recruiting ➔ Recruiting

Enrollment open • Infectious Disease • Pneumococcal Infections

Lot-to-lot Consistency Study of a 21-valent Pneumococcal Conjugate Vaccine in Healthy Infants From 2 Months of Age (clinicaltrials.gov) - P3 | N=896 | Not yet recruiting | Sponsor: Sanofi

New P3 trial • Infectious Disease • Pneumococcal Infections

MADI-02: Maternal Determinants of Infant Immunity to Pertussis (clinicaltrials.gov) - P4 | N=200 | Completed | Sponsor: Centre Hospitalier Universitaire Saint Pierre | Recruiting ➔ Completed | Trial primary completion date: Aug 2025 ➔ Dec 2025

Trial completion • Trial primary completion date • Infectious Disease • Pertussis • Respiratory Diseases

Cmss1 limits FMDV infection by enhancing antigen presentation and CD8+ T cell responses. (PubMed, J Virol) - "We identified VP419-30 as an immunodominant CD8+ T cell epitope of FMDV and established an in vitro system to evaluate the antigen-presenting capacities. Based on these findings, we validate Cmss1 as a novel host factor in antigen processing and presentation during FMDV infection. Since DCs play critical roles in mediating immune responses, our findings comprehensively characterize the immune features of dendritic cells for the first time and present a new mechanism through which the host defends against FMDV infection, suggesting Cmss1 as a novel potential target for antiviral therapies."

Journal • Infectious Disease • CD8 • IFNAR2

Infant protection from invasive Haemophilus influenzae type b disease using the PRP-OMPC conjugate vaccine: An update. (PubMed, Hum Vaccin Immunother) - "Additional studies that are recently published address previously open questions regarding Vaxelis, including immunogenicity after the first infant dose, co-administration with meningococcal B vaccine, and interchangeability with other hexavalent vaccines. This brief review summarizes recently published Vaxelis data, with potential implications for ongoing control of invasive Hib disease in Europe."

Journal • Review • Infectious Disease • Influenza • Meningococcal Infections • Pediatrics • Respiratory Diseases • Tetanus

Study of Mixed Vaccination Schedules With a 21-valent Pneumococcal Conjugate Vaccine and a 20-valent Pneumococcal Conjugate Vaccine in Healthy Infants From Approximately 2 Months of Age (clinicaltrials.gov) - P3 | N=580 | Recruiting | Sponsor: Sanofi | Trial completion date: May 2027 ➔ Aug 2027 | Trial primary completion date: May 2027 ➔ Aug 2027

Trial completion date • Trial primary completion date • Infectious Disease • Pneumococcal Infections

PRELIMINARY ANALYSIS OF PRE-BOOSTER IMMUNE RESPONSE TO HEXAVALENT VACCINES FOLLOWING THREE-DOSE PRIME VACCINATION IN PRETERM INFANTS (ESPID 2025) - "Methods UK-based infants receiving a three-dose Infanrix hexa (Hex-I) or Vaxelis (Hex-V) hexavalent vaccine schedule at 2-3-4 months were recruited at 12-months and not given Hib/MenC. Sample analysis is ongoing; more samples expected by May 2025. Conclusions/Learning Points These preliminary data suggest that infants born preterm have lower anti-PRP antibodies at 18-months than term infants and could be at increased risk of Hib infection prior to booster vaccination."

Prematurity • Hepatitis B • Infectious Disease • Influenza • Pertussis

Study of Mixed Vaccination Schedules With a 21-valent Pneumococcal Conjugate Vaccine and a 20-valent Pneumococcal Conjugate Vaccine in Healthy Infants From Approximately 2 Months of Age (clinicaltrials.gov) - P3 | N=580 | Recruiting | Sponsor: Sanofi | Not yet recruiting ➔ Recruiting

Enrollment open • Infectious Disease • Pneumococcal Infections

Study of the Safety of a 21-valent Pneumococcal Conjugate Vaccine in Healthy Infants From Approximately 2 Months of Age (clinicaltrials.gov) - P3 | N=2320 | Recruiting | Sponsor: Sanofi | Not yet recruiting ➔ Recruiting

Enrollment open • Infectious Disease • Pneumococcal Infections

MADI-02: Maternal Determinants of Infant Immunity to Pertussis (clinicaltrials.gov) - P4 | N=200 | Recruiting | Sponsor: Centre Hospitalier Universitaire Saint Pierre | Trial primary completion date: Dec 2024 ➔ Aug 2025

Trial primary completion date • Infectious Disease • Pertussis • Respiratory Diseases

Study of the Safety of a 21-valent Pneumococcal Conjugate Vaccine in Healthy Infants From Approximately 2 Months of Age (clinicaltrials.gov) - P3 | N=2320 | Not yet recruiting | Sponsor: Sanofi

New P3 trial • Infectious Disease • Pneumococcal Infections

Study of Mixed Vaccination Schedules With a 21-valent Pneumococcal Conjugate Vaccine and a 20-valent Pneumococcal Conjugate Vaccine in Healthy Infants From Approximately 2 Months of Age (clinicaltrials.gov) - P3 | N=580 | Not yet recruiting | Sponsor: Sanofi

New P3 trial • Infectious Disease • Pneumococcal Infections

Preferences of nurses in the United Kingdom for attributes of pediatric hexavalent vaccines: a discrete-choice experiment. (PubMed, Expert Rev Pharmacoecon Outcomes Res) - "Nurses generally preferred vaccines that have been available for longer than 3 years versus less than 1 year. Nurses did not have clear preferences either way on plastic blister in packaging or for how long vaccines can be stored at room temperature before needing to be discarded.In this survey, nurses' preferences were mainly influenced by device type, preferring ready-to-use vaccines available as pre-filled syringes to vaccines that need to be mixed before use."

Journal • Cough • Hepatitis B • Hepatology • Infectious Disease • Inflammation • Influenza • Pediatrics • Pertussis • Respiratory Diseases • Tetanus

CORAL: Co-administration Study of an Investigational Live-Attenuated Respiratory Syncytial Virus Vaccine in Infants and Toddlers (clinicaltrials.gov) - P3 | N=2226 | Active, not recruiting | Sponsor: Sanofi Pasteur, a Sanofi Company | Recruiting ➔ Active, not recruiting

Enrollment closed • Pediatrics • Respiratory Diseases • Respiratory Syncytial Virus Infections

Study of a 4-Dose Regimen of a 21-valent Pneumococcal Conjugate Vaccine in Healthy Infants From Approximately 2 Months of Age (clinicaltrials.gov) - P3 | N=1630 | Recruiting | Sponsor: Sanofi Pasteur, a Sanofi Company | Not yet recruiting ➔ Recruiting

Enrollment open • Infectious Disease • Pneumococcal Infections

Study of a 4-Dose Regimen of a 21-valent Pneumococcal Conjugate Vaccine in Healthy Infants From Approximately 2 Months of Age (clinicaltrials.gov) - P3 | N=1630 | Not yet recruiting | Sponsor: Sanofi Pasteur, a Sanofi Company

New P3 trial • Infectious Disease • Pneumococcal Infections