High-Dose Quadrivalent Influenza Vaccine for Prevention of Cardiovascular and Respiratory Hospitalizations in Older Adults.

Background: We assessed the relative vaccine effectiveness (rVE) of high-dose quadrivalent influenza vaccine (QIV-HD) versus standard-dose quadrivalent influenza vaccine (QIV-SD) in preventing respiratory or cardiovascular hospitalizations in older adults.

Methods: FinFluHD was a phase 3b/4 modified double-blind, randomized pragmatic trial. Enrolment of 121,000 adults ≥65 years was planned over three influenza seasons (October to December 2019-2021).

Antibody-mediated NK cell activation as a correlate of immunity against influenza infection.

Antibodies play a critical role in protection against influenza; yet titers and viral neutralization represent incomplete correlates of immunity. Instead, the ability of antibodies to leverage the antiviral power of the innate immune system has been implicated in protection from and clearance of influenza infection. Here, post-hoc analysis of the humoral immune response to influenza is comprehensively profiled in a cohort of vaccinated older adults (65 + ) monitored for influenza infection during the 2012/2013 season in the United States (NCT: 01427309).

Superior immunogenicity of high-dose quadrivalent inactivated influenza vaccine versus Standard-Dose vaccine in Japanese Adults ≥ 60 years of age: Results from a phase III, randomized clinical trial.

Background: A high-dose, split-virion inactivated quadrivalent influenza vaccine (IIV4-HD; Sanofi) is being used for the prevention of influenza in multiple countries. This study examined the immunogenicity and safety of the IIV4-HD vaccine administered intramuscularly (IM) compared with a locally licensed standard-dose influenza vaccine (IIV4-SD) administered subcutaneously (SC) in Japan.

Methods: This was a phase III, randomized, modified double-blind, active-controlled, multi-center study in older adults ≥ 60 years of age conducted during the Northern Hemisphere (NH) influenza season of 2020-21 in Japan.

Immunological non-inferiority and safety of a quadrivalent inactivated influenza vaccine versus two trivalent inactivated influenza vaccines in China: Results from two studies.

Who Universal Trial Numbers (utns): U1111-1174-4615 and U1111-1174-4698.

Clinicaltrials.gov: NCT04210349 and NCT03430089.

Effectiveness of the quadrivalent high-dose influenza vaccine for prevention of cardiovascular and respiratory events in people aged 65 years and above: Rationale and design of a real-world pragmatic randomized clinical trial.

Background: Influenza has been an acknowledged cause of respiratory disease for decades. However, considerable related, and often unappreciated, disease burden stems from cardiovascular complications, exacerbations of underlying medical conditions and secondary respiratory complications, with the highest burden in the elderly. This novel study combines the gold standard method of a randomized controlled trial with real-world data collection through national registries, to assess the relative effectiveness of high-dose (QIV-HD) vs standard-dose quadrivalent influenza vaccine (QIV-SD) in preventing cardio-respiratory hospitalizations in a large cohort of adults aged ≥65 years.

Safety and immunogenicity of high doses of quadrivalent influenza vaccine in children 6 months through <18 years of age: A randomized controlled phase II dose-finding trial.

Quadrivalent high-dose inactivated influenza vaccine (Fluzone® High-Dose Quadrivalent, IIV4-HD) was licensed in the USA in 2019 for adults ≥ 65 years of age. This Phase II study examined safety and immunogenicity of 3 dose formulations of IIV4-HD in healthy children. In a randomized, modified double-blind, active-controlled trial in the USA and Canada, 661 children aged 6 months through < 18 years received 1 or 2 doses intramuscularly of standard-dose quadrivalent influenza vaccine (IIV4-SD; 15 µg HA/strain), IIV4-HD at 3 dose levels (30, 45, and 60 µg HA/strain), or adjuvanted trivalent influenza vaccine (aIIV3, 7.

Immunogenicity and safety of a multi-dose quadrivalent inactivated influenza vaccine in individuals aged 6 months to 17 years: a randomized phase III trial.

Annual vaccination is the most effective way to prevent seasonal influenza. Influenza vaccines in multi-dose vial (MDV) formats can facilitate timely vaccination of large populations by reducing per-dose costs and cold storage requirements compared to single-dose pre-filled syringe (PFS) formats. MDV vaccines require thiomersal or another preservative to prevent microbial contamination.

Impact of a quadrivalent inactivated influenza vaccine on influenza-associated complications and health care use in children aged 6 to 35 months: Analysis of data from a phase III trial in the Northern and Southern Hemispheres.

Background: A multi-season phase III trial conducted in the Northern and Southern Hemispheres demonstrated the efficacy of a quadrivalent split-virion inactivated influenza vaccine (IIV4) in children 6-35 months of age.

Methods: Data collected during the phase III trial were analysed to examine the vaccine efficacy (VE) of IIV4 in preventing laboratory-confirmed influenza in age subgroups and to determine the relative risk for IIV4 vs. placebo for severe outcomes, healthcare use, and parental absenteeism from work associated with laboratory-confirmed influenza.

Efficacy, immunogenicity, and safety of a quadrivalent inactivated influenza vaccine in children aged 6-35 months: A multi-season randomised placebo-controlled trial in the Northern and Southern Hemispheres.

Background: A quadrivalent split-virion inactivated influenza vaccine (VaxigripTetra™, Sanofi Pasteur; IIV4) containing two A strains (H1N1 and H3N2) and B strains from both lineages (Victoria and Yamagata) was approved in Europe in 2016 for individuals aged ≥ 3 years. This study examined the efficacy and safety of IIV4 in children aged 6-35 months.

Methods: This was a phase III randomised controlled trial conducted in Latin America, Asia, Africa, and Europe during the Northern Hemisphere 2014/2015 and 2015/2016 and Southern Hemisphere 2014 and 2015 influenza seasons.

Quadrivalent inactivated influenza vaccine (VaxigripTetra™).

VaxigripTetra™ (IIV4; Sanofi Pasteur) is a quadrivalent split-virion influenza vaccine approved in Europe in 2016 for individuals ≥ 3 years of age. IIV4 builds on the well-established record of the trivalent split-virion influenza vaccine (Vaxigrip®). Areas covered: This literature review summarizes the rationale for developing quadrivalent influenza vaccines and discusses the phase III clinical trial results supporting the immunogenicity, safety, and tolerability of IIV4.

Safety and immunogenicity of two subunit influenza vaccines in healthy children, adults and the elderly: a randomized controlled trial in China.

The burden of influenza is well known in the elderly and at-risk patients, but also in children. Especially in those under 5 years old, influenza may cause severe morbidity and mortality. Influenza infections and complications can be reduced by vaccination.

Antibody induction by virosomal, MF59-adjuvanted, or conventional influenza vaccines in the elderly.

In a randomized, observer-blind, three-arm, parallel group, multi-centre trial including 386 elderly subjects in four countries, the immunogenicity and safety was studied of three different trivalent inactivated surface antigen (subunit) influenza vaccine types: a conventional subunit influenza vaccine (SIV, brand: Influvac and two newer vaccines: a MF59-adjuvanted subunit influenza vaccine (adSIV, brand: Fluad and a virosomal subunit influenza vaccine (vSIV, brand: Invivac. All vaccines were trivalent containing 15 microg hemagglutinin of each virus strain as recommended by the World Health Organization for the 2004-2005 season. The study was designed to demonstrate the serological non-inferiority of vSIV to both adSIV and SIV in elderly persons.

On the bias in HI titers and how to reduce it.

HI titers measure anti-HA antibody concentrations in sera. By the way they are defined standard titers underestimate the true amounts of antibody. A new definition is proposed, the mid-value definition.

The European CHMP criteria for influenza vaccine immunogenicity cannot be improved by the use of confidence intervals.

In a well-know CHMP Note for Guidance criteria are given for evaluation the results of annual-update studies. Now and then it sometimes is suggested that these criteria can be improved by the use of confidence intervals. Here it is argued that this is based on a misinterpretation of what confidence intervals are.