Corwin A. Robertson

Safety and immunogenicity of a quadrivalent inactivated influenza vaccine compared to licensed trivalent inactivated influenza vaccines in adults

PURPOSE To evaluate the safety and immunogenicity of a prototype quadrivalent inactivated influenza vaccine (QIV) containing two influenza B strains, one of each lineage, compared with licensed trivalent inactivated influenza vaccines (TIVs) containing either a Victoria B-lineage strain (2009-2010 TIV) or a Yamagata B-lineage strain (2008-2009 TIV). METHODS Healthy adults ≥18 years of age were eligible to participate in this phase II, open-label, randomized, controlled, multicenter study conducted in the US. Participants received a single dose of 2009-2010 TIV, 2008-2009 TIV, or QIV. Sera were collected before and 21 days after vaccine administration to test for hemagglutination inhibition (HAI) antibodies to each of the four influenza strains. Immunogenicity endpoints included geometric mean HAI antibody titers (GMTs) and rates of seroprotection (titer ≥1:40) and seroconversion (4-fold rise pre- to post-vaccination). Safety endpoints included frequency of solicited injection-site and systemic reactions occurring within 3 days of vaccination, and unsolicited non-serious adverse events (AEs) and serious AEs (SAEs) within 21 days of vaccination. RESULTS One hundred and ninety participants were enrolled to each vaccine group. QIV induced GMTs to each A and B strain that were noninferior to those induced by the 2009-2010 and 2008-2009 TIVs (i.e., lower limit of the two-sided 95% confidence interval of the ratio of GMT(QIV)/GMT(TIV)>0.66 for each strain). Rates of seroprotection and seroconversion were similar in all groups. Incidence and severity of solicited injection-site and systemic reactions, AEs, and SAEs were similar among groups. CONCLUSION QIV, containing two B strains (one from each B lineage), was as safe and immunogenic as licensed TIV. QIV has the potential to be a useful alternative to TIV and offer protection against both B lineages.

Prevention of serious events in adults 65 years of age or older: A comparison between high-dose and standard-dose inactivated influenza vaccines

BACKGROUND A recent study showed that a high-dose inactivated influenza vaccine (IIV-HD) was 24.2% more efficacious than a standard-dose inactivated influenza vaccine (IIV-SD) in preventing laboratory-confirmed symptomatic influenza in adults ≥65 years. Here we evaluate the effectiveness of IIV-HD compared to IIV-SD in preventing serious illnesses considered potential sequelae or complications of influenza infection. METHODS The original study was a double-blind, randomized, active-controlled, multicenter trial. Participants were adults ≥65 years randomized to receive IIV-HD or IIV-SD, and followed for 6-8 months post-vaccination for the occurrence of influenza and serious adverse events (SAEs). SAEs were events: leading to death or hospitalization (or its prolongation); considered life-threatening or medically important; or resulting in disability. For the present analysis, reported SAEs were classified as possibly related to influenza by three blinded physicians and rates per 1000 participant-seasons were calculated. Relative vaccine effectiveness (rVE) was estimated as (1-Rate Ratio)×100. RESULTS 31,989 participants were enrolled, with 15,991 and 15,998 randomized to receive IIV-HD and IIV-SD, respectively. IIV-HD was significantly more effective than IIV-SD in preventing SAEs possibly related to influenza overall (rVE, 17.7%; 95% confidence interval [CI], 6.6-27.4%) and serious pneumonia (rVE, 39.8%; 95% CI, 19.3-55.1%). Borderline significance was observed for the efficacy of IIV-HD relative to IIV-SD for the prevention of all-cause hospitalizations (rVE, 6.9%; 95% CI, 0.5-12.8%). CONCLUSIONS Compared to IIV-SD, IIV-HD reduced the risk of SAEs possibly related to influenza. The observed relative effectiveness against serious pneumonia is particularly noteworthy considering the burden of influenza and pneumonia in older adults.

Efficacy and immunogenicity of high-dose influenza vaccine in older adults by age, comorbidities, and frailty.

BACKGROUND A randomized trial demonstrated that a high-dose inactivated influenza vaccine (IIV-HD) was 24.2% more efficacious than a standard-dose vaccine (IIV-SD) against laboratory-confirmed influenza illness in adults ≥65 years. To evaluate the consistency of IIV-HD benefits, supplemental analyses explored efficacy and immunogenicity by baseline characteristics of special interest. METHODS Double-blind, randomized, active-controlled, multicenter trial. Adults ≥65 years were randomized 1:1 to receive IIV-HD or IIV-SD and followed for 6-8 months postvaccination for the occurrence of influenza. One third of participants were randomly selected to provide sera for measurement of hemagglutination inhibition antibody (HAI) titers. Efficacy (IIV-HD vs. IIV-SD) against laboratory-confirmed, protocol-defined influenza-like illness (PD-ILI) and HAI geometric mean titer (GMT) ratios (IIV-HD/IIV-SD) were evaluated by age, and number of high-risk comorbid and frailty conditions. RESULTS Efficacy (95% confidence intervals) of IIV-HD relative to IIV-SD against laboratory-confirmed PD-ILI was 19.7% (0.4%; 35.4%) for participants 65-74 years, 32.4% (8.1%; 50.6%) for those ≥75 years, 22.1% (3.9%; 37.0%) for participants with ≥1 high-risk comorbidity, 23.6% (-3.2%; 43.6%) for those with ≥2 high-risk comorbidities, 27.5% (0.4%; 47.4%) for persons with 1 frailty condition, 23.9% (-9.0%; 47.2%) for those with 2 frailty conditions, and 16.0% (-16.3%; 39.4%) for those with ≥3 frailty conditions. There was no evidence of vaccine efficacy heterogeneity within age, comorbidity, and frailty strata (P-values 0.351, 0.875, and 0.838, respectively). HAI GMT ratios were significantly higher among IIV-HD recipients for all strains and across all subgroups. CONCLUSIONS Estimates of relative efficacy consistently favored IIV-HD over IIV-SD. There was no significant evidence that baseline age, comorbidity, or frailty modified the efficacy of IIV-HD relative to IIV-SD. IIV-HD significantly improved HAI responses for all strains and in all subgroups. IIV-HD is likely to provide benefits beyond IIV-SD for adults ≥65 years, irrespective of age and presence of comorbid or frailty conditions.

Effect of Previous-Year Vaccination on the Efficacy, Immunogenicity, and Safety of High-Dose Inactivated Influenza Vaccine in Older Adults

High-dose inactivated split-virus influenza vaccine showed higher immunogenicity and relative efficacy compared with standard-dose inactivated split-virus influenza vaccine, irrespective of type of vaccine used the preceding year. The safety profile was also unaffected by previous-year vaccine.

Fluzone® High-Dose Influenza Vaccine

ABSTRACT Introduction: Fluzone® High-Dose (IIV3-HD) is a trivalent, inactivated, split-virus influenza vaccine indicated for use in older adults (≥65 years of age). It contains 60 µg hemagglutinin of each influenza strain, which is four times the hemagglutinin content of standard-dose influenza vaccines, including Fluzone (IIV3-SD). IIV3-HD has been licensed for use in older adults in the US since December 2009 and in Canada since February 2016. Areas covered: In this review, we summarize postlicensure studies on the immunogenicity, safety, and effectiveness of IIV3-HD and estimates of its cost-effectiveness in older adults. We also discuss the potential application of IIV3-HD in adults 50–64 years of age and in individuals who may respond poorly to standard-dose influenza vaccines. Expert commentary: Multiple studies conducted since 2004 have consistently shown that, in older adults, IIV3-HD induces substantially greater antibody responses and better protection against influenza and influenza-associated hospitalization than IIV3-SD. Health economic analyses suggest that IIV3-HD can be a cost-effective alternative to standard-dose trivalent or quadrivalent inactivated influenza vaccines and can even be cost-saving compared to IIV3-SD in older adults. Further investigation of IIV3-HD vaccination as a way to improve immune responses and protection against influenza in immunocompromised individuals is warranted.

Post-licensure safety surveillance study of routine use of quadrivalent meningococcal diphtheria toxoid conjugate vaccine

BACKGROUND Menactra® vaccine (MenACWY-D) was licensed in the United States in 2005 for persons 11-55years of age. The aim of this study was to assess the safety of MenACWY-D administered as part of routine clinical care to patients at Kaiser Permanente Northern California (KPNC). METHODS This was an observational, retrospective study that included all KPNC members who received MenACWY-D during the study period. We monitored all vaccine recipients for non-elective hospitalizations, emergency department visits, and selected outcomes captured in the clinic setting (Bells palsy, seizures, neuritis, Guillain-Barré syndrome, encephalopathy, encephalitis, epilepsy, transverse myelitis, multiple sclerosis, hypersensitivity reactions, idiopathic thrombocytopenic purpura, diabetes, arthritis, hemolytic anemia, collagen-vascular disease) through 6months after vaccination. Using vaccine recipients as their own controls, we calculated incidence rate ratios (IRRs) of outcomes during the post-vaccination risk interval and compared these with rates during a comparison interval more remote from vaccination. We also compared rates of outcomes in MenACWY-D recipients with those in matched controls who received selected vaccines in the prior year. We reviewed medical records for selected outcomes. RESULTS From April 2005 through April 2006, 31,561 KPNC patients (>99% of whom were 11-55years of age) received MenACWY-D. Overall, there were 21 outcomes with significantly elevated IRRs and 44 outcomes with significantly reduced IRRs. Medical record review of outcomes with significantly elevated IRRs did not suggest any relationship with MenACWY-D. Two serious adverse events were considered possibly related to vaccination by the study investigator. CONCLUSIONS This study did not detect any safety concerns following MenACWY-D and provides reassurance that MenACWY-D administered as part of routine care was not associated with unexpected safety risks. ClinicalTrials.gov Identifier is NCT00254995.

Vaccine manufacturer’s role in the global vaccine enterprise

Purpose The purpose of this paper is to describe the role of the vaccine manufacturer in the global vaccine enterprise. Design/methodology/approach Narrative review. Findings Pharmaceutical companies involved in the vaccine enterprise play critical and often unrecognized roles in the global health management arena. In addition to the obvious role of vaccine production and distribution, companies are often involved in the identification of infectious agents for which vaccines may be of benefit, basic and applied research, process development, pre-clinical and clinical evaluations of vaccine candidates, as well as continuous post-licensure safety monitoring efforts. Vaccine manufacturers interact with health and regulatory agencies, academia and agencies interested in supporting cost-effective means of vaccine distribution to areas most in need of life-saving vaccines. Originality/value This review provides the reader with an understanding of the many roles of the manufacturer in the global vaccine enterprise.

Safety and immunogenicity of a booster dose of meningococcal (groups A, C, W, and Y) polysaccharide diphtheria toxoid conjugate vaccine.

BACKGROUND Quadrivalent meningococcal conjugate vaccines (MenACWY) were developed to offer long-term protection against invasive disease caused by serogroups A, C, W, and Y. Reduced MenACWY effectiveness within 5 years after primary vaccination (likely due to declining bactericidal antibody titers) has been described, particularly with respect to C and Y disease in the United States. We evaluated the safety and immunogenicity of a single booster dose of quadrivalent meningococcal polysaccharide diphtheria toxoid conjugate vaccine (MenACWY-D) in adolescents and adults who received a previous dose 4-6 years earlier. METHODS This phase 2, open-label, multicenter study of 834 persons was conducted in the United States. Participants received a single 0.5-mL booster dose of MenACWY-D. Serogroup-specific bactericidal antibody geometric mean titers (GMTs) were measured with a serum bactericidal antibody assay using human complement (hSBA). Proportions of participants achieving antibody titers of ⩾1:8 for each vaccine serogroup on Days 6 and 28 were determined. Rates of adverse events (AEs), including serious adverse events (SAEs), were also assessed. RESULTS Before booster vaccination, 38.7-68.5% of participants had an hSBA titer ⩾1:8, depending on vaccine serogroup. By Day 6 post-vaccination, 98.2-99.1% of participants had hSBA titers ⩾1:8. By Day 28, >99% of participants achieved this threshold and the primary hypothesis (lower limit of the one-sided 95% confidence limit ⩾85% for each serogroup) was met. The GMT ratios (post-vaccination divided by pre-vaccination) at Day 28 ranged from 47.2 (serogroup A) to 209.1 (serogroup Y). Rates of AEs, including SAEs, were similar to those observed among adolescents and adults who received a primary dose of MenACWY-D in previous studies. There were no study discontinuations due to an AE and no deaths. CONCLUSIONS Booster vaccination with MenACWY-D was safe and induced robust bactericidal antibody responses, consistent with immune memory, among adolescents and adults 4-6 years after primary vaccination. ClinicalTrials.gov registration: NCT01442675.

Fluzone® Intradermal Quadrivalent Influenza Vaccine

ABSTRACT Introduction: An intradermal version of Fluzone® split-virion inactivated trivalent influenza vaccine, containing 9 µg hemagglutinin per strain of A/H1N1, A/H3N2, and one B lineage virus (Fluzone Intradermal, Sanofi Pasteur), became available in the US during the 2011–2012 influenza season for adults 18–64 years of age. In advance of the 2015–2016 season, Fluzone Intradermal was replaced with Fluzone Intradermal Quadrivalent vaccine, which contains 9 µg hemagglutinin per strain of the two A-strain viruses and both B-strain lineage viruses (Victoria and Yamagata). Areas covered: This literature review summarizes the history and mechanism of intradermal vaccination, discusses the clinical trial results supporting the immunogenicity and safety of Fluzone Intradermal Quadrivalent vaccine, and describes the unique microinjection system used to deliver Fluzone Intradermal Quadrivalent. Expert commentary: Fluzone Intradermal Quadrivalent may boost confidence in influenza vaccination with the addition of a second B-lineage strain. By using an innovative microinjection system, the vaccine is also designed to address some of the logistic challenges faced by healthcare providers administering immunizations.

Prevention and control of influenza and dengue through vaccine development.

Influenza and dengue are viral illnesses of global public health importance, especially among children. Accordingly, these diseases have been the focus of efforts to improve their prevention and control. Influenza vaccination offers the best protection against clinical disease caused by strains contained within the specific years formulation. It is not uncommon for there to be a mismatch between vaccine strains and circulating strains, particularly with regards to the B lineages. For more than a decade, two distinct lineages of influenza B (Yamagata and Victoria) have co-circulated in the US with varying frequencies, but trivalent influenza vaccines contain only one B-lineage strain and do not offer adequate protection against the alternate B-lineage. Quadrivalent influenza vaccines (QIVs), containing two A strains (H1N1 and H3N2) and two B strains (one from each lineage) have been developed to help protect against the four strains predicted to be the most likely to be circulating. The QIV section of this article discusses epidemiology of pediatric influenza, importance of influenza B in children, potential benefits of QIV, and new quadrivalent vaccines. In contrast to influenza, a vaccine against dengue is not yet available in spite of many decades of research and development. A global increase in reports of dengue fever (DF) and its more severe presentations, dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS), suggest that US physicians will increasingly encounter patients with this disease. Similarities of the early signs and symptoms of influenza and dengue and the differences in disease management necessitates a better understanding of the epidemiology, clinical presentation, management, and prevention of DF by US physicians, including pediatricians. The article also provides a brief overview of dengue and discusses dengue vaccine development.