Safety and immunogenicity of a new trivalent inactivated split-virus influenza vaccine in healthy Korean children: a randomized, double-blinded, active-controlled, phase III study

Immunogenicity and safety of the first indigenously developed Indian tetravalent influenza vaccine (split virion) in healthy children (6 months to 17 years of age): a randomized, multicenter, phase III clinical trial

This phase III clinical trial was conducted to evaluate the immunogenicity and safety of the Tetravalent Influenza Vaccine (Split virion) I.P. (TetIV), containing two strains each of influenza A and B, developed indigenously in the country for the first time by M/s Cadila Healthcare Limited, India for use in the pediatric population (6 months -17 years of age), and compare it to that of a licensed seasonal Trivalent Influenza Vaccine (TriIV) of Sanofi Pasteur India Private Limited, containing two influenza A and one influenza B strains. Three hundred six subjects of either sex, 6 months to 17 years of age, were randomized in a 1:1 ratio to receive either TetIV or TriIV. Immunogenicity assessments (antibodies against A/H1N1, A/H3N2, B/Phuket, and B/Brisbane) were performed using the hemagglutination inhibition assay at baseline and 28 days after the last vaccination. TetIV was found to fulfill the criteria set by the United States Food and Drug Administration on the requirements of clinical data for licensure of seasonal inactivated influenza vaccines for the pediatric population. The seroconversion rates with TetIV were 94.6% for A/H1N1, 93.9% for A/H3N2, 91.2% for B/Brisbane, and 87.2% for B/Phuket strains. TetIV showed non-inferiority and superiority in immune response, as compared to TriIV, against the shared strains and an additional B strain, respectively. Both the vaccines were tolerated well by all the study participants, and an addition of the fourth strain in TetIV did not compromise the safety as compared to that of TriIV. The most common adverse event reported in both groups was fever.

A Randomized, Double-blind, Active-controlled Clinical Trial of a Cell Culture-derived Inactivated Trivalent Influenza Vaccine (NBP607) in Healthy Children 6 Months Through 18 Years of Age

BACKGROUND

Although a number of cell culture-derived influenza vaccines have been approved for use in adults, there have been few clinical trials of cell culture-derived seasonal influenza vaccines for young children.

METHODS

We conducted a randomized, double-blind phase III clinical trial to evaluate the safety and immunogenicity of a cell culture-derived subunit trivalent inactivated influenza vaccine (NBP607, SK Chemicals Co., Ltd., Seongnam, Korea) in healthy children 6 months of age through 18 years. Subjects were randomized to receive either a study vaccine or an egg-based control vaccine. Antibody levels were measured by the hemagglutination inhibition assay, using cell-derived antigens. Solicited adverse events were assessed for 7 days after each injection. Serious adverse events were collected for 6 months after vaccination.

RESULTS

A total of 374 participants completed the study. No deaths, vaccine-related serious adverse events or withdrawals resulting from adverse events were reported. Rates of solicited and unsolicited adverse events were similar in 2 groups. Overall, NBP607 met the immunogenicity criteria of the Committee for Proprietary Medicinal Products for the 3 influenza strains. Between the NBP607 group and the control group, immunogenicity endpoints were comparable. Participants younger than 3 years of age had lower immunologic responses against the influenza B virus in both the NBP607 group and the control group.

CONCLUSIONS

The immunogenicity and safety were comparable between the NBP607 group and the control group. NBP607 is well tolerated and immunogenic in children 6 months of age through 18 years.

Safety and Immunogenicity of an Egg-Cultivated Quadrivalent Inactivated Split-virion Influenza Vaccine (GC3110A) in Healthy Korean Children: a Randomized, Double-blinded, Active-controlled Phase III Study

BACKGROUND

The frequency with which the 2 B lineages have been found to cocirculate in a season has been on the rise, which has spurred the need for a quadrivalent influenza vaccine (QIV) to protect against both B lineages. The World Health Organization (WHO) recommended that QIV include both B lineages beginning in the 2013-2014 flu season. This study was conducted to evaluate the immunogenicity and safety of an egg-cultivated QIV in healthy Korean children and adolescents aged ≥ 6 months to < 19 years.

METHODS

A total of 528 subjects were randomized 4:1 to receive either a QIV (GC3110A) or a trivalent influenza vaccine. Hemagglutination inhibition antibody responses were assessed 28 days after the last dose. Safety was also evaluated.

RESULTS

The proportion of subjects in the GC3110A group who achieved seroconversion was confirmed to exceed 40% across all age groups. The proportion of subjects aged ≥ 6 months to < 3 years in the GC3110A group who achieved seroprotection failed to meet the Ministry of Food and Drug Safety (MFDS) standard of 70%. Potential causes may include the small number of subjects, as well as the small dosage. However, results pertaining to the other age groups satisfied the MFDS standard. The safety profile was also comparable to that of the control.

CONCLUSION

The new quadrivalent split influenza vaccine may offer broader protection to children and adolescents aged ≥ 3 years to < 19 years of age against both influenza B lineages than the existing trivalent influenza vaccines (Registered at the ClinicalTrials.gov NCT02541253).

Immunogenicity and safety assessment of a trivalent, inactivated split influenza vaccine in Korean children: Double-blind, randomized, active-controlled multicenter phase III clinical trial

A multicenter, double-blind, randomized, active-control phase III clinical trial was performed to assess the immunogenicity and safety of a trivalent, inactivated split influenza vaccine. Korean children between the ages of 6 months and 18 y were enrolled and randomized into a study (study vaccine) or a control vaccine group (commercially available trivalent, inactivated split influenza vaccine) in a 5:1 ratio. Antibody responses were determined using hemagglutination inhibition assay, and post-vaccination immunogenicity was assessed based on seroconversion and seroprotection rates. For safety assessment, solicited local and systemic adverse events up to 28 d after vaccination and unsolicited adverse events up to 6 months after vaccination were evaluated. Immunogenicity was assessed in 337 and 68 children of the study and control groups. In the study vaccine group, seroconversion rates against influenza A/H1N1, A/H3N2, and B strains were 62.0% (95% CI: 56.8–67.2), 53.4% (95% CI: 48.1–58.7), and 54.9% (95% CI: 48.1–60.2), respectively. The corresponding seroprotection rates were 95.0% (95% CI: 92.6–97.3), 93.8% (95% CI: 91.2–96.4), and 95.3% (95% CI: 93.0–97.5). The lower 95% CI limits of the seroconversion and seroprotection rates were over 40% and 70%, respectively, against all strains. Seroconversion and seroprotection rates were not significantly different between the study and control vaccine groups. Furthermore, the frequencies of adverse events were not significantly different between the 2 vaccine groups, and no serious vaccination-related adverse events were noted. In conclusion, the study vaccine exhibited substantial immunogenicity and safety in Korean children and is expected to be clinically effective.

Systematic review of fever, febrile convulsions and serious adverse events following administration of inactivated trivalent influenza vaccines in children

In 2010, increased febrile convulsions (FC) occurred after administration of inactivated trivalent influenza vaccine (TIV) in Australia. We systematically reviewed the rates of fever, FC and serious adverse events (SAEs) after TIV, focussing on published and unpublished clinical trial data from 2005 to 2012, and performed meta-analysis of fever rates. From 4,372 records in electronic databases, 18 randomised controlled trials (RCTs), 14 non-randomised clinical trials, six observational studies and 12 registered trials (five RCTs and seven non-randomised) were identified. In published RCTs, fever ≥ 38 °C rates after first dose of non-adjuvanted TIV were 6.7% and 6.9% for children aged 6–35 months and ≥ 3 years, respectively. Analysis of RCTs by vaccine manufacturer showed pooled fever estimates up to 5.1% with Sanofi or GlaxoSmithKline vaccines; bioCSL vaccines were used in two non-randomised clinical trials and one unpublished RCT and were associated with fever in 22.5–37.1% for children aged 6–35 months. In RCTs, FCs occurred at a rate of 1.1 per 1,000 vaccinated children. While most TIVs induced acceptably low fever rates, bioCSL influenza vaccines were associated with much higher rates of fever in young children. Future standardised study methodology and access to individual level data would be illuminating.

Mucosal adjuvants for influenza virus-like particle vaccine

To find an effective mucosal adjuvant for influenza virus-like particles (VLPs), we compared the effects of known adjuvants Alum, CpG DNA, monophosphoryl lipid A (MPL), poly IC, gardiquimod, and cholera toxin (CT). Mice that were intranasally immunized with Alum, CpG, MPL, and CT adjuvanted VLPs showed higher levels of antibodies in both sera and mucosa. Hemagglutination inhibition and virus neutralizing activities were enhanced in groups adjuvanted with Alum, MPL, or CT. Influenza virus specific long-lived cells secreting IgG and IgA antibodies were found at high levels both in bone marrow and spleen in the Alum, CpG and CT adjuvanted groups. A similar level of protection was observed among different adjuvanted groups, except the CT adjuvant that showed a higher efficacy in lowering lung viral loads after challenge. Alum and CT adjuvants differentially increased influenza VLP-mediated activation of dendritic cells and splenocytes in vitro, supporting the in vivo pattern of antibody isotypes and cytokine production. These results suggest that Alum, MPL, or CpG adjuvants, which have been tested clinically, can be developed as an effective mucosal adjuvant for influenza VLP vaccines.

Neurologic complications and outcomes of pandemic (H1N1) 2009 in Korean children

Neurologic complications of children with influenza A H1N1 2009 pandemic, diagnosed in two consecutive influenza seasons were retrospectively reviewed to seek better outcomes in future outbreaks. Patient demographics, clinical manifestations and neurologic outcomes were reviewed. A total of 1,389 children were diagnosed with influenza A H1N1 by real-time reverse transcriptase-polymerase chain reaction. Of these, 23 (1.7%) patients had neurologic involvement. Their mean age was 5.9 ± 3.6 yr (range, 6 months to 11 yr) and 16 (69.9%) were boys. None of the 23 patients had been vaccinated for influenza A H1N1 and seasonal influenzas. Twenty-two of the 23 patients presented with seizures. Clinical features included febrile convulsion (n = 19), afebrile convulsion (n = 1), aseptic meningitis (n = 1), encephalopathy (n = 1), and acute necrotizing encephalopathy (n = 1). They all were treated with Oseltamivir twice daily for 5 days immediately after nasal and throat swab testing. Twenty-one of the subjects recovered fully, but the youngest two infants experienced severe neurological sequelae. The results indicate that neurologic complications associated with influenza A H1N1 2009 pandemic were mostly mild, but rarely were serious. Prompt intervention leads to a better outcome and vaccination may prevent the disease, thus staving off serious neurological complications following influenza, especially in young infants.