Recombinant IAV H3N2 (A/Ontario/RV1273/2005) Hemagglutinin (a.a. 17-345) [His]

Objective: To assess the immunogenicity and safety of vaccination against seasonal influenza in psoriatic arthritis (PsA) patients treated with secukinumab versus healthy controls (HC). Methods: PsA patients administered secukinumab for >= 3 months and HC received the Sanofi Pasteur vaccine composed of 3 antigens (H3N3, H1N1, and B) and underwent clinical and laboratory assessments on the day of vaccination and 4-6 weeks later. Immunogenicity of the vaccine was evaluated by hemagglutination inhibition assay against those 3 antigens. Responders to each antigen were defined by a 4-fold increase in the antigen titer or by seroconversion in patients whose baseline level was <1/40. Results: Thirty-two consecutive PsA patients treated with secukinumab for >= 3 months comprised the study group, 10 of whom received concomitant conventional synthetic disease-modifying drugs, mostly methotrexate. There were 17 age- and gender-matched HC (median age 48.5 years, 6 females). The geometric mean titers of each antigen increased significantly in both groups. The number of responders in each group was similar for H3N2 and H1N1, and significantly higher for B/Brisbane in the PsA group. The proportion of patients with a seroprotective level (a titer >1/40) was high and similar in both groups. There was no correlation between the response rate and age, gender, or selected parameters of disease activity (tender/swollen joint counts, Leeds enthesitis index, physician and patient global assessment, psoriasis area severity index, and C-reactive protein). No disease exacerbation was observed following the vaccination. No serious adverse effects were observed in both groups during the study period. Conclusion: Secukinumab treatment does not affect the humoral response to influenza vaccine of patients with PsA. (C) 2019 Published by Elsevier Ltd.

Both inactivated influenza vaccines (IIV) and live-attenuated influenza vaccines (LAIV) have been recommended for administration to children. Children are a high-risk group for severe influenza, and a major source of transmission. Therefore, prevention of infection by vaccination is particularly important. However, efficacy and immunogenicity of these vaccines are known to vary by season and geographic location. We compared the immunogenicity of the 2014-2015 Northern Hemisphere trivalent IIV and LAIV against influenza A virus in Canadian Hutterite children aged 2 to 17 using hemagglutination inhibition (HAI) assays, and enzyme-linked immunosorbent assays to measure hemagglutinin-specific serum IgA and mucosal IgA. Both vaccine formulations induced significant increases in HAI titers against H1N1 and H3N2 vaccine strains. Serum IgA titers against H3N2 were significantly boosted by both IIV and LAIV, while only IIV induced a significant increase in serum IgA specific to the H1N1 vaccine strain. While HAI titers correlated with protection conferred by IIV, mucosal IgA titers correlated with protection conferred by LAIV (mucosal IgA titers could not be established as a correlate for IIV due to sample size limitations). IIV and LAIV were previously reported to be equally efficacious in this cohort, although the immunogenicity of IIV was generally superior.