Influenza Vaccine Type-Dependent Antibody Response in Patients with Autoimmune Inflammatory Rheumatic Diseases

BACKGROUND: The study aimed to explore influenza antibody response in patients with autoimmune inflammatory rheumatoid diseases (AIIRDs) stratified by the different vaccine types applied in Denmark during the 2018-2019 influenza season.METHODS: Included patients were diagnosed with rheumatoid arthritis, psoriatic arthritis, or spondyloarthritis receiving biological disease-modifying antirheumatic drugs (bDMARDs) with or without conventional synthetic disease-modifying antirheumatic drugs. Influenza vaccination status in the 2018-2019 season and vaccine type received were reviewed in the Denmark. Blood samples were drawn ≥ 14 days post vaccination, and antibody titers were determined by the hemagglutinin inhibition (HAI) assay for the serotypes A/Michigan/H1N1, A/Singapore/H3N2, and B/Colorado included in the influenza vaccines in the 2018-2019 season. An overall serotype HAI geometric mean titer (GMT) was calculated from the 3 serotype-specific HAI titers. An overall serotype HAI GMT ≥ 40 was considered protective.RESULTS: Of the 205 included patients, 105 (51%) had received influenza vaccination. One-quarter of vaccinated patients achieved post-vaccination overall serotype HAI GMT ≥40. For patients vaccinated with Influvac, a significantly higher proportion had HAI titers ≥ 40 for 2 serotypes, namely, A/Michigan/H1N1 and A/Singapore/H3N2, than patients vaccinated with Vaxigrip or VaxigripTetra. The same applied to all serotypes HAI GMT, where significantly more patients who received Influvac achieved postvaccination HAI GMT≥40 versus patients who received Vaxigrip (p=0.02) or VaxigripTetra (p=0.002). The latter outcome was explored in a multivariable logistic regression analysis and remained significant when including the following variables: age, sex, treatment with methotrexate and/or prednisolone, type of influenza vaccine, time interval from vaccination to antibody measurement, and previous vaccination status.CONCLUSION: Influenza antibody levels following vaccination with Influvac in bDMARD-treated patients with AIIRDs were superior to Vaxigrip and VaxigripTetra. Treatment with methotrexate (MTX) did not reduce the antibody response.</p

Influenza A Virus with a Human-Like N2 Gene Is Circulating in Pigs

A novel reassortant influenza A virus, H1avN2hu, has been found in Danish swine. The virus contains an H1 gene similar to the hemagglutinin (HA) gene of H1N1 avian-like swine viruses and an N2 gene most closely related to the neuraminidase (NA) gene of human H3N2 viruses from the mid-1990s

A Novel Prophylaxis Strategy Using Liposomal Vaccine Adjuvant CAF09b Protects against Influenza Virus Disease

The SARS-CoV-2 pandemic caused a massive health and societal crisis, although the fast development of effective vaccines reduced some of the impact. To prepare for future respiratory virus pandemics, a pan-viral prophylaxis could be used to control the initial virus outbreak in the period prior to vaccine approval. The liposomal vaccine adjuvant CAF®09b contains the TLR3 agonist polyinosinic:polycytidylic acid, which induces a type I interferon (IFN-I) response and an antiviral state in the affected tissues. When testing CAF09b liposomes as a potential pan-viral prophylaxis, we observed that intranasal administration of CAF09b liposomes to mice resulted in an influx of innate immune cells into the nose and lungs and upregulation of IFN-I-related gene expression. When CAF09b liposomes were administered prior to challenge with mouse-adapted influenza A/Puerto Rico/8/1934 virus, it protected from severe disease, although the virus was still detectable in the lungs. However, when CAF09b liposomes were administered after influenza challenge, the mice had a similar disease course to controls. In conclusion, CAF09b may be a suitable candidate as a pan-viral prophylactic treatment for epidemic viruses, but must be administered prior to virus exposure to be effective.publishedVersio