Vaccine strain affects seroconversion after influenza vaccination in COPD patients and healthy older people.

Though clinical guidelines recommend influenza vaccination for chronic obstructive pulmonary disease (COPD) patients and other high-risk populations, it is unclear whether current vaccination strategies induce optimal antibody responses. This study aimed to identify key variables associated with strain-specific antibody responses in COPD patients and healthy older people. 76 COPD and 72 healthy participants were recruited from two Australian centres and inoculated with influenza vaccine. Serum strain-specific antibody titres were measured pre- and post-inoculation. Seroconversion rate was the primary endpoint. Antibody responses varied between vaccine strains. The highest rates of seroconversion were seen with novel strains (36-55%), with lesser responses to strains included in the vaccine in more than one consecutive year (27-33%). Vaccine responses were similar in COPD patients and healthy participants. Vaccine strain, hypertension and latitude were independent predictors of seroconversion. Our findings reassure that influenza vaccination is equally immunogenic in COPD patients and healthy older people; however, there is room for improvement. There may be a need to personalise the yearly influenza vaccine, including consideration of pre-existing antibody titres, in order to target gaps in individual antibody repertoires and improve protection.

Whole transcriptome analysis of high and low IFN-α producers reveals differential response patterns following rhinovirus stimulation.

OBJECTIVES: Viral respiratory infections cause considerable morbidity and economic loss. While rhinoviruses (RV) typically cause little more than the common cold, they can produce severe infections and disease exacerbations in susceptible individuals, such as those with asthma. Variations in the regulation of key antiviral cytokines, particularly type I interferon (IFN-α and IFN-ß), may contribute to RV susceptibility. To understand this variability, we compared the transcriptomes of high and low type I IFN producers. METHODS: Blood mononuclear cells from 238 individuals with or without asthma were cultured in the presence or absence of RV. Those samples demonstrating high or low RV-stimulated IFN-α production (N = 75) underwent RNA-sequencing. RESULTS: Gene expression patterns were similar in samples from healthy participants and those with asthma. At baseline, the high IFN-α producer group showed higher expression of genes associated with plasmacytoid dendritic cells, the innate immune response and vitamin D activation, but lower expression of oxidative stress pathways than the low IFN-α producer group. After RV stimulation, the high IFN-α producer group showed higher expression of genes found in immune response biological pathways and lower expression of genes linked to developmental and catabolic processes when compared to the low IFN-α producer group. CONCLUSIONS: These differences suggest that the high IFN-α group has a higher level of immune system readiness, resulting in a more intense and perhaps more focussed pathogen-specific immune response. These results contribute to a better understanding of the variability in type I IFN production between individuals.