ABSTRACT
Safety and efficacy of adjuvanted vaccines in autoimmune individuals raises growing clinical and scientific interest. Protection from influenza would bring particular benefits in these patients with common cardiac and respiratory impairment. This study evaluates efficacy, clinical safety and immune effects of the administration of a single dose of a virosomal flu vaccine in 46 scleroderma patients. The following parameters were evaluated before and after administration of Inflexal: clinical conditions, inflammation and autoimmunity parameters, humoral response, lymphocyte proliferation and cytokine production upon flu antigen stimulation by specific and non-specific cells. Inflexal was found effective in scleroderma patients. In no subject was worsening of clinical conditions, inflammation and immunological parameters observed.
Subject(s)
Influenza Vaccines/immunology , Scleroderma, Systemic/immunology , Vaccination , Vaccines, Virosome/immunology , Adult , Antibodies, Viral/blood , CD8-Positive T-Lymphocytes/immunology , Cohort Studies , Female , Humans , Lymphocyte Activation , Male , Middle AgedABSTRACT
Vaccination is considered the most effective means of reducing influenza burden, providing substantial benefits in terms of reduction of morbidity, complications, hospitalizations and deaths, even if vaccines have been associated with a reduced immune response and lower effectiveness in older adults, in particular when a mismatch between the vaccine and the circulating virus strains occurred. Several strategies have been proposed to enhance vaccine protection against drifted strains, including the use of adjuvants. Among oil-emulsion adjuvants, MF-59 was approved for human use more than a decade ago and it is largely used for adjuvantation of influenza vaccine. Recent studies have demonstrated that addition of the MF-59 to subunit influenza vaccine can lead to higher haemagglutination-inhibiting seroprotection rates and to higher neutralization antibody titers against drifted strains not included in the vaccine respect to non-adjuvanted vaccine. Promising results were obtained using a new generation of oil-in-water emulsion adjuvants, named AS, offering cross-protection against heterologous challenge in ferrets.
Subject(s)
Adjuvants, Immunologic/administration & dosage , Influenza Vaccines/immunology , Orthomyxoviridae/immunology , Polysorbates/administration & dosage , Squalene/administration & dosage , Antibodies, Viral/blood , Humans , Neutralization Tests , Orthomyxoviridae/classification , VaccinationABSTRACT
Adjuvants enhance antibody response against vaccination. We compared the ability of MF59-adjuvanted and non-adjuvanted subunit influenza vaccines, containing A/Wyoming/3/03(H3N2), to confer cross-protection against four consecutive drifted strains in the elderly. Neutralizing and haemagglutination-inhibiting antibody were measured. MF59-adjuvanted vaccine induced a stronger booster response against A/Panama/2007/99(H3N2) than non-adjuvanted vaccine. A/Panama/2007/99(H3N2) circulated widely during the previous 5 years and was included in vaccines over four consecutive seasons. Broader serological protection against drifted strains that circulated 1 and 2 years after vaccination with A/Wyoming/3/03(H3N2) was observed with MF59-adjuvanted vaccine. Thus, MF59-adjuvanted vaccine confers greater immunogenicity than non-adjuvanted vaccines in vulnerable populations.
Subject(s)
Adjuvants, Immunologic/pharmacology , Influenza A Virus, H3N2 Subtype/immunology , Influenza Vaccines/therapeutic use , Polysorbates/pharmacology , Squalene/pharmacology , Aged , Antibodies, Viral/analysis , Antibodies, Viral/biosynthesis , Cross Reactions , Hemagglutination Inhibition Tests , Humans , Influenza Vaccines/immunology , Middle Aged , Neutralization TestsABSTRACT
Evaluation of the antibody responses induced by the 2004-2005 influenza vaccine strain against the homologous variant, the 2004-2005 field isolates, and a previous circulating strain showed that a correlation between neutralizing and hemagglutination-inhibiting activities exists only when the antigen is very close to the vaccine strain.
Subject(s)
Antibodies, Viral/immunology , Influenza Vaccines/therapeutic use , Orthomyxoviridae/classification , Orthomyxoviridae/immunology , Genetic Drift , Genetic Variation , Hemagglutination Inhibition Tests , Humans , Neutralization Tests , Orthomyxoviridae/genetics , PhylogenyABSTRACT
Although the haemagglutination inhibition assay is considered the "gold standard" for antigenic characterisation of influenza viruses, some limitations of this technique are well known. A new microneutralisation assay, as a tool for antigenic characterisation of influenza B viruses, has been standardised and its performance evaluated in comparison with the haemagglutination inhibition test in the light of molecular characterisation of the haemagglutinin. Twelve B viruses belonging to the two lineages and the four sub-lineages discriminated by phylogenetic analysis of HA were tested. The microneutralisation assay clearly distinguishes viruses belonging to different lineages and, in addition, discriminates strains belonging to different sub-lineages that are poorly or not discriminated using the haemagglutination inhibition test. This new microneutralisation assay could provide a useful tool for antigenic characterisation of circulating influenza viruses and contribute, together with the haemagglutination inhibition test and sequence analysis of the haemagglutinin and neuraminidase, in the choice of the strain for use in vaccine composition.