Immunogenicity of modified vaccinia virus Ankara expressing the hemagglutinin stalk domain of pandemic (H1N1) 2009 influenza virus.

BACKGROUND: Vaccination offers protection against influenza, although current vaccines need to be reformulated each year. The development of a broadly protective influenza vaccine would guarantee the induction of heterosubtypic immunity also against emerging influenza viruses of a novel subtype. Vaccine candidates based on the stalk region of the hemagglutinin (HA) have the potential to induce broad and persistent protection against diverse influenza A viruses. METHODS: Modified vaccinia virus Ankara (MVA) expressing a headless HA (hlHA) of A/California/4/09 (CA/09) virus was used as a vaccine to immunize C57BL/6 mice. Specific antibody and cell-mediated immune responses were determined, and challenge experiments were performed by infecting vaccinated mice with CA/09 virus. RESULTS: Immunization of mice with CA/09-derived hlHA, vectored by MVA, was able to elicit influenza-specific broad cross-reactive antibodies and cell-mediated immune responses, but failed to induce neutralizing antibodies and did not protect mice against virus challenge. CONCLUSION: Although highly immunogenic, our vaccine was unable to induce a protective immunity against influenza. A misfolded and unstable conformation of the hlHA molecule may have affected its capacity of inducing neutralizing antiviral, conformational antibodies. Design of stable hlHA-based immunogens and their delivery by recombinant MVA-based vectors has the potential of improving this promising approach for a universal influenza vaccine.

Partial Protection Induced by 2011-2012 Influenza Vaccine Against Serologically Evidenced A(H3N2) Influenza Virus Infections in Elderly Institutionalized People.

Ninety-two institutionalized elderly subjects were vaccinated with trivalent influenza inactivated vaccine available for the 2011-2012 season, characterized by a prevalent circulation of A(H3N2) influenza viruses (A/Victoria/208-clade) presenting antigenic and genetic patterns different from the A(H3N2) vaccine component (A/Perth/16/2009-clade). Haemagglutination inhibiting (HI) antibody titers were determined in sera collected before, 1 and 6 months after vaccination and patients were considered positive for serological evidence of recent infection if they had a seroconversion on comparing HI titers found in sera collected 1 and 6 months after vaccination. No seroconversions were found against A(H1N1) and B vaccine components. Instead 17 volunteers seroconverted against all or at least some of the different A(H3N2) antigens examined, i.e. the 2011-2012 (A/Perth/16/2009) and the 2012-2013 (A/Victoria/361/2011) vaccine strains and four drifted viruses belonging to the A/Victoria/208-clade circulating in the area were the elderly people were living. The results obtained suggest that influenza infections in the vaccinated volunteers might be due both to a poor match between vaccine and circulating A(H3N2) viruses, since 1 month after vaccination 15 of the 17 volunteers had post-vaccination HI titers considered protective (≥40) against the A(H3N2) vaccine antigen, but not always against the epidemic strains, and to a waning of vaccine induced immune response, since 6 months after vaccination HI titers of non-infected volunteers were found to be decreased as compared with those found 1 month after vaccination.

Immunogenicity of intramuscular MF59-adjuvanted and intradermal administered influenza enhanced vaccines in subjects aged over 60: A literature review.

Because of the age-related immune system decline, 2 potentiated influenza vaccines were specifically licensed for the elderly: Fluad(®), an MF59-adjuvanted vaccine administered intramuscularly (IM-MF59), and Intanza 15 mcg(®), a non adjuvanted vaccine administered intradermally (ID). The objective of this paper was to conduct a systematic review of studies that evaluated antibody responses in the elderly following immunization with IM-MF59 or ID vaccines. The two potentiated vaccines induced immune responses satisfying, in most instances, the European Medicine Agency immunogenicity criteria, both against vaccine antigens and heterovariant drifted strains. Considering pooled data reported in the articles analyzed and papers directly comparing the 2 vaccines, the antibody responses elicited by IM-MF59 and ID were found to be generally comparable. The use of IM-MF59 and ID vaccines can be proposed as an appropriate strategy for elderly seasonal influenza vaccination although further studies are required for a more complete characterization of the 2 vaccines.

Antibody responses to intradermal or intramuscular MF59-adjuvanted influenza vaccines as evaluated in elderly institutionalized volunteers during a season of partial mismatching between vaccine and circulating A(H3N2) strains.

BACKGROUND: The age-related weakening of the immune system makes elderly subjects less responsive to influenza vaccination. In the last years, two "enhanced vaccines" were licensed for individuals aged ≥65 years, one being a subunit vaccine (Fluad®) containing the MF59 adjuvant administered intramuscularly (IM-MF59) and the other one a split non-adjuvanted vaccine administered intradermally (Intanza® 15mcg) (ID). In the present study, we evaluated and compared the antibody responses against the three vaccine antigens and heterovariant A(H3N2) circulating viruses induced by IM-MF59 and ID influenza vaccines in 80 elderly institutionalized volunteers (40 per group) during the Winter season 2011-2012. RESULTS: Hemagglutination inhibiting (HI) antibody titers were assessed in blood samples collected before, 1 and 6 months after vaccination. One month after vaccination both the IM-MF59 and ID vaccines induced increases in HI titers against all the three vaccine strains. The results in the two groups were similar against the A(H3N2) and A(H1N1) strains. Responses against the B strain typically tended to be higher after ID than IM-MF59, yet both vaccines stimulated lower responses against the B strain than against the two A strains. The two vaccines induced favorable results also against four epidemic drifted A(H3N2) viruses circulating in Winter 2011-2012. Six months after vaccination, the HI titers decreased in both groups. CONCLUSION: The responses induced by IM-MF59 and ID vaccines in institutionalized elderly people were similar against the A(H3N2) and A(H1N1) strains but frequently higher, for the ID, against the B strain. The two vaccines induced positive responses against drifted A(H3N2) circulating viruses.

An Observational Retrospective Study Provide Information on Hospitalization and Severe Outcomes of the 2009 A(H1N1) Infection in Italy.

BACKGROUND: The aim of this study was to try to ascertain whether, in the absence of a pre-organized programme, locally collected data might provide information about the epidemiological and clinical characteristics of the recent A(H1N1) pandemic in Italy. METHODS: The study was an observational retrospective analysis of the clinic-epidemiological features performed by reviewing medical charts from 141 hospitalized patients with laboratory confirmed pandemic A(H1N1) infection in Umbria, a region of central Italy, in the period July 2009 to March 2010. RESULTS: The pandemic virus was found capable of inducing severe illness requiring hospitalization or intensive care unit admission (ICU), or resulting in death. Age and comorbidity were found to be potential risk factors for severe disease. The mean age of the hospitalized patients was 37 years (range 0 - 93 yrs), however the mean age of ICU admitted patients, including people who did not survive, was higher as compared with those admitted to general medical ward (54 vs 35 yrs). The highest incidence of hospitalization was observed in the youngest group (0 - 17 yrs), the greatest rate of ICU admission in adults (18 - 64 years), and the risk of death in the oldest population (≥ 65 yrs). Comorbity conditions were present in some (55%), but not all hospitalized patients and increased with the age and the severity of the illness. CONCLUSIONS: The data obtained are compatible with the identified epidemiological characteristics of the A(H1N1) pandemic derived from partial information previously collected in Italy and from studies conducted in other European and non European countries. The results of our retrospective observational study suggest that locally organized data collection may give information on the epidemiological and clinical characteristics of a pandemic that are compatible with those obtained from more complex and complete studies.

Clinical validation of a new algorithm for computerized dosing of vitamin K antagonist therapy: a retrospective simulation study.

The number of patients on oral anticoagulant therapy has increased in recent years, and this trend is expected to continue. The increased workload for physicians has led to the development of computerized systems to make organizational workflow more efficient. These programs may include algorithms to propose a weekly dosage and timing for the following visit. Before introducing a new algorithm in clinical practice, its safety and efficacy must be validated. We undertook a retrospective simulation study to test a new algorithm for the TAOnet system. The main outcome was the percentage of concordant and discordant proposals between manual- and algorithm-based prescriptions. Pairs of computerized and physician prescriptions were assessed. They were categorized as 0.1-5, 5.1-10 and >10% if the dose was different, and assigned as "algorithm better" or "manual better" dependent upon the subsequent international normalized ratio value. In 61.0% of cases, the manual and computerized weekly dosage assignments were identical; in 15.3% of cases, the difference was between 0.1 and 5%; in 14.7 of cases, it was between 5.1 and 10%; and in 9.0% of cases, it was >10%. The algorithm did better in 43.9% of discordant pairs, generally due to less frequent under-dosing. In conclusion, the new algorithm proved to consistently overlap with the manual method. The algorithm is useful but must be tested in a multi-center, prospective, interventional study.

Influenza viruses and cross-reactivity in healthy adults: humoral and cellular immunity induced by seasonal 2007/2008 influenza vaccination against vaccine antigens and 2009 A(H1N1) pandemic influenza virus.

We analyzed humoral and cellular immune responses against vaccine antigens and the new A(H1N1) virus in healthy adults before and after immunization with the 2007/2008 commercially available trivalent subunit MF59-adjuvanted influenza vaccine during the Fall 2007, prior to the emergence of the new virus. Antibody titers were significantly boosted only against the three vaccine antigens. Seasonal vaccination boosted pre-existing cellular responses upon stimulation of peripheral blood mononuclear cells not only with the homologous three vaccine antigens, but also with the heterologous new 2009 A(H1N1) and with a highly conserved peptide present in the stalk region of hemagglutinin (HA). These results show that cross-reactive cell responses against the new virus were present before the circulation of the virus and were boosted by seasonal vaccination. The cross-reactivity of cellular responses might, at least in part, explain the low pathogenicity of the new pandemic virus. The finding of cellular immunity, that can be increased by seasonal vaccination, against the conserved HA peptide, underline the potential use, in human vaccines, of conserved peptides of the stalk region of HA characterized by broad immunogenicity in experimental systems.

Influenza vaccination and vitamin K antagonist treatment: a placebo-controlled, randomized, double-blind crossover study.

BACKGROUND: Among millions of persons vaccinated against influenza virus each year, many are older patients treated with several drugs, including vitamin K antagonists (VKAs), among which warfarin is the most commonly used. Due to high interpatient and intrapatient variability, the therapeutic dose of VKA has to be individualized by monitoring of international normalized ratio (INR) values. The objectives of this study were to evaluate variation in the INR and warfarin weekly dose variation after influenza vaccination administration and to follow up patients for related hemorrhagic and thrombotic events to evaluate the safety of the influenza vaccine and to assess the immunogenicity of the influenza vaccination in patients receiving VKAs. METHODS: One hundred four patients on a stable VKA regimen and with an indication for influenza vaccination were randomized to receive influenza vaccination and subsequent placebo administration, or vice versa. All patients were tested for coagulation variables, clinical events, and antibody response against vaccine components. RESULTS: Similar mean prothrombin times, expressed as the INR and VKA weekly dose, were found in patients after receiving vaccine or placebo. The absence of any vaccination effect on VKA treatment was confirmed using a linear mixed-effects model. The percentages of time that patients were in therapeutic range were 70.7% after receiving vaccine and 72.4% after receiving placebo (P = .57). There were no fatal or major bleeding events and 11 minor mucocutaneous hemorrhagic events. After vaccination, the percentage of seroprotected patients ranged from 92.0% to 100.0% depending on the vaccine antigen examined. CONCLUSIONS: Influenza vaccination had no significant effect on INR values or warfarin sodium weekly doses. Close monitoring of INR values is not required after influenza vaccination in patients on stable long-term VKA regimens. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00222638.

Comparison of the BD Phoenix system with the cefoxitin disk diffusion test for detection of methicillin resistance in Staphylococcus aureus and coagulase-negative staphylococci.

The BD Phoenix system was compared to the cefoxitin disk diffusion test for detection of methicillin (meticillin) resistance in 1,066 Staphylococcus aureus and 1,121 coagulase-negative staphylococcus (CoNS) clinical isolates. The sensitivity for Phoenix was 100%. The specificities were 99.86% for S. aureus and 88.4% for CoNS.

Audit of the clinical use of fresh-frozen plasma in Umbria: study design and results of the pilot phase.

BACKGROUND: Fresh-frozen plasma (FFP) is unanimously recognised by international guidelines as the blood component of choice for the management of acute haemorrhage when accompanied by disorders of haemostasis, for disseminated intravascular coagulation in the presence of haemorrhage, for rare bleeding disorders when specific clotting factor concentrates are not available and for thrombotic thrombocytopenic purpura. The literature, however, reports a high percentage of inappropriate requests for FFP. This article presents the results of a pilot study of clinical auditing of the use of FFP in the Region of Umbria (Italy). METHODS: This study was based on the examination of the requests for FFP made in April 2006 to four Immunotransfusion Services (ITS) in Umbria and of the clinical records of the patients receiving transfusions. The following indicators were identified and evaluated: completeness of the request, appropriateness of the indication and the dose, completeness of the records in the clinical charts, adverse events, in-hospital morbidity and mortality, efficacy of the treatment (evaluated by analysing the changes between pre- and post-transfusion coagulation test results) and, as an indicator of the process, the correspondence between data in the paper request form and in the computerised database. The data were extracted from the ITS databases, from the paper request forms and from the patients' clinical records. RESULTS: Two hundred and twenty-one requests (615 units of FFP) for 109 patients and 92.8% of the related clinical records were examined. The patients were admitted in medical (22.9%), surgical (51.4%) and critical care units (25.7%). In 50.7% of the cases, the completeness of the data in the individual requests was good (65-80% of the fields filled in). The indication was appropriate in 31.5% of the requests evaluated (56.1% of the total), with no difference related to different requesters. The dosage was appropriate in 62.7% of the requests evaluated (62% of the total). A comparison of pre- and posttransfusion laboratory data showed a significant correction of pathological values (p=0.02) only for the International Normalised Ratio (INR). CONCLUSIONS: Critical areas that should be targeted by interventions to improve plasma usage are those related to the appropriateness of the indication, the completeness of the data entered in the request forms and the data recorded in the clinical charts.

The good use of plasma. A critical analysis of five international guidelines.

BACKGROUND: The clinical use of fresh-frozen plasma (FFP) is progressively increasing both nationally and internationally, despite the fact that many studies have shown the weaknesses of the indications for its use. Guidelines on the good use of plasma have, therefore, been adopted in various countries. The aim of the present study was to analyse some of the existing guidelines on the good use of plasma, applying a scientifically validated method, as a preliminary step in the implementation of Regional guidelines. METHODS: Abibliographic search (1990-2006) was conducted in databases, websites, and the archives of scientific societies. Relevant articles were recovered in full. The selected guidelines were evaluated using theAGREE instrument, which assesses the completeness and structural quality of the guidelines and, in some aspects, the contents of the recommendations. The project, co-ordinated by the Regional Centre for Co-ordination and Compensation (CRCC) and carried out by four Services of Immunohaematology and Transfusion (SIT) in Umbria, was funded by the Region of Umbria and approved by the four health care institutions involved. RESULTS: The bibliographic search yielded 3067 abstracts of which 239 were considered relevant. The analysis of these led to the recovery of 11 guidelines, among which five were selected: those from the British Committee for Standards in Haematology, theAgence Française de Securité Sanitaire de Produits de Sante, the Canadian Members of the Expert Working Group, the American Society of Anesthesiologists Task Force on Blood Component Therapy and the National Health and Medical Research Council (NHMRC)/Australasian Society of Blood Transfusion. CONCLUSIONS: None of the guidelines analysed obtained a score higher than 50% in all the domains of the AGREE score. There was no evidence of a tendency to improvement over time in the guidelines analysed. Objective evaluation of the guidelines analysed could provide the starting point for the subsequent production of similar documents.

[Preliminary survey of human intestinal parasitosis in a Peruvian Andean zone]. / Sondaggio preliminare copro-parassitologico in una zona andina del Perù.

We studied 91 faecal specimens of 38 children and 53 adults in a five-day epidemiological survey between the end of February and the beginning of March, 2006. The subjects were in- or out-patients of Chacas Hospital, Ancash. The O&P were performed with macroscopic evaluation, microscopic (direct and after formalin-ether concentration, FEA) observations and Giemsa permanent stain of all faecal samples. 61 subjects (67.0%) were infected with parasites (25 children, 65.5%, and 36 adults, 67.9%). D. fragilis was prevalent in 30.8% of subjects (28.9% of children, 32.1% of adults); G. duodenalis was observed in 12.1% of cases (21.1% of children and 5.7% of adults); A. lumbricoides was observed in 15.4% of cases (18.4% and 19.9% respectively); other helminths were identified in 7.7% of cases (10.1% and 5.7% respectively); non-pathogenic protozoa alone were observed in 23.1% of cases (28.9% among children and 19.9% among adults). D. fragilis was more frequent among females (44.7% vs. 20.8%), while G. duodenalis and A. lumbricoides among males (13.2% vs. 10.5% and 17.0% vs. 13.2% respectively). We emphasize the usefulness of both FEA and Giemsa permanent stain for a good O&P.