[Show abstract][Hide abstract] ABSTRACT: We measured haemagglutination inhibiting (HI) serum antibody titers to vaccine matched A/H1N1 influenza virus strain and to the new pandemic 2009 A/H1N1 (pH1N1) virus in two groups of volunteers prior and after 2003/2004 or 2007/2008 influenza seasonal vaccine administration. The responses were examined considering the overall volunteers studied in the two winters (144 and 79, respectively) and grouping those subjects in birth cohort classes (1903–1919; 1920–1957; 1958–1977). Before vaccination, HI antibody titers were found in all the groups examined and, on comparing the different age-groups, titers were higher in the younger groups as compared with the oldest against the A/H1N1 seasonal strains but titers were higher in the oldest as compared with the younger ones against the pH1N1 strain. Vaccination induced significant increases in HI titers against the matched A/H1N1 vaccine strains in all the groups examined. The responses satisfied the EMEA criteria and were higher in the youngest volunteers as compared with older groups. Increases were also found in the level of cross-reactive HI antibodies to the new pandemic 2009 A/H1N1 virus although in most instances the requirements of the EMEA were not met.
Full-text · Article · Dec 2011 · Procedia in Vaccinology
[Show abstract][Hide abstract] ABSTRACT: The surveillance network RotaNet-Italia was established in 2007 in order to investigate the diversity of co-circulating rotavirus strains in Italy, and to provide a baseline for future assessment of possible effects of vaccine implementation in selecting novel versus common rotavirus strains. A total of 2,645 rotavirus strains from pediatric patients with acute diarrhea were collected over three conse-cutive seasons from September 2006 through August 2009, and partially characterized by standardized multiplex RT-PCR. Most of strains (89.1%) belonged to genotypes G1–G4, and G9, associated with either P or P, commonly found in humans worldwide. However, in at least 2.0% of cases, viruses exhibited either a G or P type typical of animal viral strains, sug-gesting gene reassortment events between rotaviruses of different origin. Mixed infections with two or more rotavirus strains were observed frequently (7.6% of patients), and depended on the frequencies of co-circulating rotaviruses of one particular genotype. The numbers and genotypes of likely natural reas-sortants of common genotype rotaviruses were found to be correlated with the observed num-bers and genotypes of mixed infections. Large variation in the relative frequency of different rotavirus genotypes was observed between dif-ferent seasons and/or areas of Italy, suggesting independent evolution or differential introduc-tion of viral strains with respect to both time and space.
Full-text · Article · Jan 2011 · Journal of Medical Virology
[Show abstract][Hide abstract] ABSTRACT: The study evaluated the immunogenicity and efficacy of a trivalent subunit MF59-adjuvanted influenza vaccine (A/Wisconsin/67/05 (H3N2), A/Solomon Islands/3/06 (H1N1) and B/Malaysia/2506/04) in preventing serologically diagnosed infections in a group of 67 institutionalized elderly volunteers during 2007/2008 winter, characterized by co-circulation of drifted A/H3N2, A/H1N1 and B influenza viruses. Influenza vaccination induced a significant increase in the amounts of hemagglutination inhibiting antibodies, both against the vaccine and the epidemic drifted strains. However, vaccination did not prevent the circulation of the new drifted influenza B virus (B/Florida/4/06-like), belonging to the B/Yamagata/16/88-lineage, antigenically and genetically distinct from B/Victoria/2/87-lineage viruses from which the vaccine B strain was derived.
[Show abstract][Hide abstract] ABSTRACT: This study evaluated whether MF59-adjuvanted subunit trivalent influenza vaccine for the 2003/04 winter season (A/Moscow/10/99, H3N2; A/New Caledonia/20/99, H1N1; B/Hong Kong/330/01) would confer protection against mismatched and frequently co-circulating variants of influenza B/Victoria- and B/Yamagata-like virus strains. Haemagglutination inhibiting (HI) antibodies were measured in middle-aged and elderly volunteers against the homologous B/Victoria-like vaccine strain (B/Hong Kong/330/01) and against mismatched B/Victoria-like (B/Malaysia/2506/04) and B/Yamagata-like (B/Singapore/379/99 and B/Shanghai/361/02) strains. Immunization induced significant increases in the amounts of HI antibodies against all influenza B strains under investigation. However, the responses against the heterologous B/Shanghai/361/02 virus did not reach the desirable values of seroprotection. An age-dependent decline of the responses was found for B/Victoria-like antigens, but not for B/Yamagata-like strains. Although further studies are needed, our data support the recommendation of including influenza B viruses of the B/Victoria and B/Yamagata lineages in the future influenza vaccine preparations.
[Show abstract][Hide abstract] ABSTRACT: Concern about the possibility that annually repeated influenza immunizationmayinduce a lower antibody response than first vaccination.
To ascertain the cumulative effects of yearly vaccination on serological response to unaltered vaccine antigens in the elderly.
The haemagglutination-inhibiting (HI) antibody response was examined in 158 elderly institutionalized frail volunteers subdivided in 3 groups according to the sequential winters in which each subject received a trivalent inactivated influenza vaccine. The study, conducted over 5 consecutive winters (from 1998/99 to 2002/03), reports the antibody response only for sequential years (2 or 3) in which the vaccine strain examined was not altered.
Significant increases in the values of HI antibody titres were observed after vaccination in each year examined against the different influenza vaccine strains used, except against B antigen in the second of the 3 winters studied (1999/00). The antibody responses found were not always adequate, i.e. at levels above the currently requested values for commercial vaccines (post-vaccination seroprotection rate >/=1:40, increases in geometric mean titres >/=2, positive responses >/=30% compared with pre-vaccination), probably because of old age (mean age >/=81 years) and the presence of underlying diseases in a high percentage of volunteers (>/=86%). The most frequent chronic diseases found werecardiovascular diseases (48%), endocrine disorders (19%), functional disability (10%) and pulmonary diseases (4%). The post-vaccination values observed in the sequential years were in general similar for A/H3N2 and A/H1N1 vaccine strains. A decrease, however, for some parameters at statistically significant levels, was observed against B antigen following repeated vaccine administrations.
Our data seem to support the possibility of a slight impairment of HI antibody response against unaltered influenza vaccine antigens, especially for influenza strains that have circulated for prolonged periods of time. Indeed a tendency to a lower response was found only against B/Beijing antigen, introduced in the vaccine composition in the winter 1995/96, but not against the A/H3N2 and A/H1N1 vaccine strains, which weremore frequently changed.
[Show abstract][Hide abstract] ABSTRACT: This study examined the antibody response against the three vaccine antigens and the epidemic A/H3N2 drift variant (A/California) and the prevention of laboratory diagnosed influenza infections in a group of elderly institutionalized people vaccinated with the 2004/2005 influenza vaccine. Antibody titres were measured by hemagglutination inhibition (HI) in sera collected before and 1 month after vaccination. Laboratory diagnosis was done examining throat swabs (RT-PCR or MDCK cell culture) or by serology (seroconversion comparing HI titres in sera collected 1 and 5 months after vaccination). Results obtained showed that influenza vaccination induced an adequate immune response against the three vaccine antigens and the epidemic A/H3N2 variant, however it was not capable of preventing an influenza outbreak due to the new A/H3N2 (A/California) variant.
[Show abstract][Hide abstract] ABSTRACT: Flow cytometric analysis, used to study intracellular expression of IFN-gamma in peripheral blood mononuclear cells (PBMC) from aged volunteers before and after parenteral influenza vaccination, was found capable of rapidly detecting influenza antigen induced variation of IFN-gamma expression. Although the vaccine was capable of generating a satisfactory antibody response, it did not stimulate an increase in the percentage of IFN-gamma positive cells.
No preview · Article · Feb 2003 · Developments in biologicals
[Show abstract][Hide abstract] ABSTRACT: To study the decreasing responsiveness of the immune system during aging, influenza virus specific cellular immunity was investigated in a cohort of healthy blood donors between 18 and 70 years of age. The percentage of influenza A virus specific T cells was determined by flow cytometry and found not to change during aging. After stimulation with phorbol 12-myristate 13-acetate and ionomycin, an increase in the percentage of IFN-gamma and IL-4 producing CD8(+) T cells was observed during aging. In addition, the cytotoxic T lymphocyte (CTL) activity was investigated in two additional groups of five donors, 18-20 and 68-70 years of age. The lytic capacity of purified CD8(+) T cells, after in vitro stimulation of peripheral blood mononuclear cells with influenza A virus, seemed lower in 68- to 70-year-old donors than in 18- to 20-year-old donors. Therefore we conclude that the reduced CTL activity in the elderly is not the result of a lower frequency of virus-specific T cells, but more likely the result of impaired antigen-specific proliferation or lower lytic capacity of these cells.
[Show abstract][Hide abstract] ABSTRACT: The World Health Organization (WHO) programme for "Global eradication of Poliomyelitis" established since
1988 has achieved substantial goals, and paralytic poliomyelitis, already eradicatedfrom the Americas, has also become a rare disease in many other parts ofthe world. The goal is realistic and could be reached during thefirst decade of the third millennium.To achieve the certification ofthe eradicàtion of poliomyelitis in a country, it must be verified that no paralytic poliomyelitis due to wild poliovirus occurs over an extended an active surveillance of Acute Flaccid Paralysis (AFP). In ltaly the active AFP surveillance started in 1996 as a
pilot study, and was gradually extended at nationallevel in 1997. The rate of non-polio AFP found was 0.61 cases per 100,000 in 1997 and 0.67 in 1998. The values were lower than the rate of l case per 100,000, in the population aged less than 15 years, considered acceptable by the WHO. However, during the three year survey seven cases of vaccine associated paralytic poliomyelitis (VAPP) were identified and no wild poliovirus was detected. The underestimation of AFP cases in 1997 was particularly due to the delay in organizing the regional hospital network. ln 1998 an improvement of the biologica[ samples collection has been evidenced. This study is the first systematic attempt to determine the rate of AFP in Italy.
Full-text · Article · Jan 2000 · Annali di igiene: medicina preventiva e di comunità
[Show abstract][Hide abstract] ABSTRACT: There is concern about the possibility that sequential influenza vaccination may induce a lower antibody response than first vaccination. The haemagglutination inhibiting antibody response of elderly women (mean age 81 years) after administration of inactivated trivalent influenza vaccine was studied in three (1994-95, 1995-96 and 1996-97, group A, 36 people) or two (1995-96 and 1996-97, group B, 25 subjects) consecutive winters. A satisfactory postvaccination response (i.e. postvaccination significant increase of seroprotected volunteers, seroprotection rate≥60%, mean fold increase of geometric mean titer ≥2 and positive responses ≥30%) was found for volunteers of group B and in the majority of cases for group A. The comparison of the results among the different years studied evidenced a prevalently unimpaired response after repeated vaccine administration. A modest reduction in the antibody induction was found in group A against A (H1N1) and B antigens in the last year studied. These findings suggest that the current recommendation for annual vaccination of elderly persons can be regarded as appropriate.
[Show abstract][Hide abstract] ABSTRACT: The last case of poliomyelitis due to transmission of indigenous wild poliovirus occurred in Italy in 1982. To achieve the certification of the eradication of poliomyelitis in Italy, an active surveillance of acute flaccid paralysis (AFP) in the population aged less than 15 years was set up following the World Health Organization (WHO) guidelines. The survey started in 1996 with a pilot study involving 4 out of 21 regions, and was gradually extended to a national level in 1997. The two-year survey identified five patients with diagnosis of vaccine associated paralytic poliomyelitis (VAPP). Polioviruses type 2 and 3 Sabin-like were isolated and characterized in three of them. In the remaining two cases, samples were collected late after the onset of symptoms, and poliovirus could not be isolated. No wild polioviruses were detected during the survey. The rate of non-polio AFP found in Italy in 1997 was 0.61 cases per 100,000, which is lower than the level of 1.0 case per 100,000 considered as acceptable by the WHO. This was mainly due to the delay in organizing the hospital network and starting the active search of AFP cases in the largest and most densely populated regions. Therefore, the overall rate of AFP found in Italy underestimates the global effectiveness of the program, which however will be better evaluated in the next few years. This study is the first systematic attempt to determine the rate of AFP in Italy.
Full-text · Article · Jan 1999 · European Journal of Epidemiology
[Show abstract][Hide abstract] ABSTRACT: The humoral response (haemagglutination inhibiting antibodies) to trivalent split influenza vaccine for the 1993-94 winter season (A/Beijing/32/92 (H3N2), A/Singapore/6/86 (H1N1) and B/Panama/45/90) was evaluated in a group of young HIV-seropositive ex-intravenous heroin users and compared with responses measured in HIV-seronegative individuals with a similar history. HIV-negative volunteers showed an overall positive response suggesting that previous heroin use did not influence their humoral response to influenza vaccine. Comparable results were obtained in HIV-positive subjects with CD4+ lymphocyte counts > 500 microliters-1, whereas impaired reactivity was found in HIV-positive volunteers with CD4+ counts < 500 microliters-1. Booster vaccination did not increase antibody levels in any of the groups studied, although the data did not exclude a positive influence of a second vaccine dose on persistence of antibody at 120 days after the first dose. No significant changes were observed in p24 antigenemia levels in HIV-positive individuals after vaccination.
[Show abstract][Hide abstract] ABSTRACT: Interferon (IFN) treatment of target cells can alter their susceptibility to natural resistance (NR), evidenced as in vitro 'natural killer' (NK) cell-mediated lysis or as in vivo rapid cell clearance. This paper reports the consequence of direct in vitro treatment with IFN-alpha/beta or IFN-gamma on acute rejection of leukemia cells in lethally irradiated hosts. This type of rejection has the characteristics of NR, although it is specific and genetically regulated. The data were obtained injecting intravenously FLC (FLC-745 and FLC-3C18 clones; H-2d) and EL-4 (H-2b) leukemia lines in lethally irradiated syngeneic mice and evaluating proliferation 4 days later by 125IUdR uptake. Overnight pretreatment with 100 U/ml of IFN-gamma protected tumor cells from NR-induced rejection in mice. This was evident by higher 125IUdR incorporation in spleens of mice inoculated with IFN-gamma pretreated leukemia cells, as compared to that detected in the spleens of hosts injected with untreated cells, in mice with high levels of NR, but not in hosts depressed for NR. Treatment with 1,000 U/ml of IFN-alpha/beta induced protection only of FLC-745 cells, injected in Poly I:C stimulated hosts. On the other hand, a lower 125IUdR uptake after IFN-alpha/beta incubation, as compared with control cells, was evidenced with FLC-745 and EL-4 lines inoculated in mice with normal or depressed NR. The IFN-induced alterations of leukemia cells to in vivo NR susceptibility were not associated with substantial changes of binding ability to NR effectors or of MHC-antigen expression.
No preview · Article · Jan 1993 · Natural Immunity
[Show abstract][Hide abstract] ABSTRACT: The immunogenicity of inactivated whole trivalent influenza vaccines (A/Taiwan/1/86 (H1N1), A/Sichuan/2/87 (H3N2), and B ijing/1/87) recommended for the 1988-89 winter season was evaluated in 236 elderly (mean age 71 years) high risk volunteers. An overall significant increase in the number of subjects with protective haemagglutination inhibiting (HI) antibodies (titer > 1:40) against vaccine components was observed after vaccination. Nevertheless, a percentage of individuals (ranging from 56% to 62%) remained without protective antibodies and the number of people showing a positive response was limited (from 32% to 41%). By the comparative analysis of the results obtained examining the presence of protective levels of antibody in the sera from 91 volunteers using HI versus the single radial haemolysis (SRH) test, we obtained evidence for a higher sensitivity of SRH technique especially against B antigen.
No preview · Article · Jul 1992 · European Journal of Epidemiology
[Show abstract][Hide abstract] ABSTRACT: Trivalent split or subunit influenza vaccines [A/Shangai/11/87 (H3N2), A/Singapore/6/86 (H1N1) and B/Yamagata/16/88] recommended for the 1989-90 winter season and licensed in Italy, were administered to 149 volunteers of three different age groups (elderly, middle-aged and young). Antibody production was determined in pre- and postvaccination sera by haemagglutinin inhibition test and the results were evaluated as protection and response rates. The split vaccine was more immunogenic than the subunit preparation, especially against the B virus strain. Age had no obvious impact on the degree of responsiveness to vaccination.
[Show abstract][Hide abstract] ABSTRACT: The antibody response (determined using the single radial haemolysis in gel technique) to inactivated whole-virion trivalent influenza vaccine [A/Leningrad/360/86(H3N2), A/Taiwan/5/87 and B/Ann Arbor/1/86], recommended for the 1987-88 winter season in Italy, in 49 elderly (age greater than or equal to 60 years) subjects was compared with the response in 23 young adult (age less than 60 years) volunteers. The subjects were prevalently healthy and a high percentage of young and old people had been repeatedly immunized against influenza in previous years. No significant differences were detected among age groups; moreover, the immune response measured by seroconversion or by a significant rise in antibody titre was constantly low.
[Show abstract][Hide abstract] ABSTRACT: Experiments were designed to test the presence of antitumor natural resistance (NR) in DBA/2 mice against highly oncogenic in vivo passaged histocompatible Friend leukemia cells (FLC-V). NR was measured in vivo as rapid clearance of radiolabeled cells from different organs or as growth inhibition in lethally irradiated mice. Interferon-sensitive (745) or interferon-resistant (3C18) lines were used. Organ clearance studies showed that young recipients eliminate cells more rapidly than old mice. Moreover, depressive (e.g., cyclophosphamide or carrageenen) or enhancing (e.g., poly (I:C) or Friend leukemia virus infection) agents of NR function modulate accordingly leukemia cell clearance. Similar results were obtained testing tumor growth in lethally irradiated hosts, although modulating agents were substantially less effective in this system. Both FLC-745-V and FLC-3C18-V lines were equally susceptible to NR. Therefore, these data provide further support to the hypothesis that exogenous IFN capable of suppressing the growth of both lines could act via enhancement of the NR function.
No preview · Article · Mar 1989 · Cellular Immunology
[Show abstract][Hide abstract] ABSTRACT: Natural resistance has been detected in lethally irradiated C57Bl/6 (B6) mice inoculated intravenously with the ascites form of a syngeneic B6 leukemia. EL-4 cells were injected into lethally irradiated (800 R) B6 mice and tumor cell proliferation was evaluated by 125IUdR uptake in different organs 4 days after the challenge. Differential growth of lymphoma cells was observed when young mice were injected as compared with older mice and when mice were treated with agents known to interfere with natural resistance (e.g., poly(I:C), FLV-P, carrageenan, cyclophosphamide, high doses of irradiated cells). Similar results were obtained by measuring rapid clearance of 125IUdR-labeled EL-4 cells from lungs of intact B6 mice. In vivo cold competition studies, employing EL-4 and several other tumor lines of the same or different haplotype, showed that only EL-4 and RBL-5 cells were capable of inhibiting syngeneic resistance against EL-4 tumor. On the contrary, YAC-1 lymphoma cells, the most susceptible target to natural killer-mediated cytotoxicity in vitro, did not compete. These results suggest that EL-4 cells express membrane determinants not detectable on normal H-2b parental bone marrow cells and are susceptible to natural resistance against hemopoietic tumor cells in lethally irradiated syngeneic B6 mice.
No preview · Article · Sep 1987 · Cellular Immunology