Immunogenicity of influenza vaccination in patients with non-Hodgkin lymphoma.

PURPOSE: The purpose of this study was to assess humoral response to influenza vaccine in patients (pts) with non-Hodgkin lymphoma (NHL) as compared to healthy subjects (ctrl). PATIENTS AND METHODS: In two epidemic seasons, 2003/2004 and 2004/2005, 163 pts and 92 ctrl were vaccinated. Antibody titers to hemagglutinin (HA) and neuraminidase (NA) were measured in serum samples collected before vaccination, and 1 and 6 months apart. Changes in antibody titers were assessed by comparing geometric mean titers (GMT), mean fold increases (MFI), and seroprotection and seroresponse rates to baseline values. RESULTS: Pts vaccinated in 2003/2004 had, after 1 month, increase in GMT by a factor of 8.64-26.60 for antihemagglutinin antibodies (HI) and 6.93-12.66 for antineuraminidase antibodies (NI), as compared to factor of 9.12-24.41 for HI and 4.83-10.31 for NI in ctrl. At 1 month after vaccination, seroprotection and seroresponse rates were similar in both groups, ranging from 68.42 to 84.21% and 71.93 to 94.74% in NHL, and 66.67-82.22% and 62.22-86.67% in ctrl, respectively. Pts vaccinated in 2004/2005 had increase in the GMT by a factor of 38.76-41.49 for HI and 26.59-30.31 for NI, as compared to factor of 81.19-104.32 for HI and 52.16-54.52 for NI in ctrl. Seroprotection and seroresponse rates were lower in the former group, ranging from 62.11 to 65.26% and 74.47 to 77.66%, respectively. In both seasons, pts achieved titres of antibodies greater than the protective threshold, irrespective of the previous chemotherapy administration. CONCLUSIONS: The results indicate that influenza vaccination induces sufficient immune response in pts with NHL, irrespective of previous chemotherapy.

[Various sides of influenza, part I--structure, replication, changeability of influenza viruses, clinical course of the disease, immunological response and laboratory diagnostics]. / Grypa w róznych aspektach. Czqsc I--Budowa, replikacja i zmiennosc wirusów grypy oraz przebieg kliniczny choroby, odpowiedz immunologiczna i diagnostyka laboratoryjna.

Influenza viruses represent Orthomyxoviridae family. Spherical virions are 80-120 nm in diameter and have two-layer lipid envelope. The following proteins are coded by 8 or 7 segments of the single-stranded RNA: nucleoprotein (NP), polymerase PB2, PB1 and PA, member protein--M1 and M2, glycoproteins--hemagglutinin (HA) and neuraminidase (NA). HA and NA form spikes on the virion surface. On the basis of antigenic differences there are distinguished three types of influenza virus-A, B and C. Besides, influenza A viruses occur in different subtypes, depending on the features of HA and NA. One of influenza characteristics is its antigenic changeability: antigenic drift and antigenic shift. Infection occurs by droplet route, sometimes through direct contact with infected person or surface. Influenza virus attacks epithelial cells of upper respiratory tract, where replication takes place resulting in the production of approximately 1000 of progeny virions during a single 6-12 h cycle in one cell. Necrosis of ciliary cells of mucosa facilitates invasion of bacterial pathogens. Incubation period lasts on average 1-2 days. Influenza illness without complications characterizes the sudden onset of respiratory symptoms and systemic symptoms. Regression of symptoms usually occurs after 3-5 days, but cough and malaise may be observed for over 2 weeks. Reasons for the severe course of the disease or even death are post-influenza complications, e.g. viral pneumonia and bronchitis, bronchiolitis in children, secondary bacterial pneumonia, otitis media, myocarditis and pericarditis, Reye's syndrome, myositis, myoglobinuria, neurological complications and exacerbation of existing chronic diseases. In the case of influenza there is no possible to make the unquestionable diagnosis only on the basis of clinical picture of the disease. Therefore in some circumstances there is important to make some diagnostic laboratory tests as RT-PCR, immunofluorescence assay or isolation of virus and detection of the specific antibodies. The main determinants of the immunity to influenza virus infection are antihemagglutinin (anti-HA) antibodies and antineuraminidase antibodies (anti-NA). The former play fundamental role for the protection against the infection, while anti-NA antibodies limit virus spreading and contribute to a milder course of the disease. In the response to influenza infection there are observed serum immunoglobulines IgG and IgM (after the first contact with the antigen), while immunoglobulines IgA are produced rarely. The latter are produced locally in the high concentrations on the mucus of respiratory tract. Cellular immunological response is important for recovery from influenza where a significant role of cytotoxic T lymphocytes should be emphasized. These lymphocytes are able to kill infected cells in the earliest phases of replication before the progeny virions are formed.

[Various sides of influenza. Part II--epidemiology, influenza surveillance and prophylaxis]. / Grypa w róznych aspektach. Czqsc II--Epidemiologia i nadzór nad grypq oraz profilaktyka.

Influenza viruses cause epidemics and pandemics. Animal reservoir for influenza viruses and repeatedly occurring human infections with avian influenza viruses since 1997 indicate that there is a real threat of pandemic, but it is no possible to predict when this outbreak begins. Every year 330-990 millions of people are ill due to influenza worldwide. In Poland there are registered from a few hundred to few millions of cases and suspected cases of influenza each epidemic season. WHO coordinates the international Global Influenza Surveillance Network consisting of international WHO reference centres for influenza in London, Atlanta, Tokyo, Melbourne and 115 national influenza centres in 86 countries all over the world. One of such National Influenza Centers is located in Poland at the National Institute of Hygiene in Warsaw Influenza surveillance provides information on the currently circulating strains of influenza viruses, including new variants and their spreading that allows to choose appropriate strains to include into the vaccine for the next epidemic season. Regional influenza surveillance networks also exist, as the European Influenza Surveillance Scheme (EISS). The epidemic season 2004/2005 was the first season when the integrated system of virological and epidemiological surveillance SENTINEL started to work in Poland, according to EISS indications. In this system there are included the selected family physicians representing the entire country, Voivodship Sanitary-Epidemiological Stations and the National Influenza Center. Data obtained by the SENTINEL system are then forwarded to EISS and WHO. Widely available way of prophylaxis against influenza is vaccination. Inactivated influenza vaccines prevent illness in 70%-90% healthy adults under 65 and in children. They also prevent post-influenza complications. Attenuated nasal influenza vaccines are registered to use in Russia and the United States. In Poland, vaccinations against influenza are considered in the Program of the Preventive Vaccinations as recommended since 1994. Vaccination against influenza is especially recommended for people who highly risk occurrence of post-influenza complications as well as for some groups of people due to epidemiological indications. Vaccine is administered before epidemic season, but it is also possible during the epidemic season when virus already circulates in the population. There are performed studies to improve currently vaccines, e.g. studies on the safe adjuvants (aluminium, MF59, virosoms), DNA vaccines, use of hemagglutinins and neuraminidase obtained by genetic recombination and expression in insect cells, studies on the production of influenza vaccines in the cell culture MDCK and Vero instead of currently used chicken embryos. There are available specific antiviral-antiinfluenza drugs of new generation: oseltamivir and zanamivir that are neuraminidase inhibitors and old generation drugs: amantadine and rimantadine that are inhibitors of M2 protein.

Humoral response to hemagglutinin components of influenza vaccine in patients with non-Hodgkin malignant lymphoma.

Lymphoma disease and immunosuppressive drugs used in this case cause immunity disorders increasing the risk of severe infections, including influenza. There are opinions that patients from high-risk group are not able to respond to vaccination effectively and vaccination may contribute to exacerbation of the chronic disease. The aim was to assess humoral response to influenza vaccine in 32 patients with non-Hodgkin malignant lymphoma (mean age 57.2) and 32 healthy subjects (mean age 44.3). Sixteen patients were treated with immunosupressive drugs (group A) and 11 were not subjected to this therapy (group B). Levels of antihemagglutinin (anti-HA) antibodies were assessed in sera before vaccination and after 1 month by hemagglutination inhibition test. Nasal and throat swabs were collected from persons with influenza symptoms during the study to detect the etiological agent of the infection. Post-vaccination anti-HA antibody levels were significantly higher than pre-vaccination values and mean fold increases (MFI) ranged from 9.3 to 12.2 in patients and from 27.6 to 44.3 in healthy subjects. The percentage of patients with the protective anti-HA antibody titers > or =1:40 (protection rate) ranged after vaccination from 59.4% to 68.8%. The percentage of patients with at least a four-fold increase of anti-HA antibody titers (response rate) after vaccination ranged from 46.9% to 68.8%. There were no significant differences in antibody levels between patients treated with immunosuppressive drugs and those not treated. No respiratory infections were laboratory confirmed. This study showed that influenza vaccine is less immunogenic in patients with non-Hodgkin malignant lymphoma, because it induces antibody production in lower titers in comparison to the production in healthy people. Despite this, influenza vaccine should be offered to this group, considering high MFI values and response rates as well as the protective effect for individual patients.

[Influenza diagnostics in patient with leukemia suspicion]. / Diagnostyka grypy u pacjenta z podejrzeniem bialaczki.

Influenza is a seasonal viral disease, with the peak of morbidity occurring in Poland between January and March. It is estimated that up to 70% of respiratory infections during the season is caused by this virus. Influenza virus infection poses an ultimate threat to the elderly > or = 65 years old and chronically ill, in whom postinfluenzal complications--including viral pneumonia and secondary bacterial pneumonia--cause from 0.1% to 0.4% deaths annually. Influenza also triggers off from 5% to 7% cases of nosocomial infections in these patients. Among three influenza types being human pathogens only influenza A and B have clinical and diagnostic significance. Type C causes mild respiratory infections, usually in children. Out of the viruses circulating in our region the most pathogenic is A/H3N2 subtype that causes more severe infections, an increased number of hospitalizations and higher mortality than A/ H1N1 or B viruses. Lack of pathognomonic symptoms makes difficult a case definition-based diagnosis and draws an attention to key role of laboratory diagnostics for respiratory infections. It has an essential significance in high-risk patients not vaccinated against influenza giving an opportunity to use antiviral drugs of the new generation as oseltamivir.

[Influenza in Poland in 2004]. / Grypa w 2004 roku.

A total number of 336,919 cases of influenza and influenza-like illness registered in Poland in 2004 (incidence 882.4 per 100 000 population). Regionally the incidence ranged from 226.2 per 100 000 population in Podlaskie to 2,122.3 in Mazowieckie. Children and adolescents under 15 years of age accounted for 30.5% of all cases (age specific incidence 1,588.2 per 100,000). In this age group the incidence varied regionally from 388,7 in Slaskie to 3,718.2 in Mazowieckie. 1,038 patients (0.31% of all cases) required hospital admission. There were 27 deaths due to influenza, in 85.2% these were persons over 70 years of age. In the epidemic season 2003/2004 six strains of influenza A/H3N2 virus were isolated in Poland. Antigenic analysis performed by the National Influenza Center showed that they were similar to strains A/Panama/2007/99 and A/Korea/770/02. Besides, in other 8 cases influenza A infection was confirmed by direct immunofluorescence test.

[Significance of virological diagnostics for the effective treatment of hospitalized patients infected with influenza virus]. / Znaczenie diagnostyki wirusologicznej dla skutecznosci leczenia hospitalizowanych chorych zakazonych wirusem grypy.

In the case of influenza disease there is no possible to make unquestionable diagnosis only on the basis of clinical picture. Therefore, virological laboratory diagnostics is important, especially in hospitalized patients and those who highly risk post-influenza complications and severe course of the disease. Virological diagnostic tests for influenza and positive result obtained in these tests allow to use effective antiviral-antiinfluenza drugs as new generation drugs: oseltamivir and zanamivir and also old generation drugs: amantadine and rimantadine. Since these antivirals are effective only in the case of influenza infection, diagnostic tests should be performed previously. Present methods allow to obtain the result of the test within less than 1 hour to 8 hours. This is of great importance, because the administration of the drug within 36 hours from the onset of symptoms is one of the factors conditioning the effectiveness of antiviral therapy. In the present paper there are described four cases of hospitalized patients in whom the infection with influenza virus was confirmed by immunofluorescence test and RT-PCR, and then the antiviral-antiinfluenza drugs were immediately introduced. This antiviral therapy in a short time resulted in the improvement of patients' condition and allowed to discharge them from the hospital. Antiviral-antiinfluenza drugs together with virological diagnostics are the effective tool in the case of patients not vaccinated against influenza, who were infected with influenza virus and fell ill.

[Influenza in Poland in 2003]. / Grypa w 2003 roku.

Following two years of low influenza incidence in Poland, the activity of this disease markedly increased in 2003. In total 1,216,285 cases of influenza like illness were registered (incidence 3,184.4 per 100,000). Regionally the incidence ranged from 1,195.7 in Zachodniopomorskie to 5,719.7 per 100,000 in Mazowieckie. Children and adolescents under 15 years of age accounted for 41.7% of all cases (507,102 cases, age specific incidence 7,579.0 per 100,000). In this age group the incidence varied regionally from 2,718.1 in Podlaskie to 14,087.6 per 100,000 in Mazowieckie. 3,128 patients (0.26% of all cases) required hospital admission. There were 141 deaths due to influenza (mortality 0.12%) in 2003, in 78.7% these were persons over 70 years of age. Nineteen strains of influenza virus were isolated in 2003 in Poland, including 15 strains of subtype A(H3), 3 strains of subtype A(H1) and one strain of type B. Besides, in other 10 cases influenza A infection was confirmed by direct immunofluorescence test. All isolated influenza strains were antigenically similar to the vaccine strains recommended for the epidemic season 2002/03 and 2003/04.

[Diagnostics of viral respiratory infections in hospitalized patients and ambulatory patients from SENTINEL program during 2004/05 season in Poland]. / Diagnostyka wirusowych infekcji oddechowych u pacjentów hospitalizowanych i pacjentów leczonych ambulatoryjnie objetych programem SENTINEL w sezonie 2004/05 w Polsce.

The aim of the study was to evaluate an impact of respiratory infections on the study population, type/subtype of influenza viruses circulating during 2004/05 season within the groups of hospitalised (n=35) and ambulatory patients (n=420) and to determine antigenic affinity of isolated viral strains. Laboratory diagnostics of influenza A and B type, RSV, adenovirus and parainfluenzavirus (type 1, 2 and 3) was performed using direct immunofluorescence test (DIFA), virus isolation on MDCK cell line and RT-PCR assay. Respiratory viruses were detected in about half of hospitalised patients and one fifth of ambulatory patients. Within these groups more than 80% hospitalised patients and 70% ambulatory patients were infected with influenza virus. Two influenza A subtypes (H3N2) and (H1N1) and B type were detected. Influenza ranged from 68,8% (26-45 age group) to 89,5% (15-25 age group) of all laboratory confirmed respiratory infections, only among the youngest children (0-3 years old) one fourth of infections was caused by influenza virus and in 50% samples RSV was detected. Influenza virus was also present in over 80% positive samples from hospitalised patients over 65 years old. Sensitivity of RT-PCR compared to other influenza diagnostic methods was 95% and specificity was > or = 99%. Fast and accurate influenza diagnostics using molecular biology methods enables implementing therapy with the new generation antivirals (neuraminidase inhibitors), that are effective only when administered up to 36-48 h from onset of the illness. In diagnostics of other. respiratory viruses it is necessary to apply more sensitive diagnostic methods e.g. multiplex RT-PCR. Influenza isolates were A/Wyoming/3/2003-like, B/Hong Kong/330/2001-like, A/New Caledonia/20/99-like and B/Jiangsu/10/2003-like strains that were components of influenza vaccines for 2003/04 and/or 2004/05 seasons. Annual vaccination remains the best way to prevent infection in high risk populations. Costs of influenza vaccine and oseltamivir prophylaxis in our country are on average respectively fifty and five times lower than each day of patients' stay at an intensiv care unit. Every year within the confines of global surveillance programs (e.g. SENTINEL), there are monitored circulating influenza viruses, in order to define vaccine composition for the next season and identify new and potentially pandemic strains.

[Influenza in Poland in 2002]. / Grypa w 2002 roku.

In 2002 the number of cases of influenza and influenza-like illness (ILI) registered in Poland amounted to 228,055. This is 39.5% of the number of cases recorded in 2001. The highest influenza incidence was found in Mazowieckie voivodship (2297.5 per 100,000), while the lowest incidence was registered in Swietokrzyskie voivodship (104.1) and Lubelskie voivodship (117.6). In children aged 0 to 14 years the number of influenza and ILI cases amounted to 104,552 (incidence of 1511.9 per 100,000) and this is 46% of the total number of cases recorded in 2002. The number of patients referred to hospitals amounted to 223, including 92 children aged 0-14 years. There were isolated 10 influenza strains, including 7 strains of subtype A (H3N2) and 3 strains of subtype A (H1N1). Immunofluorescence test carried out in 57 specimens did not confirm infection with influenza virus. Sero-surveys showed the lowest antihemagglutinin antibody levels in the age groups 0-3 and 4-7 years, while the highest in people aged 8-14 and 15-25 years.

Effect of influenza vaccinations on immune response and serum eotaxin level in patients with allergic bronchial asthma.

BACKGROUND: One of the most promising markers of allergic inflammation is eotaxin, which has a selective influence on the migration of eosinophils. Its serum content significantly correlates with the intensity of allergic symptoms, so it might be interesting to know whether vaccination has any influence on serum expression of this chemokine. AIMS: Comparison of the humoral response to influenza vaccine and post-vaccination changes in the serum eotaxin level in patients with allergic bronchial asthma and healthy controls. METHODS: Forty-two asthmatics and 45 healthy individuals were vaccinated with a single dose of influenza subunit vaccine (Influvac). The serum eotaxin level and the antibody response to haemagglutinin (HI) and neuraminidase (NI) glycoproteins were measured before and after vaccination. RESULTS: A significant increase of geometric mean titres of HI and NI was observed in both groups. There were no significant differences between the groups in meanfold increase of HI and NI titres, response rate and protective level of HI. After vaccination, a significant decrease of the mean serum eotaxin value was observed in patients with asthma (149.4 +/- 71.0 versus 125.1 +/- 67.0, p= 0.0017), while no similar effect was present in healthy individuals (153.4 +/- 56.9 versus 159.3 +/- 54.4, p= 0.5). CONCLUSIONS: The results indicate that in patients with allergic bronchial asthma influenza vaccinations assure efficient protective antibody level and modulate the serum level of eotaxin.

[Role of the European Scientific Work Group on Influenza in the battle against influenza]. / Rola Europejskiej Naukowej Grupy Roboczej ds. Grypy w walce z grypa.

The European Scientific Working group on Influenza (ESWI) was established in 1992. Its main task is to reduce impact of influenza in Europe by increase of awareness about influenza, dangers, methods of its prevention among physicians and in the society, stimulation of scientific studies, organizing of conferences, including those on the preparedness plans for the next pandemic. Infections, and in some cases also deaths, caused in humans by avian influenza viruses A(H5N1) in 1997 and 2003, A(H9N2) in 1999 and A(H7N7) in 2003 show that the outbreak of the next pandemic is a matter of time. Considering the above facts ESWI prepared a pilot study to introduce in Poland, Germany and Sweden. The main aim of this project is to achieve a better and more effective control of influenza by an increase of knowledge about influenza, promoting of vaccinations and new antiinfluenza drugs--neuraminidase inhibitors. In Poland project is coordinated by the National Influenza Center located at the National Institute of Hygiene, Warsaw. This is only one center in Poland and one of 112 similar centers in 83 countries of the world participating in the international program of influenza surveillance in cooperation with WHO, ESWI and European Influenza Surveillance Scheme.

Antibody response to influenza vaccination in splenectomized patients in Poland.

The aim of this study was to assess antibody response in 62 splenectomized patients and in 55 healthy subjects vaccinated with split influenza vaccine ("Fluarix," SmithKline Beecham). Response to hemagglutinin and neuraminidase was assessed before vaccination and after 1 month by hemagglutination inhibition test and neuraminidase inhibition test. After vaccination, antibody titers significantly increased in both groups. Postvaccination protection rates ranged from 62.9 to 90.3% in the splenectomized patients and from 81.8 to 94.5% in the control group. Response rates ranged from 50.0 to 75.8% and from 60.0 to 70.9%, respectively. Splenectomized patients produced high antibody levels regardless of the time elapsed from the operation to the vaccination. All requirements of the Committee for Proprietary Medicinal Products regarding humoral response to influenza vaccination in healthy people were fulfilled in both groups. The response in the splenectomized patients was comparable to that in the control group.

Immune consequences of the spontaneous pro-inflammatory status in depressed elderly patients.

INTRODUCTION: The aim of the study was to describe the interrelationship between senescence, depression, and immunity. METHODS: We assessed 10 elderly patients with depression and 10 age- and sex-matched controls: before, at one and at six month intervals after the anti-influenza vaccination. Levels of TNFalpha, IL6, ACTH, and cortisol, titres of anti-hemagglutinins and anti-neuraminidases, lymphocytes secreting IFNgamma, IL2, IL4, and IL10, cytotoxicity of NK and CD3+ CD8+ IFNgamma+ cells, anti-CMV antibodies, and CD28- CD57+ lymphocytes known to be associated with the CMV carrier status were evaluated. RESULTS: Higher levels of anti-CMV, higher percentage of the CD28- CD57+ cells, and elevated levels of TNFalpha, IL6, and cortisol concomitant with decreased levels of ACTH and insufficient production of IL10 (which increased the IFNgamma+ /IL10+ ratio) were found in the patients suffering from depression, in comparison to healthy controls. The subjects with depression revealed a low NK cytotoxicity, while a level of CD3+ CD8+ IFNgamma+ cells was comparable between the groups. Although the levels of anti-hemagglutinins and anti-neuraminidases were low in the depressed patients, they reached the protective titres. The majority of these differences disappeared when CMV titres were entered into the analyses as a covariate. DISCUSSION: The results suggest that the elderly depressed patients were characterised by increased exposure to CMV in the past, which could have resulted in a pro-inflammatory profile demonstrated as elevated levels of TNFalpha, IL6 and deficiency of suppressive IL10+ cells. These changes negatively affect humoral and innate response in the depressed patients.

[Influenza in Poland in 2001]. / Grypa w 2001 roku.

In 2001 the number of cases of influenza and influenza-like illness (ILI) registered in Poland amounted to 576,449. This is 36.1% of the number of cases recorded in 2000. The highest influenza incidence was found in Dolnoslaskie voivodship (3013.4 per 100,000), Mazowieckie voivodship (2688.5 per 100,000) and Zachodniopomorskie voivodship (2132.2 per 100,000). In children aged 0 to 14 years the number of influenza and ILI cases amounted to 275,358 (incidence was 3851.4 per 100,000) and this is 47.8% of the total number of cases recorded in 2001. The number of patients referred to hospitals amounted to 678 and 26 persons died. One influenza strain A(H1N1) was isolated from the patient aged 10. Immunofluorescence tests carried out in over 900 specimens did not confirm infection with influenza virus. Sero-surveys performed in the epidemic season 2001/2002 showed that the levels of antihemagglutinin antibodies were comparable for three antigens: A(H1N1), A(H3N2) and B. The highest antibody titers were recorded in the age group 15-25. Since May 2001 Poland is a member of the European Influenza Surveillance Scheme.

Association between cytomegalovirus infection, enhanced proinflammatory response and low level of anti-hemagglutinins during the anti-influenza vaccination--an impact of immunosenescence.

We assessed association between prior cytomegalovirus (CMV) infection, proinflammatory status and effectiveness of the anti-influenza vaccination. We examined 154 individuals during the epidemic season dividing them according to the age, response to the vaccine and the Senieur Protocol (SP). The anti-hemagglutinins (HI), tumour necrosis factor alpha (TNFalpha), interleukin (IL) 1beta, IL6, IL10, ACTH/cortisol axis, anti-CMV antibodies and CD28+CD57- lymphocytes were assessed. Non-responders of both ages we characterised by higher levels of anti-CMV IgG and higher percentages of CD57+CD28- lymphocytes (known to be associated with CMV carrier status) together with increased concentrations of TNFalpha and IL6 and decreased levels of cortisol. The anti-influenza vaccine induced increase in TNFalpha and IL10 in the all non-responders, while cortisol increased only in the young. Concluding, CMV carrier status eliciting elevated proinflammatory potential could contribute to unresponsiveness to the anti-influenza vaccine.

Immune response to influenza vaccination in an elderly population.

The purpose of this study was to assess the serum antibody responses to both the hemagglutinin and the neuraminidase antigens of inactivated influenza vaccine in 45 elderly and 28 younger adults. After vaccination, antihemagglutinin antibody levels increased significantly and mean fold increases ranged from 2.8 to 22.0. Seroprotection rates were between 42.2 and 91.1% 1 month after vaccination and 15.6 and 84.4% 5 months afterward. Seroresponse rates ranged from 42.2 to 91.1% 1 month after vaccination and 15.6 to 82.2% 5 months afterward. After vaccination antineuraminidase antibody levels increased significantly and mean fold increases ranged from 3.6 to 12.3. Significantly higher antibody responses to both hemagglutinin and neuraminidase were observed for antigen A(H3N2) than for antigens A(H1N1) and B. In most instances there were no statistically significant differences between the elderly and the control subjects. Influenza vaccine was immunogenic in the institutionalized elderly, who developed good antibody responses to influenza hemagglutinin and neuraminidase antigens.

[Influenza in Poland in 2000]. / Grypa w 2000 roku.

In 2000 the number of cases of influenza and influenza-like illness (ILI) registered in Poland amounted to 1,596,920 (68.1% of 1999 cases). The highest influenza incidence was reported in Lódzkie voivodship (9,388.8 cases per 100,000). Among children aged 0 to 14 years the number of influenza and ILI cases amounted to 408,495 (incidence 5,518.8 cases per 100,000) and was 25.5% of the total number of cases recorded in 2000. The number of patients referred to hospital was 7,028 and 358 persons died due to influenza and its complications. No influenza strains were isolated in 2000. Immunofluorescence test confirmed infection with influenza type A in 39 patients, while with type B--in 2 patients. Sero-surveys carried out in the epidemic season 2000/2001 showed that the highest antihemagglutinin antibody levels were produced for influenza strain A(H3N2) and B. The highest antibody titers were recorded in the age group 15-25, while the lowest levels--in the age group 0-3 years.

Efficacy of subunit trivalent influenza vaccine in previously vaccinated children suffering from hemophilia.

OBJECTIVE: To assess humoral immune response to subunit trivalent influenza vaccine in children suffering from hemophilia who had been immunized for the first time in 1993-94 and then in 1996-97. METHODS: In autumn 1996-97, 38 previously vaccinated hemophiliac patients were subcutaneously immunized with a single 0.5-mL dose of subunit influenza vaccine containing the following three virus strains: A/Singapore/6/86 (H1N1), A/Wuhan/359/95 (H3N2) and B/Beijing/184/93 (HB). Antibody response to influenza vaccine was measured before vaccination, 3 weeks after vaccination and 6 months after vaccination, by use of hemagglutinin- and neuraminidase-inhibition tests. To present the level of seroconversion, geometric mean titers of anti-influenza antibodies, mean fold increase, protection rate and conversion rate were determined. All results were compared with the control group of 23 healthy persons who had never been vaccinated against influenza and for whom the same serologic tests were carried out as for the vaccinated group. RESULTS: Three weeks after immunization, antihemagglutinin antibody levels were 3.9-10.9 times higher than before vaccination, but the highest mean fold increase values were recorded 6 months after vaccination, ranging from 8.4 to 28.6. In the case of neuraminidase, mean fold increases of antibodies reached values of 3.6-12.3 three weeks after vaccination and 7.1-29.1 six months after vaccination. The highest proportion of subjects protected was observed 6 months after immunization and ranged from 76.3% to 97.4%, compared to 52.6-60.5% 3 weeks after vaccination. Similar values were obtained for conversion rate: 71.1-86.8% 6 months after vaccination, in comparison with 39.5-42.1% 3 weeks after immunization. CONCLUSIONS: All data obtained in the present study indicate a significant immune response to subunit trivalent influenza vaccine in patients suffering from hemophilia; this is additionally confirmed by the fact that none of the vaccinated children were infected with the influenza virus and no serious adverse reactions were observed after administration of the vaccine.