E-rosette forming cells and humoral antibody titres in humans after vaccination with three different inactivated influenza virus vaccines A/USSR/92/77 (H1N1)

The number of E-rosette forming cells and the serum haemagglutination inhibition (HI) antibody titres were examined in 37 volunteers immediately before and 14, 28, 35 and 63 days after immunization with three inactivated influenza virus vaccines A/USSR/92/77 (H1N1)--NIB 6 and in 11 non-vaccinated controls. From the former, 10 volunteers were immunized with 1000 haemagglutinin (HA) IU per dose, 11 volunteers with the NIB 6 adsorbate vaccine (340 HA IU/dose) and 16 volunteers with a bivalent vaccine composed of 180 HA IU/dose NIB 6 and 180 HA IU/dose of influenza virus A/Bangkok X-73 (H3N2). The percentage of E-rosette forming cells was decreased in all vaccinated volunteers 14 days after vaccination; later on the values reached normal level of non-vaccinated controls or of subjects before vaccination. The number of E-rosette forming cells was in correlation with the applied virus vaccine dose, i.e. for the 1000 HA IU/dose: 29.95 +/- 11.74%, p less than 0.001 and for the 340 HA IU/dose: 47.75 +/- 11.15%, p less than 0.005; however, after administration of 180 HA IU/dose of NIB 6 in the bivalent vaccine, the value 58.65 +/- 11.5% was not significantly decreased in comparison to non-vaccinated donors. The serum HI antibody titres reached the highest level 14 days after vaccination and remained constant during the next 6 weeks. There was a correlation between decreased E-rosette values and increased serum antibody titres (p less than 0.05). The current study indicates that the number of E-rosette forming cells may serve as a further laboratory criterion for controlling the effect of inactivated influenza virus vaccines on the immune system of man.     

In Vivo Anti-Influenza Virus Activity of Kampo (Japanese Herbal) Medicine “Sho-Seiryu-To”—Effects on Aged Mice, Against Subtypes of a Viruses and B Virus, and Therapeutic Effect

When aged BALB/c mice (∼6 months old) were treated with a Kampo (Japanese herbal) medicine “Sho-seiryu-to (SST)” (1 g/kg, 10 times) orally from 7 days before to 4 days after the infection and infected with mouse-adapted influenza virus A/PR/8/34 (H1N1 subtype) by nasal site-restricted infection, replication of the virus in the broncho-alveolar cavity was efficiently inhibited at 5 days after infection in comparison with water-treated mice. The antiviral IgA antibody in the broncho-alveolar wash of the SST treated aged mice increased significantly. When mice (7 weeks old) were administered orally with SST (1 and 2 g/kg, 7 times) from 4 days before to 3 days after the infection and infected with mouse-adapted influenza virus A/Guizhou/54/89 (H3N2 subtype) or B/Ibaraki/2/85, replication of the viruses in the nasal cavity and lung were significantly inhibited at 4 days after infection in comparison with control mice. When mice infected with influenza virus A/Fukuoka/C29/85 (H3N2) before 14 days were secondary infected with A/PR/8 virus and administered orally with SST (1 g/kg, 5 times) from 2 h to 5 days after the secondary infection, replication of the virus in both nasal and broncho-alveolar cavities were significantly inhibited at 5 days after the secondary infection in comparison with water-treated control. Oral administration of SST (1 g/kg, 18 times) from 7 days before to 14 days after vaccination followed by secondary nasal inoculation of influenza HA vaccine (5 µglmouse) at 14 days after the first vaccination significantly augmented nasal antiviral IgA antibody and broncho-alveolar and serum antiviral IgG antibodies. These results suggest that SST is useful for influenza virus infection on aged persons and for cross-protection of subtypes of influenza A viruses and influenza B virus. SST is also useful for the treatment of influenza virus infection on human which has a history of influenza virus infection and/or influenza vaccination.     

甲型H1N1流行性感冒疫苗接种人群的血清抗体分析

目的:了解接种甲型H1N1流行性感冒(流感)疫苗后,人群中血清抗体的变化情况,为甲型H1N1流感疫苗的接种提供依据。方法:随机采集不同年龄已接种甲型H1N1流感疫苗人群的血清,采用血凝抑制实验检测血清中甲型H1N1流感抗体的血凝抑制滴度(HI滴度),HI滴度≥1∶40判定为阳性,同时调查采样对象的甲型H1N1流感疫苗与季节性流感疫苗的接种史。结果:甲型H1N1流感抗体阳性率为57.4%(402份/700份),抗体几何平均滴度(GMT)为1∶35.6;甲型H1N1流感抗体阳性率与GMT较高的是10～30岁组人群,较低的是60岁以上的人群;接种甲型H1N1流感疫苗后30～90天,GMT水平达到高峰(1∶56);随着季节性流感疫苗接种次数的增多,人群血清中甲型H1N1流感抗体的阳性率与GMT值反而降低。结论:青少年与成人接种甲型H1N1流感疫苗的免疫效果比儿童和老年人的好;甲型H1N1流感疫苗对人群的保护作用能持续90天左右;甲型H1N1流感抗体在0～10岁组,10～30岁组人群中持续的时间比30～60岁,>60岁组人群长;多次接种季节性流感疫苗可能会影响甲型H1N1流感抗体的产生。建议对儿童和老年人开展双倍剂量甲型H1N1流感疫苗接种;甲型H1N1流感疫苗的接种时间最好在流行期前1～3月内,并且应每年接种一次。     

Cell-mediated immune response of human lymphocytes to influenza A/USSR (H1N1) virus infection.

Cell-mediated immunity to influenza A/USSR (H1N1) virus was assessed by measuring transformation response and interferon production by Ficoll-Hypaque-purified peripheral blood lymphocytes from children and adults. Lymphocyte transformation was found to be related to the individual's previous experience with H1N1 influenza virus. Lymphocyte cultures, obtained from adults who had their last contact with the H1N1 virus over 20 years ago, were able to transform when incubated with H1N1 influenza antigens. This response suggests that influenza virus can induced long-term cell-mediated immunity for periods of at least 20 years. Interferon produced by stimulated lymphocytes was found to be unrelated to previous contact with influenza H1N1 virus; seronegative as well as seropositive individuals were capable of producing interferon in response to viral antigens. The interferon produced was type I.     

Functional immune response to influenza H1N1 in children and adults after live attenuated influenza virus vaccination

Influenza virus is a major respiratory pathogen, and vaccination is the main method of prophylaxis. In 2012, the trivalent live attenuated influenza vaccine (LAIV) was licensed in Europe for use in children. Vaccine‐induced antibodies directed against the main viral surface glycoproteins, haemagglutinin (HA) and neuraminidase (NA) play important roles in limiting virus infection. The objective of this study was to dissect the influenza‐specific antibody responses in children and adults, and T cell responses in children induced after LAIV immunization to the A/H1N1 virus. Blood samples were collected pre‐ and at 28 and 56 days post‐vaccination from 20 children and 20 adults. No increase in micro‐neutralization (MN) antibodies against A/H1N1 was observed after vaccination. A/H1N1 stalk‐specific neutralizing and NA‐inhibiting (NI) antibodies were boosted in children after LAIV. Interferon γ‐producing T cells increased significantly in children, and antibody‐dependent cellular‐mediated cytotoxic (ADCC) cell activity increased slightly in children after vaccination, although this change was not significant. The results indicate that the NI assay is more sensitive to qualitative changes in serum antibodies after LAIV. There was a considerable difference in the immune response in children and adults after vaccination, which may be related to priming and previous influenza history. Our findings warrant further studies for evaluating LAIV vaccination immunogenicity.     

Humans and Ferrets with Prior H1N1 Influenza Virus Infections Do Not Exhibit Evidence of Original Antigenic Sin after Infection or Vaccination with the 2009 Pandemic H1N1 Influenza Virus

The hypothesis of original antigenic sin (OAS) states that the imprint established by an individual''s first influenza virus infection governs the antibody response thereafter. Subsequent influenza virus infection results in an antibody response against the original infecting virus and an impaired immune response against the newer influenza virus. The purpose of our study was to seek evidence of OAS after infection or vaccination with the 2009 pandemic H1N1 (2009 pH1N1) virus in ferrets and humans previously infected with H1N1 viruses with various antigenic distances from the 2009 pH1N1 virus, including viruses from 1935 through 1999. In ferrets, seasonal H1N1 priming did not diminish the antibody response to infection or vaccination with the 2009 pH1N1 virus, nor did it diminish the T-cell response, indicating the absence of OAS in seasonal H1N1 virus-primed ferrets. Analysis of paired samples of human serum taken before and after vaccination with a monovalent inactivated 2009 pH1N1 vaccine showed a significantly greater-fold rise in the titer of antibody against the 2009 pH1N1 virus than against H1N1 viruses that circulated during the childhood of each subject. Thus, prior experience with H1N1 viruses did not result in an impairment of the antibody response against the 2009 pH1N1 vaccine. Our data from ferrets and humans suggest that prior exposure to H1N1 viruses did not impair the immune response against the 2009 pH1N1 virus.     

Influenza vaccination in HBsAg positive chronic active hepatitis patients treated with interferon

Sixteen patients with hepatitis B antigen (HBsAg) positive chronic active hepatitis (CAH) were vaccinated with the nonhuman influenza A virus Heq1Neq1; eight patients were also treated with leucocyte interferon. Prevaccination sera were negative for specific antibody in hemagglutination inhibition tests. Four weeks after vaccination all patients had responded with a homologous antibody titer. Between the interferon-treated and the untreated groups the differences in antibody titers against the vaccine virus were not significant. Concomitant with the antibody response against the nonhuman influenza virus, a fourfold or higher antibody rise was observed against the influenza A virus strains Hsw1N1 (in six treated and seven untreated patients), H1N1 (in six treated and four untreated patients) and H3N2 (in five treated patients only). The results suggest that a normal specific antibody response in HBsAg positive chronic active hepatitis patients is not significantly altered by leucocyte interferon, and that non-specific antibody production can occur in the absence of a serologic relationship.     

Influenza virus vaccination induces interleukin-12/23 receptor beta 1 (IL-12/23R beta 1)-independent production of gamma interferon (IFN-gamma) and humoral immunity in patients with genetic deficiencies in IL-12/23R beta 1 or IFN-gamma receptor I

To investigate whether protective immune responses can be induced in the absence of normal interleukin-12/23/gamma interferon (IL-12/23/IFN-gamma) axis signaling, we vaccinated with the seasonal influenza virus subunit vaccine two patients with complete IL-12/23 receptor beta1 (IL-12/23R beta 1) deficiencies, two patients with partial IFN-gamma receptor I (pIFN-gamma RI) deficiencies, and five healthy controls. Blood samples were analyzed before, 7 days after, and 28 days after vaccination. In most cases, antibody titers reached protective levels. Moreover, although T-cell responses in patients were lower than those observed in controls, significant influenza virus-specific T-cell proliferation, IFN-gamma production, and numbers of IFN-gamma-producing cells were found in all patients 7 days after the vaccination. Interestingly, influenza virus-specific IFN-gamma responses were IL-12/23 independent, in striking contrast to mycobacterium-induced IFN-gamma production. In conclusion, influenza virus vaccination induces IL-12/23-independent IFN-gamma production by T cells and can result in sufficient humoral protection in both IL-12/23R beta 1- and pIFN-gamma RI-deficient individuals.     

Mitogen responses and interferon production after exposure of human macrophages to infectious and inactivated influenza viruses

Human macrophages were exposed to two influenza A viruses representing different subtypes. The donors were likely to have been exposed to one subtype (H3N2) but not to the other (H0N 1). Similar effects upon the macrophages were observed for both subtypes: macrophage enhancement of mitogen-stimulated lymphocyte transformation responses was depressed, and the macrophages produced interferon. In contrast, macrophages exposed to inactivated virus exhibited normal enhancement of lymphocyte transformation response, yet produced interferon, although in lower titers than did macrophages exposed to infectious virus.     

Vaccination with cell immunoglobulin mucin-1 antibodies and inactivated influenza enhances vaccine-specific lymphocyte proliferation, interferon-gamma production and cross-strain reactivity

Influenza virus causes a contagious and potentially serious infection of the upper respiratory tract. While neutralizing antibodies are protective against infection, the problem of antigenic drift remains, requiring the constant monitoring and development of new vaccines. The magnitude of this situation is underscored by the emergence of new potentially human pathogenic influenza strains, avian H5N1 being the most recent example. We present evidence that antibodies against T cell immunoglobulin mucin-1 (TIM-1), a recently identified immunomodulatory molecule, stimulate cellular immunity against influenza viruses and cross-strain immune reactivity. To determine potential immunostimulatory properties of anti-TIM-1, mice were vaccinated with inactivated influenza virus in the presence or absence of TIM-1-specific monoclonal antibodies. Development of cellular immunity against both the influenza strain used for immunization and serotypically distinct virus strains was monitored 3 weeks after vaccination by determining antigen-specific lymphocyte proliferation and cytokine production. Results show that TIM-1 antibodies enhance antigen-specific cellular proliferation (P < 0.05) and interferon (IFN)-gamma production (P < 0.01). Using blocking anti-CD4 and CD8 antibodies, it was observed that antigen-specific cellular proliferation is CD4-dependent and that the majority of proliferating cells are CD4+. Finally, vaccination with inactivated influenza virus with TIM-1 antibody results in the significant (P < 0.001) induction of proliferation and IFN-gamma production upon stimulation with one of three serologically distinct strains. TIM-1 antibodies demonstrate an adjuvant effect promoting antigen-specific cellular proliferation and IFN-gamma production, which are important for the promotion of cell-mediated immunity. These results are the first to suggest that TIM-1 antibody may serve as a potent adjuvant in the development of new influenza virus vaccines.     

Lymphocyte blastogenic responses to influenza virus antigens after influenza infection and vaccination in humans.

Virus-specific in vitro cell-mediated immune responses were investigated in 20 normal volunteers who were challenged with liver influenza A/VIC/3/75 (H3N2) virus and in 13 volunteers who were vaccinated with inactivated vaccine containing A/VIC and A/NJ/8/76 (HswN1) antigens. Lymphocyte cultures were established from peripheral blood samples obtained prior to and at various times after infection or vaccination. Blastogenesis was determined by [3H]thymidine incorporation after stimulation of cultures with purified, inactivated, whole influenza viruses. Six days after infection, significantly elevated levels of blastogenesis were observed after in vitro stimulation with A viruses of hemagglutinin and neuraminidase subtypes that were the same as (H3N2) or antigenically distinct from (Heq1Neq1 or HswN1) those of the challenge virus, although maximum stimulation was noted with virus of the same hemagglutinin subtype (H3) as the challenge virus. Similar although more prolonged blastogenic responses were noted in lymphocyte cultures from vaccinees who had serum antibody rises after vaccination. The kinetics of these responses suggest that cell-mediated immunity may play a role in early events after infection and vaccination with influenza virus.     

Cell-mediated immune responses to the hemagglutinin and neuraminidase antigens of influenza A virus after immunization in humans.

Humoral and cell-mediated immunity (CMI) were evaluated in groups of school children after immunization with inactivated influenza virus vaccines. A conventional biphasic strain (H3ChN2Ch) of Port Chalmers influenza virus (X-41), a recombinant influenza virus specific for the neuraminidase antigen (Heq1N2Ch) of Port Chambers influenza A virus (X-42), and a placebo were employed for immunization. The techniques of hemagglutination inhibition and neuraminidase inhibition were used to determine serum antibody titers. The CMI responses were evaluated by the in vitro lymphocyte transformation assay employing HavN2Ch, Heq1Neq1, H3ChNeq1, and H3ChN2Ch influenza A virus strains as stimulants. Specific HAI antibody and CMI responses to H3Ch were observed in X-41 but not in X-42 vaccinees. Specific anti-neuraminidase antibodies and CMI responses to N2Ch were manifested by both X-41 and X-42 vaccinees. Immunization with the placebo resulted in no influenza-specific immune responses. The CMI response was first detectable 10 days after immunization and then declined. These observations demonstrate the induction of CMI responses to the HA and NA influenza surface antigens after immunization. These responses may be important in antiviral immunity and the recovery from influenza infection.     

Reduced antibody responses to the pandemic (H1N1) 2009 vaccine after recent seasonal influenza vaccination

The vaccination program against the 2009 pandemic H1N1 influenza virus (2009 H1N1) provided a unique opportunity to determine if immune responses to the 2009 H1N1 vaccine were affected by a recent, prior vaccination against seasonal influenza virus. In the present study, we studied the immune responses to the 2009 H1N1 vaccine in subjects who either received the seasonal influenza virus vaccination within the prior 3 months or did not. Following 2009 H1N1 vaccination, subjects previously given a seasonal influenza virus vaccination exhibited significantly lower antibody responses, as determined by hemagglutination inhibition assay, than subjects who had not received the seasonal influenza virus vaccination. This result is compatible with the phenomenon of "original antigenic sin," by which previous influenza virus vaccination hampers induction of immunity against a new variant. Our finding should be taken into account for future vaccination programs against pandemic influenza virus outbreaks.     

Characterization of the M2e antibody response following highly pathogenic H5N1 avian influenza virus infection and reliability of M2e ELISA for identifying infected among vaccinated chickens

A surveillance method able to differentiate between vaccinated and infected poultry is required for those countries that practice vaccination against highly pathogenic avian influenza H5N1. The external domain of the M2 protein (M2e) of influenza virus is a potentially useful differentiating-infected from vaccinated animals (DIVA) antigen but little is known about the M2e antibody response and factors influencing its detection. In this study, the M2e antibody response was characterized in layer birds vaccinated and challenged with an Indonesian H5N1 virus isolate, using a single M2e peptide or four-branched multiple antigenic peptide form of M2e (MAP-M2e) as antigens in two separate ELISAs. Anti-M2e antibodies were absent in chicks with high level of maternal haemagglutination inhibition antibodies and also in all layers vaccinated once, twice or three times with an inactivated commercial H5N1 vaccine. In contrast, anti-M2e antibodies were detected in vaccinated layers challenged with H5N1 virus and their presence was associated with virus isolation and an increase in haemagglutination inhibition titres. The number of birds that developed M2e antibodies, as well as the strength and duration of the M2e antibody response were strongly influenced by the length of the interval between vaccination and challenge. Birds challenged at six weeks after vaccination all developed M2e antibodies by 14 days that lasted until at least 56 days after infection. In birds challenged at two weeks after vaccination, only a proportion of birds developed M2e antibodies by 14 days that lasted only until 28 days post-infection. Both single M2e peptide and MAP-M2e ELISAs had high diagnostic specificity but the diagnostic sensitivity of MAP-M2e ELISA was significantly higher and more effective in detecting M2e antibody in immune and infected birds. The results show that MAP-M2e ELISA would be useful for surveillance in countries using vaccination to control highly pathogenic avian influenza H5N1.     

Field assessment of an H5N1 inactivated vaccine in chickens and ducks in Lao PDR

Despite the extensive use of poultry vaccines to control the spread of H5N1 influenza in poultry, H5N1 outbreaks continue to occur in domestic birds. Our objective was to determine the duration of the neutralizing antibody response under field conditions after vaccination with a laboratory-tested inactivated reverse genetics-derived H5N3 vaccine. H5N3 hemagglutination inhibition (HI) and virus neutralization (VN) antibodies were observed 40 weeks after vaccination of chickens with two doses and vaccination of ducks with one dose. Cross-clade antibodies to an H5N1 virus (A/chicken/Laos/A0464/07) antigenically distinct from the vaccine strain were detected in ducks after a single vaccination and were sustained for 28 weeks (for 40 weeks when a boost vaccination was given). Our results indicate that this inactivated H5N3 vaccine can produce long-lasting antibodies to homologous and heterologous viruses under field conditions.     

Responses to pandemic AS03-adjuvanted A/California/07/09 H1N1 influenza vaccine in human immunodeficiency virus-infected individuals

ABSTRACT: BACKGROUND: Influenza infection may be more serious in human immunodeficiency virus (HIV)-infected individuals, therefore, vaccination against seasonal and pandemic strains is highly advised. Seasonal influenza vaccines have had no significant negative effects in well controlled HIV infection, but the impact of adjuvanted pandemic A/California/07/2009 H1N1 influenza hemaglutinin (HA) vaccine, which was used for the first time in the Canadian population as an authorized vaccine in autumn 2009, has not been extensively studied. OBJECTIVE: Assess vaccine-related effects on CD4+ T cell counts and humoral responses to the vaccine in individuals attending the Newfoundland and Labrador Provincial HIV clinic. METHODS: A single dose of ArepanrixTM split vaccine including 3.75 mug A/California/07/2009 H1N1 HA antigen and ASO3 adjuvant was administered to 81 HIV-infected individuals by intramuscular injection. Plasma samples from shortly before, and 1--5 months after vaccination were collected from 80/81 individuals to assess humoral anti-H1N1 HA responses using a sensitive microbead-based array assay. Data on CD4+ T cell counts, plasma viral load, antiretroviral therapy and patient age were collected from clinical records of 81 individuals. RESULTS: Overall, 36/80 responded to vaccination either by seroconversion to H1N1 HA or with a clear increase in anti-H1N1 HA antibody levels. Approximately 1/3 (28/80) had pre-existing anti-H1N1 HA antibodies and were more likely to respond to vaccination (22/28). Responders had higher baseline CD4+ T cell counts and responders without pre-existing antibodies against H1N1 HA were younger than either non-responders or responders with pre-existing antibodies. Compared to changes in their CD4+ T cell counts observed over a similar time period one year later, vaccine recipients displayed a minor, transient fall in CD4+ T cell numbers, which was greater amongst responders. CONCLUSIONS: We observed low response rates to the 2009 pandemic influenza vaccine among HIV-infected individuals without pre-existing antibodies against H1N1 HA and a minor transient fall in CD4+ T cell numbers, which was accentuated in responders. A single injection of the ArepanrixTM pandemic A/California/07/2009 H1N1 HA split vaccine may be insufficient to induce protective immunity in HIV-infected individuals without pre-existing anti-H1N1 HA responses.     

遗传重配获得H5N1流感病毒Vero细胞适应株

目的以传统遗传重配技术选育HSN1流感病毒Veto细胞适应株,制备Vero细胞H5N1流感疫苗。方法以流感病毒Vero细胞适应株A／Yunnan／1／2005Va（H3N2）为母株与反向遗传学技术改造的禽流感病毒疫苗株A／Anhui／1／2005（H5N1）共同感染SPF鸡胚和Vero细胞,用羊抗A／Yunnan／1／2005Va（H3N2）抗体筛选,血抑试验和基因测序鉴定病毒型别,并进行重配株的其他相关生物学试验。结果获得了1株在Vero细胞高产的H5N1流感病毒,重配前后的单价灭活疫苗免疫小鼠抗体血清效价差异无统计学意义（F=0．857,P〉0．05）。结论通过流感病毒Vero细胞适应株与流行株的重配和抗体筛选,可以获得H5N1流感病毒Vero细胞适应株。     

Impact of preexisting memory to seasonal A/H1N1 influenza virus on the immune response following vaccination against avian A/H5N1 virus

Cross‐protection against divergent strains of influenza virus is an objective of various vaccination approaches. B cells cross‐neutralizing several influenza A heterosubtypes have been isolated from cultured human memory B cells (MBCs) and plasmablasts early after influenza vaccination or infection. However, a systematic assessment of the frequency of MBCs and plasmablasts in the blood of healthy individuals is lacking. Here, we show that under resting conditions about 45% of human adults never vaccinated nor exposed to avian A/H5N1 influenza have detectable circulating MBCs cross‐reacting with H5N1. This proportion rises to 63.3% among subjects with a large pool of MBCs specific for seasonal H1N1 (i.e. frequency ≥1% of total IgG MBCs). Moreover, subjects with high baseline frequencies of H1N1‐specific MBCs had an expansion of H5N1‐specific MBCs producing H5‐neutralizing antibodies already after the first dose of an MF59‐adjuvanted H5N1 vaccine. These results suggest that H1N1‐specific MBCs contain a subset of cells cross‐reacting to H5. We propose that a proportion of human adults have a pool of H5/H1 cross‐reactive MBCs that contribute to the rapid rise of the antibody response to divergent influenza strains. This may have implications on vaccination strategies aimed at counteracting future influenza pandemics.     

Virus-like particle vaccine containing hemagglutinin confers protection against 2009 H1N1 pandemic influenza

Immunization of the world population before an influenza pandemic such as the 2009 H1N1 virus spreads globally is not possible with current vaccine production platforms. New influenza vaccine technologies, such as virus-like-particles (VLPs), offer a promising alternative. Here, we tested the immunogenicity and protective efficacy of a VLP vaccine containing hemagglutinin (HA) and M1 from the 2009 pandemic H1N1 influenza virus (H1N1pdm) in ferrets and compared intramuscular (i.m.) and intranasal (i.n.) routes of immunization. Vaccination of ferrets with VLPs containing the M1 and HA proteins from A/California/04/2009 (H1N1pdm) induced high antibody titers and conferred significant protection against virus challenge. VLP-vaccinated animals lost less weight, shed less virus in nasal washes, and had markedly lower virus titers in all organs tested than naïve controls. A single dose of VLPs, either i.m. or i.n., induced higher levels of antibody than did two doses of commercial split vaccine. Ferrets vaccinated with split vaccine were incompletely protected against challenge; these animals had lower virus titers in olfactory bulbs, tonsils, and intestines, but lost weight and shed virus in nasal washes to a similar extent as naïve controls. Challenge with heterologous A/Brisbane/59/07 (H1N1) virus revealed that the VLPs conferred minimal cross-protection to heterologous infection, as revealed by the lack of reduction in nasal wash and lung virus titers and slightly higher weight loss relative to controls. In summary, these experiments demonstrate the strong immunogenicity and protective efficacy of VLPs compared to the split vaccine and show that i.n. vaccination with VLPs has the potential for highly efficacious vaccination against influenza.     

In Vivo Anti-Influenza Virus Activity of Kampo (Japanese Herbal) Medicine “Sho-Seiryu-To”—Stimulation of Mucosal Immune System and Effect on Allergic Pulmonary Inflammation Model Mice

When BALB/c mice were treated with a Kampo (Japanese herbal) medicine “Sho-seiryu-to (SST)” (1 g/kg, 10 times) orally from 7 days before to 5 days after the infection and infected with mouse-adapted influenza virus A/PR/8/34 by nasal-site restricted infection, SST caused increment of the influenza virus hemagglutinin-specific IgA antibody secreting cells in nasal lymphocyte but not in Peyer's patch lymphocyte at 6 days after infection in comparison with water-treated mice. Oral administration of SST also augmented IL-2 receptor β chain⁺ (activated) T-cell in Peyer's patch lymphocyte, but not in the nasal lymphocyte. We previously reported that SST showed potent anti-influenza virus activity through augmentation of the antiviral IgA antibody titer in the nasal and broncho-alveolar cavities of the mice (T. Nagai and H. Yamada, 1994, Int. J. Immunopharmacol. 16, 605-613). These results suggest that oral administration of SST shows anti-influenza virus activity in the nasal cavity by activatation of T-cell in Peyer's patch lymphocyte and stimulation of production of anti-influenza virus IgA antibody in nasal lymphocyte. When ovalbumin-sensitized allergic pulmonary inflammation model mice were administered orally with SST (1 g/kg) from 8 days before (11 times) or from 2 h after (4 times) to 4 days after the infection and infected with mouse-adapted influenza virus A/PR/8/34, replications of the virus in the both nasal and broncho-alveolar cavities or only nasal cavity were significantly inhibited at 5 days after infection in comparison with water-treated control by augmenting antiviral IgA antibody, respectively. These results suggest that SST is useful for both prophylaxis and treatment of influenza virus infection on patients with allergic pulmonary inflammation, such as bronchial asthma.