Immunity against influenza A(H1N1) infections is determined by age at the time of initial strain circulation

SUMMARYWe explored age-dependent patterns in haemagglutination inhibition (HI) titre to seasonal [1956 A(H1N1), 1977 A(H1N1), 2007 A(H1N1)] and pandemic [A(H1N1)pdm09] influenza strains using serological data collected from an adult French influenza cohort. Subjects were recruited by their general practitioners from 2008 to 2009 and followed until 2010. We explored age-related differences between strain-specific HI titres using 1053 serological samples collected over the study period from 398 unvaccinated subjects. HI titres against the tested seasonal and pandemic strains were determined using the HI technique. Geometric mean titres (GMTs) were estimated using regression models for interval-censored data. Generalized additive mixed models were fit to log-transformed HI estimates to study the relationship between HI titre and age (age at inclusion and/or age at initial strain circulation). GMT against one strain was consistently highest in the birth cohort exposed to that strain during childhood, with peak titres observed in subjects aged 7–8 years at the time of initial strain circulation. Our results complete previous findings on influenza A(H3N2) strains and identify a strain-dependent relationship between HI titre and age at initial strain circulation.

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Immune response to influenza A(H1N1)v in HIV-infected patients

The Journal of Infection in Developing Countries ◽

10.3855/jidc.3147 ◽

2014 ◽

Vol 8 (01) ◽

pp. 101-109 ◽

Cited By ~ 4

Author(s):

Paola Sansonetti ◽

Michela Sali ◽

Massimiliano Fabbiani ◽

Matteo Morandi ◽

Rosa Martucci ◽

...

Keyword(s):

Immune Response ◽

Hiv Infection ◽

Clinical Picture ◽

Influenza A ◽

Geometric Mean ◽

Haemagglutination Inhibition ◽

Hiv Positive ◽

Upper Respiratory Tract ◽

Influenza A H1n1 ◽

Hiv Negative

Introduction: HIV infection is considered a risk factor for severe outcomes of influenza A(H1N1)v infection. However, data on immune response against influenza A(H1N1)v virus in HIV-infected patients are lacking. Methodology: Data from seven HIV-positive and 14 HIV-negative patients infected with A(H1N1)v and from 23 HIV-positive and six HIV-negative asymptomatic controls were analyzed to evaluate the clinical picture, A(H1N1)v viral shedding, and the immune response against the virus. Results: Patients displayed mainly upper respiratory tract diseases (57.1%), while pneumonia was diagnosed only in HIV-negative patients (23.8% of subjects, of which 4.8% required intensive care unit admission). At day seven, 29% of HIV-infected patients were still positive for A(H1N1)v by RT-PCR on nasopharyngeal swabs. Interestingly, a persistence of CXCL10 secretion at high level and lower IL-6 levels was observed in HIV-positive subjects. The geometric mean haemagglutination inhibition titer (HI-GMT) and anti-influenza IgM levels were lower in HIV-positive individuals while anti-influenza IgG levels remained similar in the two groups. Conclusions: The immune impairment due to HIV infection could affect A(H1N1)v clearance and could lead to a lower antibody response and a persistent secretion of CXCL10 at high levels. However, the lower IL-6 secretion and treatment with highly active antiretroviral therapy (HAART) could result in a milder clinical picture.

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Influenza A (H1N1) virus infection and TNF-308, IL6, and IL8 polymorphisms in Egyptian population: a case–control study

The Journal of Basic and Applied Zoology ◽

10.1186/s41936-019-0131-1 ◽

2019 ◽

Vol 80 (1) ◽

Cited By ~ 1

Author(s):

Shaimaa Moustafa Elsayed ◽

Omayma Mohamed Hassanein ◽

Nagwa Hassan Ali Hassan

Keyword(s):

Influenza A ◽

Case Control Study ◽

H1n1 Virus ◽

Case Control ◽

Severe Illness ◽

Study Results ◽

Influenza A H1n1 ◽

Pandemic Strains ◽

Study Participants ◽

Control Study

Abstract Background The importance of influenza is increasing mainly because of the appearance of novel pandemic strains such as swine and avian. Each year, influenza has spread around the world causing about 250,000–500,000 deaths and more than 5 million cases of severe illness. The objective is as follows: evaluating the outcomes of patients with influenza A (H1N1) virus in relation to certain TNF-308, IL6, and IL8 polymorphisms and identifying the associated factors with the severe outcome. Subject and methods This is a case–control study. The cases were patients confirmed by real-time polymerase chain reaction (RT-PCR) to be influenza A (H1N1) virus infected. The controls were healthy individuals. Medical history and outcome of the disease was registered. In all study participants, polymorphisms of TNF rs1800629, IL6 rs18138879, and IL8 rs4073; odds ratio (OR); and the 95% confidence interval (95% CI) were calculated. Results Infection with influenza A (H1N1) virus was associated more with the following genotypes: TNF-308 AA (OR = 4.041; 95% CI = 1.215–13.4) and IL8 AA (OR = 3.273; 95% CI = 1.372–7.805). According to our study results, HCV (OR = 3.2, 95% CI 1.2–8.5), renal disease (OR = 3.4, 95% CI 0.9–13.6), cancer (OR = 3.1, 95% CI 0.3–31.1), TB (OR = 8.4, 95% CI 1.8–39.7), ICU (OR = 2.9, 95%1.2–7.1), and mortality (OR = 7.9, 95% CI 0.9–67.4) are considered as risk factors for influenza A (H1N1)-infected patients. Conclusions Our findings concluded that TNF-308 (AA) and IL8 (AA) polymorphisms may increase the susceptibility to be infected with H1N1influenza virus.

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The importance of antineuraminidase antibodies in resistance to influenza A and immunologic memory for their synthesis

Journal of Hygiene ◽

10.1017/s0022172400060101 ◽

1983 ◽

Vol 91 (1) ◽

pp. 131-138 ◽

Cited By ~ 6

Author(s):

A. N. Naikhin ◽

I. M. Tsaritsina ◽

E. V. Oleinikova ◽

L. G. Syrodoeva ◽

N. L. Korchanova ◽

...

Keyword(s):

Protective Effect ◽

Influenza A ◽

Natural Infection ◽

Haemagglutination Inhibition ◽

Surface Antigens ◽

Antigenic Structure ◽

Immunologic Memory ◽

Antibody Synthesis ◽

Influenza A H1n1 ◽

Simplified Method

SUMMARYEight hundred and seventy-seven sera from 360 adults aged 18–50 who were under permanent observation from October 1980 to March 1981 have been studied by haemagglutination-inhibition (HI) and erythrocyte elution-inhibition (EI) tests – a simplified method of antineuraminidase antibody titration. It was demonstrated in some subjects infected with influenza A H1N1 and H3N2 viruses that the antibody rise was to one of the surface antigens only – haemagglutinin or neuraminidase. These subjects made up 5·2–25·8% of all examinees. The protective effect of antibodies to neuraminidase was similar to that of antihaemagglutinins. Interaction of both types of antibodies was observed in protection against the disease. Data have been obtained on the influence of antineuraminidase antibodies in decreasing the severity of natural infection with influenza A.A study of heterologous immunologic responses to haemagglutinin and neuraminidase among persons immunized with live influenza A H1N1 and H3N2 vaccines and among children naturally infected with influenza A H3N2 demonstrated the presence of immunologic memory for antineuraminidase antibody synthesis. Thus, the suggestion of a common antigenic structure for neuraminidase Nl and N2 is made.

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Immunogenicity of a Monovalent Pandemic Influenza A H1N1 Virus Vaccine with or without Prior Seasonal Influenza Vaccine Administration

Clinical and Vaccine Immunology ◽

10.1128/cvi.00077-12 ◽

2012 ◽

Vol 19 (10) ◽

pp. 1690-1692 ◽

Cited By ~ 1

Author(s):

Hidetoshi Igari ◽

Akira Watanabe ◽

Shunsuke Segawa ◽

Akiko Suzuki ◽

Mariko Watanabe ◽

...

Keyword(s):

Influenza Vaccine ◽

Pandemic Influenza ◽

Influenza A ◽

H1n1 Virus ◽

Geometric Mean ◽

Vaccine Administration ◽

Trivalent Influenza Vaccine ◽

Influenza A H1n1 ◽

Significant Difference ◽

Antibody Titers

ABSTRACTThe immunogenicity of pandemic influenza A H1N1 virus (A/H1pdm) vaccine might be modified by prior seasonal trivalent influenza vaccine (sTIV) administration. We conducted a retrospective analysis of immunogenicity of 243 health care workers (number of sTIV-positive [sTIV+] subjects, 216; number of sTIV−subjects, 27) by hemagglutination inhibition. There was no significant difference in the ratios of antibody titers of ≥40 (41.2% versus 48.1%;P= 0.49) and fold increases in geometric mean titer (3.8 versus 4.5;P= 0.37). sTIV injected 7 to 10 days prior to A/H1pdm vaccine administration did not interfere with the immunogenicity of the latter.

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Immune Activation and Viral Replication after Vaccination with an Influenza A H1N1 2009 Vaccine in HIV-Infected Children Receiving Antiretroviral Therapy

Disease Markers ◽

10.1155/2013/276547 ◽

2013 ◽

Vol 35 ◽

pp. 221-227 ◽

Cited By ~ 1

Author(s):

Nattawat Onlamoon ◽

Petai Unpol ◽

Michittra Boonchan ◽

Kasama Sukapirom ◽

Orasri Wittawatmongkol ◽

...

Keyword(s):

T Cells ◽

Antiretroviral Therapy ◽

Viral Replication ◽

Cd8 T Cells ◽

Immune Activation ◽

Influenza A ◽

Haemagglutination Inhibition ◽

Hla Dr ◽

Influenza A H1n1 ◽

The Impact

Immunization with a pandemic influenza A H1N1 2009 was recommended for HIV-infected patients. However, there is limited information concerning the impact of immunization with this vaccine on immune activation and HIV viral replication. In this study, 45 HIV-infected children and adolescents receiving antiretroviral therapy were immunized with a 2-dose series of nonadjuvated monovalent influenza A H1N1 2009 vaccine upon enrollment and approximately 1 month later. Immunogenicity was determined by haemagglutination inhibition assay. The level of immune activation was determined by identification of CD38 and HLA-DR on CD8+ T cells. Patients were divided into 2 groups which include patients who had an undetectable HIV viral load (HIV detectable group) and patients who show virological failure (HIV nondetectable group). The results showed seroconversion rate of 55.2% in HIV nondetectable group, whereas 31.3% was found in HIV detectable group. Both groups of patients showed no major increase in immune activation after immunization. Interestingly, a decrease in the frequency of CD8+ T cells that coexpressed CD38 and HLA-DR was observed after immunization in both groups of patients. We suggested that immunization with influenza A H1N1 2009 vaccine can induce immune response to the pandemic virus without major impact on HIV viral replication and immune activation.

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Glucocorticoid: Major Factor for Reduced Immunogenicity of 2009 Influenza A (H1N1) Vaccine in Patients with Juvenile Autoimmune Rheumatic Disease

The Journal of Rheumatology ◽

10.3899/jrheum.110721 ◽

2011 ◽

Vol 39 (1) ◽

pp. 167-173 ◽

Cited By ~ 39

Author(s):

NADIA E. AIKAWA ◽

LUCIA M.A. CAMPOS ◽

CLOVIS A. SILVA ◽

JOZELIO F. CARVALHO ◽

CARLA G.S. SAAD ◽

...

Keyword(s):

Rheumatic Disease ◽

Influenza A ◽

Seroconversion Rate ◽

Geometric Mean ◽

Healthy Controls ◽

Seroprotection Rate ◽

H1n1 Vaccine ◽

Link Type ◽

Autoimmune Rheumatic Disease ◽

Influenza A H1n1

Objective.To assess the immunogenicity and safety of non-adjuvanted influenza A H1N1/2009 vaccine in patients with juvenile autoimmune rheumatic disease (ARD) and healthy controls, because data are limited to the adult rheumatologic population.Methods.A total of 237 patients with juvenile ARD [juvenile systemic lupus erythematosus (JSLE), juvenile idiopathic arthritis (JIA), juvenile dermatomyositis (JDM), juvenile scleroderma, and vasculitis] and 91 healthy controls were vaccinated. Serology for anti-H1N1 was performed by hemagglutination inhibition assay. Seroprotection rate, seroconversion rate, and factor-increase in geometric mean titer (GMT) were calculated. Adverse events were evaluated.Results.Age was comparable in patients and controls (14.8 ± 3.0 vs 14.6 ± 3.7 years, respectively; p = 0.47). Three weeks after immunization, seroprotection rate (81.4% vs 95.6%; p = 0.0007), seroconversion rate (74.3 vs 95.6%; p < 0.0001), and the factor-increase in GMT (12.9 vs 20.3; p = 0.012) were significantly lower in patients with juvenile ARD versus controls. Subgroup analysis revealed reduced seroconversion rates in JSLE (p < 0.0001), JIA (p = 0.008), JDM (p = 0.025), and vasculitis (p = 0.017). Seroprotection (p < 0.0001) and GMT (p < 0.0001) were decreased only in JSLE. Glucocorticoid use and lymphopenia were associated with lower seroconversion rates (60.4 vs 82.9%; p = 0.0001; and 55.6 vs 77.2%; p = 0.012). Multivariate logistic regression including diseases, lymphopenia, glucocorticoid, and immunosuppressants demonstrated that only glucocorticoid use (p = 0.012) remained significant.Conclusion.This is the largest study to demonstrate a reduced but adequate immune response to H1N1 vaccine in patients with juvenile ARD. It identified current glucocorticoid use as the major factor for decreased antibody production. The short-term safety results support its routine recommendation for patients with juvenile ARD. ClinicalTrials.gov; NCT01151644.

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Molecular detection of influenza A(H1N1)pdm09 viruses with M genes from human pandemic strains among Nigerian pigs, 2013–2015: implications and associated risk factors

Epidemiology and Infection ◽

10.1017/s0950268817002503 ◽

2017 ◽

Vol 145 (16) ◽

pp. 3345-3360 ◽

Cited By ~ 5

Author(s):

O. A. ADEOLA ◽

B. O. OLUGASA ◽

B. O. EMIKPE

Keyword(s):

Risk Factors ◽

Influenza A ◽

Influenza Viruses ◽

Scan Statistics ◽

Rt Pcr ◽

Pandemic Virus ◽

Influenza A H1n1 ◽

Pandemic Strains ◽

Associated Risk Factors ◽

Ibadan Nigeria

SUMMARYIn the post-pandemic period, influenza A(H1N1)pdm09 virus has been detected in swine populations in different parts of the world. This study was conducted to determine the presence and spatial patterns of this human pandemic virus among Nigerian pigs and identify associated risk factors. Using a two-stage stratified random sampling method, nasal swab specimens were obtained from pigs in Ibadan, Nigeria during the 2013–2014 and 2014–2015 influenza seasons, and the virus was detected by reverse transcriptase-polymerase chain reaction (RT-PCR). Purified RT-PCR products were sequenced in both directions, and sequences were aligned using MUSCLE. Phylogenetic analysis was conducted in MEGA6. Purely spatial scan statistics and a spatial lag regression model were used to identify spatial clusters and associated risk factors. The virus was detected in both seasons, with an overall prevalence of 8·7%. Phylogenetic analyses revealed that the M genes were similar to those of pandemic strains which circulated in humans prior to and during the study. Cluster analysis revealed a significant primary spatial cluster (RR = 4·71, LLR = 5·66,P= 0·0046), while ‘hours spent with pigs (R2= 0·90,P= 0·0018)’ and ‘hours spent with pigs from different farms (R2= 0·91,P= 0·0001)’ were identified as significant risk factors (P< 0·05). These findings reveal that there is considerable risk of transmission of the pandemic virus, either directly from pig handlers or through fomites, to swine herds in Ibadan, Nigeria. Active circulation of the virus among Nigerian pigs could enhance its reassortment with endemic swine influenza viruses. Campaigns for adoption of biosecurity measures in West African piggeries and abattoirs should be introduced and sustained in order to prevent the emergence of a new influenza epicentre in the sub-region.

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Sex- and Age-Related Differences in Morbidity Rates of 2009 Pandemic Influenza A H1N1 Virus of Swine Origin in Japan

PLoS ONE ◽

10.1371/journal.pone.0019409 ◽

2011 ◽

Vol 6 (4) ◽

pp. e19409 ◽

Cited By ~ 30

Author(s):

Nobuoki Eshima ◽

Osamu Tokumaru ◽

Shohei Hara ◽

Kira Bacal ◽

Seigo Korematsu ◽

...

Keyword(s):

Pandemic Influenza ◽

Influenza A ◽

H1n1 Virus ◽

Age Related ◽

Influenza A H1n1

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Age, influenza pandemics and disease dynamics

Epidemiology and Infection ◽

10.1017/s0950268810000579 ◽

2010 ◽

Vol 138 (11) ◽

pp. 1542-1549 ◽

Cited By ~ 20

Author(s):

A. L. GREER ◽

A. TUITE ◽

D. N. FISMAN

Keyword(s):

Influenza A ◽

H1n1 Virus ◽

Influenza Pandemic ◽

Reproductive Number ◽

Disease Dynamics ◽

Older Individuals ◽

Related Factors ◽

Age Related ◽

Influenza A H1n1 ◽

Dynamics And Control

SUMMARYThe world is currently confronting the first influenza pandemic of the 21st century [caused by a novel pandemic influenza A (H1N1) virus]. Earlier pandemics have been characterized by age distributions that are distinct from those observed with seasonal influenza epidemics, with higher attack rates (and correspondingly increased proportionate or relative mortality) in younger individuals. While the genesis of protection against infection in older individuals during a pandemic is uncertain, differential vulnerability to infection by age has important implications for disease dynamics and control, and for choice of optimal vaccination strategies. Age-related vulnerability to infection may explain differences between school- and community-derived estimates of the reproductive number (R) for a newly emerged pandemic strain, and may also help explain the failure of a newly emerged influenza A (H1N1) virus strain to cause a pandemic in 1977. Age-related factors may also help explain variability in attack rates, and the size and impact of influenza epidemics across jurisdictions and between populations. In Canada, such effects have been observed in the apparently increased severity of outbreaks on Indigenous peoples' reserves. The implications of these patterns for vaccine allocation necessitate targeted research to understand age-related vulnerabilities early in an influenza pandemic.

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Immunogenicity and safety of the 2009 non-adjuvanted influenza A/H1N1 vaccine in a large cohort of autoimmune rheumatic diseases

Annals of the Rheumatic Diseases ◽

10.1136/ard.2011.150250 ◽

2011 ◽

Vol 70 (6) ◽

pp. 1068-1073 ◽

Cited By ~ 57

Author(s):

Carla G S Saad ◽

Eduardo F Borba ◽

Nadia E Aikawa ◽

Clovis A Silva ◽

Rosa M R Pereira ◽

...

Keyword(s):

Lupus Erythematosus ◽

Influenza A ◽

Geometric Mean ◽

Vaccine Safety ◽

Primary Antiphospholipid Syndrome ◽

H1n1 Vaccine ◽

Link Type ◽

Autoimmune Rheumatic Disease ◽

Influenza A H1n1 ◽

2009 H1n1

BackgroundDespite the WHO recommendation that the 2010–2011 trivalent seasonal flu vaccine must contain A/California/7/2009/H1N1-like virus there is no consistent data regarding its immunogenicity and safety in a large autoimmune rheumatic disease (ARD) population.Methods1668 ARD patients (systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), ankylosing spondylitis (AS), systemic sclerosis, psoriatic arthritis (PsA), Behçet's disease (BD), mixed connective tissue disease, primary antiphospholipid syndrome (PAPS), dermatomyositis (DM), primary Sjögren's syndrome, Takayasu's arteritis, polymyositis and Granulomatosis with polyangiitis (Wegener's) (GPA)) and 234 healthy controls were vaccinated with a non-adjuvanted influenza A/California/7/2009(H1N1) virus-like strain flu. Subjects were evaluated before vaccination and 21 days post-vaccination. The percentage of seroprotection, seroconversion and the factor increase in geometric mean titre (GMT) were calculated.ResultsAfter immunisation, seroprotection rates (68.5% vs 82.9% p<0.0001), seroconversion rates (63.4% vs 76.9%, p<0.001) and the factor increase in GMT (8.9 vs 13.2 p<0.0001) were significantly lower in ARD than controls. Analysis of specific diseases revealed that seroprotection significantly reduced in SLE (p<0.0001), RA (p<0.0001), PsA (p=0.0006), AS (p=0.04), BD (p=0.04) and DM (p=0.04) patients than controls. The seroconversion rates in SLE (p<0.0001), RA (p<0.0001) and PsA (p=0.0006) patients and the increase in GMTs in SLE (p<0.0001), RA (p<0.0001) and PsA (p<0.0001) patients were also reduced compared with controls. Moderate and severe side effects were not reported.ConclusionsThe novel recognition of a diverse vaccine immunogenicity profile in distinct ARDs supports the notion that a booster dose may be recommended for diseases with suboptimal immune responses. This large study also settles the issue of vaccine safety.(ClinicalTrials.gov #NCT01151644)

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