scholarly journals Comparison of Serum Hemagglutinin and Neuraminidase Inhibition Antibodies After 2010–2011 Trivalent Inactivated Influenza Vaccination in Healthcare Personnel

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Maryrose R. Laguio-Vila ◽  
Mark G. Thompson ◽  
Sue Reynolds ◽  
Sarah M. Spencer ◽  
Manjusha Gaglani ◽  
...  
Keyword(s):  
Influenza Vaccine ◽  
Influenza A ◽  
Influenza Infection ◽  
Fold Increase ◽  
Healthcare Personnel ◽  
Virus Infections ◽  
Influenza A Viruses ◽  
Duration Of Illness ◽  
Antibody Titers ◽  
Influenza Vaccinations

Abstract Background.  Most inactivated influenza vaccines contain purified and standardized hemagglutinin (HA) and residual neuraminidase (NA) antigens. Vaccine-associated HA antibody responses (hemagglutination inhibition [HAI]) are well described, but less is known about the immune response to the NA. Methods.  Serum of 1349 healthcare personnel (HCP) electing or declining the 2010–2011 trivalent-inactivated influenza vaccine ([IIV3], containing A/California/7/2009 p(H1N1), A/Perth/16/2009 [H3N2], B/Brisbane/60/2008 strains) were tested for NA-inhibiting (NAI) antibody by a modified lectin-based assay using pseudotyped N1 and N2 influenza A viruses with an irrelevant (H5) HA. Neuraminidase-inhibiting and HAI antibody titers were evaluated approximately 30 days after vaccination and end-of-season for those with polymerase chain reaction (PCR)-confirmed influenza infection. Results.  In 916 HCP (68%) receiving IIV3, a 2-fold increase in N1 and N2 NAI antibody occurred in 63.7% and 47.3%, respectively. Smaller responses occurred in HCP age >50 years and those without prior 2009–2010 IIV3 nor monovalent A(H1N1)pdm09 influenza vaccinations. Forty-four PCR-confirmed influenza infections were observed, primarily affecting those with lower pre-exposure HAI and NAI antibodies. Higher pre-NAI titers correlated with shorter duration of illness for A(H1N1)pdm09 virus infections. Conclusions.  Trivalent-inactivated influenza vaccine is modestly immunogenic for N1 and N2 antigens in HCP. Vaccines eliciting robust NA immune responses may improve efficacy and reduce influenza-associated morbidity.

scholarly journals Age-specific differences in the dynamics of protective immunity to influenza

2018 ◽  
Author(s):  
Sylvia Ranjeva ◽  
Rahul Subramanian ◽  
Vicky J. Fang ◽  
Gabriel M. Leung ◽  
Dennis K. M. Ip ◽  
...  
Keyword(s):  
Protective Immunity ◽  
Influenza A ◽  
Influenza Infection ◽  
Age Groups ◽  
Virus Infections ◽  
Influenza A Viruses ◽  
Individual Level ◽  
Antibody Titers ◽  
Original Antigenic Sin ◽  
Changes Over Time

AbstractInfluenza A viruses evolve rapidly to escape host immunity, such that individuals can be infected multiple times with the same subtype. The form and duration of protective immunity after each influenza infection are poorly understood. Here, we quantify the dynamics of protective immunity against influenza A virus infections by fitting individual-level mechanistic models to longitudinal serology from children and adults in a household cohort study. We find that most protection in children is explained by antibody titers measured by the hemagglutination inhibition (HI) assay. In contrast, in adults, HI antibody titers explain a smaller fraction of protection. Protection against circulating strains wanes to approximately 50% of peak levels 3.5-7 years after infection in both age groups, and wanes faster against influenza A(H3N2) than A(H1N1)pdm09. Protection against H3N2 lasts longer in adults than in children. Our results suggest that the focus of influenza antibody responses changes over time from the highly mutable hemagglutinin head to other epitopes, consistent with the immunological theory of original antigenic sin, and that this change of focus might affect protection. Additionally, we estimate that imprinting, or primary infection with a subtype of one phylogenetic group, has little to no effect on the risk of non-medically attended influenza infections in adults. We also find no evidence of long-term cross-protection between subtypes. This work underscores the need for longitudinal data on multiple components of the immune response to better understand the development of immunity and differences in susceptibility within populations.

scholarly journals 410. Influence of Pre-season Antibody Titers to Influenza on Influenza Risk in a Cohort of Healthcare Personnel

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S208-S208
Author(s):  
Susan M Rattigan ◽  
Geoffrey Gorse ◽  
Alexander Kirpich ◽  
Derek Cummings ◽  
Maria C Rodriguez-Barradas ◽  
...  
Keyword(s):  
Influenza A ◽  
Influenza Infection ◽  
Healthcare Personnel ◽  
Influenza B ◽  
Respiratory Protection ◽  
Influenza A H1n1 ◽  
Antibody Titers ◽  
Outpatient Settings ◽  
The Relationship ◽  
Research Grant

Abstract Background Influenza (flu) and other respiratory viruses circulate regularly throughout healthcare systems, often placing healthcare personnel (HCP) at high risk for illness. Hemagglutination inhibition (HAI) titers are associated with protection from flu illness, though few studies have characterized HAI in HCP. The Respiratory Protection Effectiveness Clinical Trial (ResPECT), provided HAI titers and data to assess infection risk based on four flu seasons. Participants from multiple outpatient settings wore respiratory protection within six feet of symptomatic patients. Methods Serological samples obtained at the beginning and end of each season and anterior nasopharyngeal swabs were taken randomly and when participants reported respiratory symptoms were assessed. Our primary outcome was PCR-confirmed influenza. Results During 5,180 participant-seasons of observation, 128 PCR-confirmed influenza A infections (20 H1N1, 108 H3N2) and 34 PCR-confirmed influenza B infections. 4,041 (78%) reported receiving an annual influenza vaccine. Each log base 2 increase in titer subtype-specific titer reduced the hazard of influenza infection with A/H3N2 by 18%(Relative Risk (RR) 0.82 95% CI 0.72,0.94), by 28% for influenza B (RR 0.72 95% CI 0.56,0.92 and by 25% for influenza A H1N1 (RR 0.75 95% CI 0.57–1.0). After adjusting for HAI titers, age was not significantly associated with risk for any of the subtypes. Conclusion In this prospective cohort of monitored HCPs, these findings support the current literature demonstrating that HAI titers are associated with protection from influenza infection. The relationship between HAI titers, influenza, and vaccination is complex, however. Vaccination was not shown to be associated with infection outcome in our model, though their effect may be difficult to separate from their effect on HAI titers. Disclosures Trish M. Perl, MD, MSc, 7–11: Advisory Board; medimmune: Research Grant.

Comparison of Immune Response to the Influenza Vaccine in Obese and Nonobese Healthcare Workers

2015 ◽  
Vol 36 (3) ◽  
pp. 249-253 ◽  
Author(s):  
Michael A. Sweet ◽  
Jonathan A. McCullers ◽  
Paul R. Lasala ◽  
Frank E. Briggs ◽  
Anne Smithmyer ◽  
...  
Keyword(s):  
Influenza Vaccine ◽  
Healthcare Workers ◽  
Influenza A ◽  
Medical Center ◽  
Geometric Mean ◽  
Fold Increase ◽  
Influenza B ◽  
Influenza A H1n1 ◽  
Significant Difference ◽  
Antibody Titers

OBJECTIVETo determine whether there is a difference in antibody titers and functionality after receipt of the influenza vaccine for obese versus nonobese healthcare workers (HCW).DESIGNProspective observational study.SETTINGTertiary medical center.PARTICIPANTSHealthcare workers.METHODSBaseline influenza antibody titers for obese and nonobese HCW were recorded during the hospital’s 2011 annual influenza vaccination day and follow-up antibody titers were measured 4 weeks later. Antibodies were measured using the hemagglutination inhibition assay and functionality was measured using the micro-neutralization method.RESULTSOf 200 initial HCWs, 190 completed the study (97 obese and 93 nonobese). Seroprotection after immunization was not significantly different for nonobese compared with obese HCW for each strain (influenza A [H1N1], 99% and 99%; influenza A [H3N2], 100% and 99%; and influenza B, 67% and 71%, respectively)All geometric mean titers measured by micro-neutralization showed statistically significant increases in activity. In comparison, there was no difference in the 4-fold increase in H1N1 or B titers. There was a significant difference in the 4-fold increase of H3N2 titers between the nonobese and obese HCWs (82/93 [88%] vs 64/97 [66%], P=.003)In an ad hoc analysis we found that obese HCWs had a statistically greater number of 4-fold decreases in titers with H1N1 and H3N2.CONCLUSIONSThere was no significant difference in protection from influenza between obese and nonobese HCWs after immunization.Infect Control Hosp Epidemiol 2014;00(0): 1–5

scholarly journals Assessment of exposure to influenza A viruses in pigs between weaning and market age

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Juliana Bonin Ferreira ◽  
Zvonimir Poljak ◽  
Robert Friendship ◽  
Éva Nagy ◽  
Greg Wideman ◽  
...  
Keyword(s):  
Influenza A ◽  
Production Systems ◽  
Influenza A Viruses ◽  
Ha Gene ◽  
Testing Strategies ◽  
Common Causes ◽  
Nasal Swabs ◽  
Antibody Titers ◽  
2009 H1n1 ◽  
Low Prevalence

AbstractInfluenza A viruses (IAVs) are common causes of respiratory infection in pigs. The objective of this study was to characterize the circulation of IAVs between weaning and market age on the basis of development of antibody response and molecular epidemiology of detected viruses. Two batches of weaned pigs were followed in the nursery and finisher barns with a sample of 81 and 75 pigs. Nasal swabs and blood samples were collected from individual pigs for virological and serological analyses. A H3N2 subtype virus, of cluster IV, was detected in Study 1, with a maximum of 97.9% identity to HA gene of viruses previously isolated in Ontario. In Study 2, a H1N1 subtype virus, of 2009 H1N1 pandemic lineage, was detected, with a maximum of 97.8% identity to HA gene of viruses previously isolated in Ontario. On the basis of HA gene, it was observed that pigs were being detected with the same virus over time. The existence of antibody titers for IAV other than the isolated one confirmed that more than one subtype can circulate in the same population. In Study 1, pigs with higher numbers of IAV detection had lower serological titers for the same virus that was confirmed to circulate in the nursery (P < 0.01). Thorough knowledge of all endemic viral strains is fundamental for development of infection and disease control, particularly in complex production systems. This may include consideration of sampling and testing strategies which could detect circulation of all IAV variants, even if they have low prevalence.

scholarly journals PRESENCE OF RESPIRATORY VIRUSES IN EQUINES IN BRAZIL

2014 ◽  
Vol 56 (3) ◽  
pp. 191-195
Author(s):  
Dalva Assunção Portari Mancini ◽  
Aparecida Santo Pietro Pereira ◽  
Rita Maria Zucatelli Mendonça ◽  
Adelia Hiroko Nagamori Kawamoto ◽  
Rosely Cabette Barbosa Alves ◽  
...  
Keyword(s):  
Influenza A ◽  
Respiratory Viruses ◽  
Influenza Viruses ◽  
Influenza A Viruses ◽  
Equine Influenza ◽  
Hemagglutination Inhibition Test ◽  
Parainfluenza Viruses ◽  
Significant Difference ◽  
Antibody Titers ◽  
The Difference

Equines are susceptible to respiratory viruses such as influenza and parainfluenza. Respiratory diseases have adversely impacted economies all over the world. This study was intended to determine the presence of influenza and parainfluenza viruses in unvaccinated horses from some regions of the state of São Paulo, Brazil. Blood serum collected from 72 equines of different towns in this state was tested by hemagglutination inhibition test to detect antibodies for both viruses using the corresponding antigens. About 98.6% (71) and 97.2% (70) of the equines responded with antibody protective titers (≥ 80 HIU/25µL) H7N7 and H3N8 subtypes of influenza A viruses, respectively. All horses (72) also responded with protective titers (≥ 80) HIU/25µL against the parainfluenza virus. The difference between mean antibody titers to H7N7 and H3N8 subtypes of influenza A viruses was not statistically significant (p > 0.05). The mean titers for influenza and parainfluenza viruses, on the other hand, showed a statistically significant difference (p < 0.001). These results indicate a better antibody response from equines to parainfluenza 3 virus than to the equine influenza viruses. No statistically significant differences in the responses against H7N7 and H3N8 subtypes of influenza A and parainfluenza 3 viruses were observed according to the gender (female, male) or the age (≤ 2 to 20 years-old) groups. This study provides evidence of the concomitant presence of two subtypes of the equine influenza A (H7N7 and H3N8) viruses and the parainfluenza 3 virus in equines in Brazil. Thus, it is advisable to vaccinate equines against these respiratory viruses.

scholarly journals Characterization of a Human H5N1 Influenza A Virus Isolated in 2003

2005 ◽  
Vol 79 (15) ◽  
pp. 9926-9932 ◽  
Author(s):  
Kyoko Shinya ◽  
Masato Hatta ◽  
Shinya Yamada ◽  
Ayato Takada ◽  
Shinji Watanabe ◽  
...  
Keyword(s):  
Hong Kong ◽  
Avian Influenza ◽  
Influenza A Virus ◽  
Influenza A ◽  
Mainland China ◽  
Virus Infections ◽  
Influenza A Viruses ◽  
H5n1 Avian Influenza Virus ◽  
H5n1 Influenza ◽  
Avian Influenza A Virus

ABSTRACT In 2003, H5N1 avian influenza virus infections were diagnosed in two Hong Kong residents who had visited the Fujian province in mainland China, affording us the opportunity to characterize one of the viral isolates, A/Hong Kong/213/03 (HK213; H5N1). In contrast to H5N1 viruses isolated from humans during the 1997 outbreak in Hong Kong, HK213 retained several features of aquatic bird viruses, including the lack of a deletion in the neuraminidase stalk and the absence of additional oligosaccharide chains at the globular head of the hemagglutinin molecule. It demonstrated weak pathogenicity in mice and ferrets but caused lethal infection in chickens. The original isolate failed to produce disease in ducks but became more pathogenic after five passages. Taken together, these findings portray the HK213 isolate as an aquatic avian influenza A virus without the molecular changes associated with the replication of H5N1 avian viruses in land-based poultry such as chickens. This case challenges the view that adaptation to land-based poultry is a prerequisite for the replication of aquatic avian influenza A viruses in humans.

scholarly journals Viral Factors Important for Efficient Replication of Influenza A Viruses in Cells of the Central Nervous System

2019 ◽  
Vol 93 (11) ◽  
Author(s):  
Jurre Y. Siegers ◽  
Marco W. G. van de Bildt ◽  
Zhanmin Lin ◽  
Lonneke M. Leijten ◽  
Rémon A. M. Lavrijssen ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Influenza A ◽  
H5n1 Virus ◽  
Influenza Viruses ◽  
Virus Infections ◽  
Influenza A Viruses ◽  
Cns Disease ◽  
Efficient Replication ◽  
Hpai H5n1 ◽  
In Cells

ABSTRACTCentral nervous system (CNS) disease is one of the most common extrarespiratory tract complications of influenza A virus infections. Remarkably, zoonotic H5N1 virus infections are more frequently associated with CNS disease than seasonal or pandemic influenza viruses. Little is known about the interaction between influenza A viruses and cells of the CNS; therefore, it is currently unknown which viral factors are important for efficient replication. Here, we determined the replication kinetics of a seasonal, pandemic, zoonotic, and lab-adapted influenza A virus in human neuron-like (SK-N-SH) and astrocyte-like (U87-MG) cells and primary mouse cortex neurons. In general, highly pathogenic avian influenza (HPAI) H5N1 virus replicated most efficiently in all cells, which was associated with efficient attachment and infection. Seasonal H3N2 and to a lesser extent pandemic H1N1 virus replicated in a trypsin-dependent manner in SK-N-SH but not in U87-MG cells. In the absence of trypsin, only HPAI H5N1 and WSN viruses replicated. Removal of the multibasic cleavage site (MBCS) from HPAI H5N1 virus attenuated, but did not abrogate, replication. Taken together, our results showed that the MBCS and, to a lesser extent, the ability to attach are important determinants for efficient replication of HPAI H5N1 virus in cells of the CNS. This suggests that both an alternative hemagglutinin (HA) cleavage mechanism and preference for α-2,3-linked sialic acids allowing efficient attachment contribute to the ability of influenza A viruses to replicate efficiently in cells of the CNS. This study further improves our knowledge on potential viral factors important for the neurotropic potential of influenza A viruses.IMPORTANCECentral nervous system (CNS) disease is one of the most common extrarespiratory tract complications of influenza A virus infections, and the frequency and severity differ between seasonal, pandemic, and zoonotic influenza viruses. However, little is known about the interaction of these viruses with cells of the CNS. Differences among seasonal, pandemic, and zoonotic influenza viruses in replication efficacy in CNS cells,in vitro, suggest that the presence of an alternative HA cleavage mechanism and ability to attach are important viral factors. Identifying these viral factors and detailed knowledge of the interaction between influenza virus and CNS cells are important to prevent and treat this potentially lethal CNS disease.

scholarly journals Immunogenicity and safety of a trivalent inactivated influenza vaccine

2011 ◽  
Vol 51 (1) ◽  
pp. 22 ◽  
Author(s):  
Eddy Fadlyana ◽  
Kusnandi Rusmil ◽  
Novilia Sjafri Bachtiar ◽  
Rachmat Gunadi ◽  
Hadyana Sukandar
Keyword(s):  
Influenza Vaccine ◽  
Influenza A ◽  
Geometric Mean ◽  
Deltoid Muscle ◽  
Influenza B ◽  
Serious Adverse Events ◽  
Blood Samples ◽  
Adolescents And Adults ◽  
Antibody Titers ◽  
Influenza Prevention

Background Trivalent inactivated influenza vaccines (TIV) containing antigens of two influenza A strains, A(H1N1) and A(H3N2), and one influenza B strain, are the standard {onnulation for influenza prevention. The vaccines must be updated annually to provide optimal protection against the predicted prevalent strains for the next influenza season.Objective To assess the immunogenidty and safety of the inactivated influenza vaccine (Flubio®) in adolescents and adults, 28 days after a single dose.Methods In this experimental, randomized, single-blind, bridging study, we included 60 healthy adolescents and adults. A single, 0.5 mL dose was administered intramuscularly in the deltoid muscle of the left ann. Blood samples were obtained before and 28 days after immunization. Standardized hemagglutination inhibition (HI) test was used to assess antibody response to influenza antigens.Results From January to February 2010, a total of 60 adolescents and adults enrolled in the study, but two participants did not provide the required blood samples. One hundred percent of the subjects had an anti-influenza titer ≥ 1:40 HI units to all three strains, A/Brisbane/59/2007 (H1N1), A/Uruguay/716/2007 (H3N2), and B/Brisbane/60/2008 (P=1.000) after immunization. The Geometric Mean Titers (GMT) after immunization increasedfor all strains: A/Brisbane, 76.4 to 992.7, A/Uruguay, 27.6 to 432.1, and B/Brisbane, 19.9 to 312.7. Twenty eight days after immunization, we found a 4 times increase in antibody titers in 75.8% of the subjects for A/Brisbane, 84.5% for A/Uruguay, and 77.6% for B/Brisbane. We also observed that 100% of seronegative subjects converted to seropositive for all 3 strains. All vaccines were well-tolerated. There were no serious adverse events reported during the study.Conclusion In adolescents and adults, the Flubio® vaccine was immunogenic and safe.

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

2012 ◽  
Vol 19 (10) ◽  
pp. 1690-1692 ◽  
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.

scholarly journals Obesity Is Associated With Increased Susceptibility to Influenza A (H1N1pdm) but Not H3N2 Infection

2020 ◽  
Author(s):  
Hannah E Maier ◽  
Guillermina Kuan ◽  
Lionel Gresh ◽  
Roger Lopez ◽  
Nery Sanchez ◽  
...  
Keyword(s):  
Influenza A ◽  
Influenza Infection ◽  
High Risk Population ◽  
Virus Infections ◽  
Middle Aged ◽  
Symptomatic Infection ◽  
Logistic Regression Models ◽  
Susceptibility To Infection ◽  
Associated Symptoms ◽  
Increased Susceptibility

Abstract Background Obesity has been shown to increase the risk of severe outcomes and death for influenza virus infections. However, we do not understand the influence of obesity on susceptibility to infection or on nonsevere influenza outcomes. Methods We performed a case-ascertained, community-based study of influenza transmission within households in Nicaragua. To investigate whether obesity increases the likelihood of influenza infection and symptomatic infection we used logistic regression models. Results Between 2015 and 2018, a total of 335 index cases with influenza A and 1506 of their household contacts were enrolled. Obesity was associated with increased susceptibility to symptomatic H1N1pdm infection among adults (odds ratio [OR], 2.10; 95% confidence interval [CI], 1.08–4.06) but not children, and this association increased with age. Among adults with H1N1pdm infection, obesity was associated with increased likelihood of symptoms (OR, 3.91; 95% CI, 1.55–9.87). For middle-aged and older adults with obesity there was also a slight increase in susceptibility to any H1N1pdm infection (OR, 1.20; 95% CI, .62–2.34). Body mass index (BMI) was also linearly associated with increased susceptibility to symptomatic H1N1pdm infection, primarily among middle-aged and older women (5-unit BMI increase OR, 1.40; 95% CI, 1.00–1.97). Obesity was not associated with increased H3N2 susceptibility or associated symptoms. Conclusions We found that, among adults, obesity is associated with susceptibility to H1N1pdm infection and with symptoms associated with H1N1pdm infection, but not with susceptibility to H3N2 infection or associated symptoms. These findings will help target prevention efforts and therapeutics to this high-risk population.

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