Measles in the Future?

PEDIATRICS ◽  
1983 ◽  
Vol 71 (3) ◽  
pp. 465-465
Author(s):  
C. E. HEALY ◽  
WELBORN CLINIC
Keyword(s):  
Failure Rate ◽  
Hemagglutination Inhibition ◽  
Neutralizing Antibodies ◽  
Immunization Practice ◽  
Large Pool ◽  
The Future

To the Editor.— I am concerned about measles immunization in that most studies show up to a 5% failure rate with the current immunization practice, at least as measured by the hemagglutination-inhibition (HI) technique. Some of these children might be protected by neutralizing antibodies or cellular (lymphocytic)-mediated immunity, but the extent and duration of this immunity, if any, is unknown. HI immunity is apparently permanent. The end result of the current immunization practice will be a large pool of hundreds of thousands and eventually, millions of adults, who will be susceptible to measles.

scholarly journals A Higher-Order N-gram Model to Enhance Automatic Word Prediction for Assamese Sentences Containing Ambiguous Words

2019 ◽  
Vol 8 (6) ◽  
pp. 2921-2926 ◽  
Keyword(s):  
Prediction Model ◽  
Predictive Model ◽  
Failure Rate ◽  
Predictive Models ◽  
Traditional Model ◽  
Word Prediction ◽  
Ambiguous Words ◽  
The Future ◽  
Model Improvement ◽  
N Gram

Word prediction is a technique which tries to suggest the users’ words after knowing the few input letters of the user. This predictive model also tries to generate the future words or next words of a sentence by observing earlier words of the sentence. In this research, two problems are combined, one is word prediction and the next is handling of ambiguous words. A word prediction model predicts the future words of a sentence by using n-gram based model. In general, predictive models use unigram, bigram or trigram models to predict the next words. In case of sentences consisting of ambiguous words, the predictive model by using only bigram or trigram cannot perform well to predict the next words. To enhance this prediction for ambiguous words, maximum of six previous input words are observed and try to predict almost the exact words after the ambiguous words in those particular contexts. Different level of experiments are done and the results are compared for modified or enhanced prediction model with the traditional prediction model, improvement on accuracy and failure rate are found in the enhanced model. The accuracy of the Traditional Model is 60.68% on the hand the accuracy of the Enhanced Model is 66.88%. The failure rate of the Traditional Model is 32.35% and the Enhanced Model is 29.17%

scholarly journals Timeline of SARS-CoV2 spread in Italy: results from an independent serological retesting

2021 ◽  
Author(s):  
Emanuele Montomoli ◽  
Giovanni Apolone ◽  
Alessandro Manenti ◽  
Mattia Boeri ◽  
Paola Suatoni ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Virus Dynamics ◽  
Blood Samples ◽  
Independent Evaluation ◽  
Igg Binding ◽  
Short Period ◽  
The Future ◽  
One Year ◽  
Virus Spreading ◽  
Control Samples

The massive emergence of COVID19 cases in the first phase of pandemic within an extremely short period of time suggest that an undetected earlier circulation of SARS-CoV-2 might have occurred, as documented by several papers in different countries, including a few that reported positive cases even earlier the first cases identified in Wuhan. Given the importance of this evidence, an independent evaluation was recommended. Here we report the results of SARS-CoV-2 antibodies blind retesting of blood samples collected in the prepandemic period in Italy, and in control samples collected one year before, by two independent centers. Results suggest the presence of SARS-CoV-2 antibodies in some samples collected in the prepandemic period, though the detection of IgM and/or IgG binding and neutralizing antibodies is strongly dependent on the different serological assays and thresholds employed, while being absent in control samples collected one year before. These findings highlight the importance of harmonizing serological assays for testing SARS-CoV-2 virus spreading and may contribute to a better understanding the future virus dynamics.

scholarly journals LACK OF IDENTITY IN NEUTRALIZING AND HEMAGGLUTINATION-INHIBITING ANTIBODIES AGAINST INFLUENZA VIRUSES

1950 ◽  
Vol 91 (1) ◽  
pp. 65-86 ◽  
Author(s):  
Duard L. Walker ◽  
Frank L. Horsfall
Keyword(s):  
Influenza Virus ◽  
Hemagglutination Inhibition ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Immune Serum ◽  
Influenza Viruses ◽  
In Ovo ◽  
Neutralization Line

There is an exponential linear relationship between the quantity of influenza virus neutralized and the quantity of immune serum employed in in ovo neutralization. The slope of the neutralization line is extremely steep. The concentration of neutralizing antibody can be measured with considerable precision in ovo if the constant virus-varying serum technique is utilized. The amounts of hemagglutination-inhibiting and neutralizing antibodies which are absorbed by a given quantity of influenza virus (PR8) were found to be predictable and the degree of reactivity of these two antibodies was shown to be directly related to the extent of immunization. It was demonstrated that there are marked discrepancies in correlation between antibody titers obtained by in vitro hemagglutination-inhibition and in vivo neutralization techniques and that neutralizing antibody is preferentially absorbed by a given quantity of virus. Inasmuch as the results were found not to be attributable to peculiarities of the techniques employed, it appears that the antibodies measured by hemagglutination-inhibition in vitro and by neutralization in vivo are not identical.

scholarly journals Early post-infection treatment of SARS-CoV-2 infected macaques with human convalescent plasma with high neutralizing activity reduces lung inflammation

2021 ◽  
Author(s):  
Koen K.A. Van Rompay ◽  
Katherine J. Olstad ◽  
Rebecca L. Sammak ◽  
Joseph Dutra ◽  
Jennifer K. Watanabe ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Virus Replication ◽  
Lung Inflammation ◽  
Neutralizing Antibodies ◽  
Rhesus Macaques ◽  
High Titer ◽  
Natural Infection ◽  
Hospitalized Patients ◽  
Controlled Trials ◽  
The Future

ABSTRACTEarly in the SARS-CoV-2 pandemic, there was a high level of optimism based on observational studies and small controlled trials that treating hospitalized patients with convalescent plasma from COVID-19 survivors (CCP) would be an important immunotherapy. However, as more data from controlled trials became available, the results became disappointing, with at best moderate evidence of efficacy when CCP with high titers of neutralizing antibodies was used early in infection. To better understand the potential therapeutic efficacy of CCP, and to further validate SARS-CoV-2 infection of macaques as a reliable animal model for testing such strategies, we inoculated 12 adult rhesus macaques with SARS-CoV-2 by intratracheal and intranasal routes. One day later, 8 animals were infused with pooled human CCP with a high titer of neutralizing antibodies (RVPN NT50 value of 3,003), while 4 control animals received normal human plasma. Animals were monitored for 7 days. Animals treated with CCP had detectable levels of antiviral antibodies after infusion. In comparison to the control animals, they had similar levels of virus replication in the upper and lower respiratory tract, but had significantly reduced interstitial pneumonia, as measured by comprehensive lung histology. By highlighting strengths and weaknesses, data of this study can help to further optimize nonhuman primate models to provide proof-of-concept of intervention strategies, and guide the future use of convalescent plasma against SARS-CoV-2 and potentially other newly emerging respiratory viruses.Author summaryThe results of treating SARS-CoV-2 infected hospitalized patients with COVID-19 convalescent plasma (CCP), collected from survivors of natural infection, have been disappointing. The available data from various studies indicate at best moderate clinical benefits only when CCP with high titer of neutralizing antibodies was infused early in infection. The macaque model of SARS-CoV-2 infection can be useful to gain further insights in the value of CCP therapy. In this study, animals were infected with SARS-CoV-2 and the next day, were infused with pooled human convalescent plasma, selected to have a very high titer of neutralizing antibodies. While administration of CCP did not result in a detectable reduction in virus replication in the respiratory tract, it significantly reduced lung inflammation. These data, combined with the results of monoclonal antibody studies, emphasize the need to use products with high titers of neutralizing antibodies, and guide the future development of CCP-based therapies.

Rubella Susceptibility in Sixth Graders: Effectiveness of Current Immunization Practice

PEDIATRICS ◽  
1980 ◽  
Vol 65 (6) ◽  
pp. 1086-1089
Author(s):  
Michael R. Lawless ◽  
Jon S. Abramson ◽  
Joseph E. Harlan ◽  
Doris S. Kelsey
Keyword(s):  
Hemagglutination Inhibition ◽  
Health Department ◽  
Sixth Grade ◽  
Sixth Graders ◽  
Childhood Immunization ◽  
Immunization Practice ◽  
Sixth Grade Students ◽  
Inhibition Antibody ◽  
Mass Immunization ◽  
Vaccine Failures

Rubella hemagglutination inhibition antibody titer was determined for 702 sixth grade students from nine randomly chosen schools in a community served well medically. Rubella immunization had been given by private physicians, the health department, hospital clinics, and through a mass immunization effort in 1970. The overall susceptibility rate, as defined by a rubella hemagglutination inhibition titer of less than 1:8, was 15%. Susceptibility did not differ significantly in regard to sex, race, or source of vaccine. Of 469 children with a documented rubella immunization, 13.2% were susceptible or vaccine failures. Menarche was reported by 30% of the girls. To increase the level of protection against rubella during the childbearing years, continued emphasis on early childhood immunization combined with consideration of a booster rubella immunization for preadolescents is recommended.

scholarly journals Immunodominance of Antigenic Site B in the Hemagglutinin of the Current H3N2 Influenza Virus in Humans and Mice

2018 ◽  
Vol 92 (20) ◽  
Author(s):  
Felix Broecker ◽  
Sean T. H. Liu ◽  
Weina Sun ◽  
Florian Krammer ◽  
Viviana Simon ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Hemagglutination Inhibition ◽  
Neutralizing Antibodies ◽  
Antigenic Site ◽  
Influenza Viruses ◽  
Antigenic Sites ◽  
Head Domain ◽  
Hemagglutinin Protein ◽  
H3n2 Influenza ◽  
H3n2 Influenza Virus

ABSTRACTThe hemagglutinin protein of H3N2 influenza viruses is the major target of neutralizing antibodies induced by infection and vaccination. However, the virus frequently escapes antibody-mediated neutralization due to mutations in the globular head domain. Five topologically distinct antigenic sites in the head domain of H3 hemagglutinin, A to E, have been previously described by mapping the binding sites of monoclonal antibodies, yet little is known about the contribution of each site to the immunogenicity of modern H3 hemagglutinins, as measured by hemagglutination inhibition activity, which is known to correlate with protection. To investigate the hierarchy of antibody immunodominance, five Δ1 recombinant influenza viruses expressing hemagglutinin of the A/Hong Kong/4801/2014 (H3N2) strain with mutations in single antigenic sites were generated. Next, the Δ1 viruses were used to determine the hierarchy of immunodominance by measuring the hemagglutination inhibition reactivity of mouse antisera and plasma from 18 human subjects before and after seasonal influenza vaccination in 2017-2018. In both mice and humans, mutations in antigenic site B caused the most significant decrease in hemagglutination inhibition titers compared to wild-type hemagglutinin. This study revealed that antigenic site B is immunodominant in the H3N2 influenza virus strain included in the current vaccine preparations.IMPORTANCEInfluenza viruses rapidly evade humoral immunity through antigenic drift, making current vaccines poorly effective and antibody-mediated protection short-lived. The majority of neutralizing antibodies target five antigenic sites in the head domain of the hemagglutinin protein that are also the most sequence-variable regions. A better understanding of the contribution of each antigenic site to the overall antibody response to hemagglutinin may help in the design of improved influenza virus vaccines.

On some characteristics of quality for systems operating in a random environment

2018 ◽  
Vol 233 (2) ◽  
pp. 257-267
Author(s):  
Ji Hwan Cha ◽  
Maxim Finkelstein
Keyword(s):  
Stochastic Process ◽  
Failure Rate ◽  
Random Environment ◽  
Process Performance ◽  
Output Function ◽  
Quality Function ◽  
Shock Process ◽  
Monotonicity Properties ◽  
The Future

We consider systems that are operating in a random environment modeled by an external shock process. Performance of a system is characterized by a quality (output) function that is decreasing (due to degradation) in the absence of shocks. The important feature of our model is that shocks affect the failure rate of a system directly, and at the same time, each shock contributes to the additional decrease in the quality function forming the corresponding stochastic process. Expectations (unconditional and conditional on survival) and variability of this process are analyzed. Some monotonicity properties of the conditional quality function are discussed and expressions for the future values of this function are derived.

Antibodies to the California group of arboviruses in animal populations of New Brunswick

1982 ◽  
Vol 28 (2) ◽  
pp. 200-204 ◽  
Author(s):  
B. L. McFarlane ◽  
J. E. Embree ◽  
J. A. Embil ◽  
K. R. Rozee ◽  
H. Artsob
Keyword(s):  
North America ◽  
New Brunswick ◽  
Hemagglutination Inhibition ◽  
Neutralizing Antibodies ◽  
Domestic Animals ◽  
Snowshoe Hare ◽  
Northeastern North America ◽  
Animal Populations ◽  
Antibody Titers ◽  
Horse Blood

Wild and domestic animals of New Brunswick were tested serologically for antibodies to the California group (CAL) of arboviruses. Deer (Odocoileus virginianus) blood collected during 1976 showed 6 of 129 (4.7%) sera with neutralizing antibodies to the snowshoe hare strain (SSH) of CAL. Neutralization tests on moose (Alces alces americana Clinton) sera collected during 1979 indicated 94 of 127 (74%) with antibodies to SSH, 4 of 127 (3.2%) with antibodies to the Jamestown Canyon strain (JC) of CAL, and 17 of 127 (13.4%) with equal antibody titers to SSH and JC. Hemagglutination inhibition tests on horse blood collected during 1977 showed 54 of 204 (26.5 %) with antibodies to SSH; of these, 36 also had neutralizing antibodies to SSH. This study is the first indication of CAL activity in New Brunswick and supports evidence of JC activity in northeastern North America.

A rapid fluorescent focus-inhibition test for determining dengue neutralizing antibody and for identifying prototype dengue viruses

1978 ◽  
Vol 24 (12) ◽  
pp. 1553-1556 ◽  
Author(s):  
W. Lanier Thacker ◽  
Vester J. Lewis ◽  
George M. Baer ◽  
Gladys E. Sather
Keyword(s):  
Dengue Virus ◽  
Hemagglutination Inhibition ◽  
Neutralizing Antibodies ◽  
Complement Fixation ◽  
Neutralizing Antibody ◽  
Inhibition Test ◽  
Dengue Viruses ◽  
Reduction Test ◽  
Antibody Titers ◽  
Fluorescent Focus

Neutralizing antibody to dengue virus in human and animal sera was assayed by the rapid fluorescent focus-inhibition test (RFFIT). Neutralizing-antibody titers could be detected after only 24 h compared to 5–6 days required by the plaque-reduction test. The RFFIT is more definitive than the conventional complement fixation (CF) or hemagglutination-inhibition (HI) test in identifying prototype dengue viruses, is reproducible, and is applicable to the routine detection of neutralizing antibodies to dengue viruses.

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