scholarly journals Immunogenicity and waning immunity from the oral cholera vaccine (Shanchol™) in adults residing in Lukanga Swamps of Zambia

PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0262239
Author(s):  
Harriet Ng′ombe ◽  
Michelo Simuyandi ◽  
John Mwaba ◽  
Charlie Chaluma Luchen ◽  
Peter Alabi ◽  
...  
Keyword(s):  
Time Window ◽  
Geometric Mean ◽  
Critical Time ◽  
Serum Samples ◽  
Box Plots ◽  
Antibody Titres ◽  
Oral Cholera Vaccine ◽  
Risk Areas ◽  
Endemic Areas ◽  
Duration Of Protection

Introduction In cholera endemic areas, the periodicity of cholera outbreaks remains unpredictable, making it difficult to organize preventive efforts. Lack of data on duration of protection conferred by oral cholera vaccines further makes it difficult to determine when to deploy preemptive vaccination. We report on the immunogenicity and waning of immunity to Shanchol™ in Lukanga Swamps. Methods We enrolled a cohort of 223 participants aged between 18 and 65 years old from whom serum samples were collected at baseline, day 28 before administration of the second dose, and consecutively at 6, 12, 24, 30, 36, and 48 months. Vibriocidal antibody titres were measured and expressed as geometric mean titres. Box plots and 95% CI were computed at each visit for both Inaba and Ogawa. Seroconversion was defined as a four fold or greater increase in antibody titres compared to baseline titres. Results Overall, seroconversion against V. cholerae Inaba and Ogawa after 1st dose was 35/134 (26%) and 34/134 (25%) respectively. We observed a statistical difference in seroconversion between the two subgroups of baseline titres (low <80 and high ≥80) for both Inaba (p = 0.02) and Ogawa (p<0.0001). From a baseline of 13.58, anti-Ogawa GMT increased to 21.95 after the first dose, but rapidly waned to 14.52, 13.13, and 12.78 at months 6, 12 and 24 respectively, and then increased to 13.21, 18.67 and 23.65 at months 30, 36 and 48 respectively. A similar trend was observed for anti-Inaba GMT across the same time points. Conclusion We found that Shanchol™ was immunogenic in our study population and that vibriocidal antibodies may not be a good marker for long-term immunity. The observed rise in titres after 36 months suggests natural exposure, and this may be a critical time window opening for natural transmission in an endemic areas. We recommend re-vaccination at this time point in high risk areas.

scholarly journals Protection by a polyvalent influenza vaccine and persistence of homologous and heterologous HI antibodies during a period of two epidemic seasons

1980 ◽  
Vol 84 (2) ◽  
pp. 237-245 ◽  
Author(s):  
R. Pyhälä
Keyword(s):  
General Population ◽  
Antibody Response ◽  
Influenza Vaccine ◽  
Influenza A ◽  
Geometric Mean ◽  
Influenza B ◽  
Trial Period ◽  
Serum Samples ◽  
Antibody Titres ◽  
The Individual

SUMMARYA split-product influenza A vaccine which contained an influenza B strain (B/Hong Kong/8/73) and two influenza A strains, antigenically identical with A/Fort Dix/741/76 (HswlNl) and A/Victoria/3/75 (H3N2), was offered to personnel of the CPHL. Changes in the antibody status were followed with serum samples collected from 153 participants on the day of vaccination and 1, 13 and 18 months thereafter. During the two epidemic seasons in the trial period there were only four serological influenza A infections (2·6%) among the vaccinees. This is one eighth of the corresponding infection rate (22%) in the general population estimated on the basis of other indices.The vaccinees' antibody response was strongly influenced by the age of the individual subjects. During the trial period the decrease in the antibody titres slowed down. The geometric mean titres of homologous HI antibodies were still substantially higher at the end of the period than at the beginning. This also applied to heterologous antibodies against H1N1 viruses in persons born between 1926 and 1952. In participants born after 1952, the vaccine was not able to evoke these antibodies, and in participants born in or before 1925 the boosting effect was poor.

scholarly journals Serum anti-tetanus and measles antibody titres in Ugandan children aged 4 months to 6 years: implications for vaccine programme

2018 ◽  
Vol 146 (9) ◽  
pp. 1151-1156 ◽  
Author(s):  
Lenesha Warrener ◽  
Josephine Bwogi ◽  
Nick Andrews ◽  
Dhanraj Samuel ◽  
Theopista Kabaliisa ◽  
...  
Keyword(s):  
Geometric Mean ◽  
Health Clinic ◽  
Antibody Concentration ◽  
Older Children ◽  
Antibody Prevalence ◽  
Protective Level ◽  
Serum Samples ◽  
Child Health Clinic ◽  
Antibody Titres ◽  
Tetanus Antibodies

AbstractTo study the antibody response to tetanus toxoid and measles by age following vaccination in children aged 4 months to 6 years in Entebbe, Uganda. Serum samples were obtained from 113 children aged 4–15 months, at the Mother-Child Health Clinic (MCHC), Entebbe Hospital and from 203 of the 206 children aged between 12 and 75 months recruited through the Outpatients Department (OPD). Antibodies to measles were quantified by plaque reduction neutralisation test (PRNT) and with Siemens IgG EIA. VaccZyme IgG EIA was used to quantify anti-tetanus antibodies. Sera from 96 of 113 (85.0%) children attending the MCHC contained Measles PRNT titres below the protective level (120 mIU/ml). Sera from 24 of 203 (11.8%) children attending the OPD contained PRNT titres <120 mIU/ml. There was no detectable decline in anti-measles antibody concentrations between 1 and 6 years. The anti-tetanus antibody titres in all 113 children attending MCHC and in 189 of 203 (93.1%) children attending the OPD were >0.15 IU/ml by EIA, a level considered protective. The overall concentration of anti-tetanus antibody was sixfold higher in children under 12 months compared with the older children, with geometric mean concentrations of 3.15 IU/ml and 0.49 IU/ml, respectively. For each doubling in age between 4 and 64 months, the anti-tetanus antibody concentration declined by 50%. As time since the administration of the third DTP vaccination doubled, anti-tetanus antibody concentration declined by 39%. The low measles antibody prevalence in the children presenting at the MCHC is consistent with the current measles epidemiology in Uganda, where a significant number of measles cases occur in children under 1 year of age and earlier vaccination may be indicated. The consistent fall in anti-tetanus antibody titre over time following vaccination supports the need for further vaccine boosters at age 4–5 years as recommended by the WHO.

scholarly journals Vaccination strategy and anti - SARS-CoV-2 S titers in healthcare workers of the INT – IRCCS “Fondazione Pascale” Cancer Center (Naples, Italy)

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Ernesta Cavalcanti ◽  
Maria Antonietta Isgrò ◽  
Domenica Rea ◽  
Lucia Di Capua ◽  
Giusy Trillò ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Healthcare Workers ◽  
Geometric Mean ◽  
Vaccination Strategy ◽  
Antibody Responses ◽  
Cancer Center ◽  
Serum Samples ◽  
Humoral Immune ◽  
History Of

Abstract Background Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection and the resulting disease, coronavirus disease 2019 (COVID-19), have spread to millions of people globally, requiring the development of billions of different vaccine doses. The SARS-CoV-2 spike mRNA vaccine (named BNT162b2/Pfizer), authorized by the FDA, has shown high efficacy in preventing SARS-CoV-2 infection after administration of two doses in individuals 16 years of age and older. In the present study, we retrospectively evaluated the differences in the SARS-CoV-2 humoral immune response after vaccine administration in the two different cohorts of workers at the INT - IRCCS “Fondazione Pascale” Cancer Center (Naples, Italy): previously infected to SARS-CoV-2 subjects and not infected to SARS-CoV-2 subjects. Methods We determined specific anti-RBD (receptor-binding domain) titers against trimeric spike glycoprotein (S) of SARS-CoV-2 by Roche Elecsys Anti-SARS-CoV-2 S immunoassay in serum samples of 35 healthcare workers with a previous documented history of SARS-CoV-2 infection and 158 healthcare workers without, after 1 and 2 doses of vaccine, respectively. Moreover, geometric mean titers and relative fold changes (FC) were calculated. Results Both previously infected and not infected to SARS-CoV-2 subjects developed significant immune responses to SARS-CoV-2 after the administration of 1 and 2 doses of vaccine, respectively. Anti-S antibody responses to the first dose of vaccine were significantly higher in previously SARS-CoV-2-infected subjects in comparison to titers of not infected subjects after the first as well as the second dose of vaccine. Fold changes for subjects previously infected to SARS-CoV-2 was very modest, given the high basal antibody titer, as well as the upper limit of 2500.0 BAU/mL imposed by the Roche methods. Conversely, for naïve subjects, mean fold change following the first dose was low ($$ \overline{x} $$ x ¯ =1.6), reaching 3.8 FC in 72 subjects (45.6%) following the second dose. Conclusions The results showed that, as early as the first dose, SARS-CoV-2-infected individuals developed a remarkable and statistically significant immune response in comparison to those who did not contract the virus previously, suggesting the possibility of administering only one dose in previously SARS-CoV-2-infected subjects. FC for previously infected subjects should not be taken into account for the generally high pre-vaccination values. Conversely, FC for not infected subjects, after the second dose, were = 3.8 in > 45.0% of vaccinees, and ≤ 3.1 in 19.0%, the latter showing a potential susceptibility to further SARS-CoV-2 infection.

scholarly journals Antibody titers measured by commercial assays are correlated with neutralizing antibody titers calibrated by international standards

2021 ◽  
Author(s):  
Yu-An Kung ◽  
Chung-Guei Huang ◽  
Sheng-Yu Huang ◽  
Kuan-Ting Liu ◽  
Peng-Nien Huang ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
Geometric Mean ◽  
Neutralizing Antibody ◽  
Diagnostic Techniques ◽  
International Standards ◽  
World Health ◽  
Serum Samples ◽  
Antibody Titers ◽  
Health Organization

The World Health Organization (WHO) has highlighted the importance of an international standard (IS) for SARS-CoV-2 neutralizing antibody titer detection, with the aim of calibrating different diagnostic techniques. In this study, IS was applied to calibrate neutralizing antibody titers (IU/mL) and binding antibody titers (BAU/mL) in response to SARS-CoV-2 vaccines. Serum samples were collected from participants receiving the Moderna (n = 20) and Pfizer (n = 20) vaccines at three time points: pre-vaccination, after one dose, and after two doses. We obtained geometric mean titers of 1404.16 and 928.75 IU/mL for neutralizing antibodies after two doses of the Moderna and Pfizer vaccines, respectively. These values provide an important baseline for vaccine development and the implementation of non-inferiority trials. We also compared three commercially available kits from Roche, Abbott, and MeDiPro for the detection of COVID-19 antibodies based on binding affinity to S1 and/or RBD. Our results demonstrated that antibody titers measured by commercial assays are highly correlated with neutralizing antibody titers calibrated by IS.

scholarly journals Time-Varying Associations Between an Exposure History and a Subsequent Health Outcome: A landmark Approach to Identify Critical Windows.

2021 ◽  
Author(s):  
Maude Wagner ◽  
Francine Grodstein ◽  
Karen Leffondre ◽  
Cécilia Samieri ◽  
Cécile Proust-Lima
Keyword(s):  
Risk Factors ◽  
Health Outcome ◽  
Measurement Errors ◽  
Mixed Model ◽  
Time Window ◽  
Time Windows ◽  
Critical Time ◽  
Cumulative Exposure ◽  
Exposure Measurement ◽  
Exposure History

Abstract Background: Long-term behavioral and health risk factors constitute a primary focus of research on the etiology of chronic diseases. Yet, identifying critical time-windows during which risk factors have the strongest impact on disease risk is challenging. To assess the trajectory of association of an exposure history with an outcome, the weighted cumulative exposure index (WCIE) has been proposed, with weights reflecting the relative importance of exposures at different times. However, WCIE is restricted to a complete observed error-free exposure whereas exposures are often measured with intermittent missingness and error. Moreover, it rarely explores exposure history that is very distant from the outcome as usually sought in life-course epidemiology.Methods: We extend the WCIE methodology to (i) exposures that are intermittently measured with error, and (ii) contexts where the exposure time-window precedes the outcome time-window using a landmark approach. First, the individual exposure history up to the landmark time is estimated using a mixed model that handles missing data and error in exposure measurement, and the predicted complete error-free exposure history is derived. Then the WCIE methodology is applied to assess the trajectory of association between the predicted exposure history and the health outcome collected after the landmark time. In our context, the health outcome is a longitudinal marker analyzed using a mixed model.Results: A simulation study first demonstrates the correct inference obtained with this approach. Then, applied to the Nurses’ Health Study (19,415 women) to investigate the association between body mass index history (collected from midlife) and subsequent cognitive decline (evaluated after age 70), the method identified two major critical windows of association: long before the first cognitive evaluation (roughly 24 to 12 years), higher levels of BMI were associated with poorer cognition. In contrast, adjusted for the whole history, higher levels of BMI became associated with better cognition in the last years prior to the first cognitive interview, thus reflecting reverse causation (changes in exposure due to underlying disease).Conclusions: This approach, easy to implement, provides a flexible tool for studying complex dynamic relationships and identifying critical time windows while accounting for exposure measurement errors.

scholarly journals Serodiagnosis of Louse-Borne Relapsing Fever with Glycerophosphodiester Phosphodiesterase (GlpQ) fromBorrelia recurrentis

2000 ◽  
Vol 38 (10) ◽  
pp. 3561-3571 ◽  
Author(s):  
Stephen F. Porcella ◽  
Sandra J. Raffel ◽  
Merry E. Schrumpf ◽  
Martin E. Schriefer ◽  
David T. Dennis ◽  
...  
Keyword(s):  
Serological Test ◽  
Geometric Mean ◽  
Eastern Africa ◽  
Enzyme Linked Immunosorbent Assay ◽  
Relapsing Fever ◽  
Serum Samples ◽  
Serological Tests ◽  
Whole Cell ◽  
Convalescent Phase ◽  
Glycerophosphodiester Phosphodiesterase

Human louse-borne relapsing fever occurs in sporadic outbreaks in central and eastern Africa that are characterized by significant morbidity and mortality. Isolates of the causative agent,Borrelia recurrentis, were obtained from the blood of four patients during a recent epidemic of the disease in southern Sudan. TheglpQ gene, encoding glycerophosphodiester phosphodiesterase, from these isolates was sequenced and compared with the glpQ sequences obtained from other relapsing-fever spirochetes. Previously we showed that GlpQ of Borrelia hermsii is an immunogenic protein with utility as a serological test antigen for discriminating tick-borne relapsing fever from Lyme disease. In the present work, we cloned and expressed theglpQ gene from B. recurrentis and used recombinant GlpQ in serological tests. Acute- and convalescent-phase serum samples obtained from 42 patients with louse-borne relapsing fever were tested with an indirect immunofluorescence assay (IFA) and an enzyme-linked immunosorbent assay (ELISA) that used whole cells ofB. recurrentis and with immunoblotting to whole-cell lysates of the spirochete and Escherichia coli producing recombinant GlpQ. The geometric mean titers of the acute- and convalescent-phase serum samples measured by IFA were 1:83 and 1:575, respectively. The immunoblot analysis identified a high level of reactivity and seroconversion to GlpQ, and the assay was more sensitive than the whole-cell IFA and ELISA using purified, recombinant histidine-tagged GlpQ. Serum antibodies to GlpQ and other antigens persisted for 27 years in one patient. We conclude that assessment of anti-GlpQ antibodies will allow serological confirmation of louse-borne relapsing fever and determination of disease prevalence.

scholarly journals Clinical Evaluation of Herbal Medicine (ICH-012) in Treating Acute Cerebral Haemorrhage: Safety and Efficacy from 6- to 72-Hour Time Window (CRRICHTrial-II)

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Qixin Zhang ◽  
Liling Zeng ◽  
Xiuyan Chen ◽  
Yuexiang Zhou ◽  
Baoying Gong ◽  
...  
Keyword(s):  
Herbal Medicine ◽  
Ct Scan ◽  
Time Window ◽  
Rapid Change ◽  
Herbal Medicines ◽  
Critical Time ◽  
Cerebral Haemorrhage ◽  
High Morbidity ◽  
Safety And Efficacy ◽  
Link Type

Background. Hypertensive intracerebral haemorrhage (HICH), which is characterized by rapid change, high morbidity, and mortality, is extremely dangerous. Both medical and surgical treatments lack definitive evidence and remain controversial. A prospective RCT that we have conducted has shown that the usage of the herbal medicine ICH-012 within 6 h of the event may increase the risk of haematoma enlargement and gastrointestinal bleeding. However, the volume of haematoma remains stable after 6 h. Thus, we will increase the time window to the period from 6 to 72 h after onset to evaluate the safety and efficacy of ICH-012 treating ICH (ClinicalTrial.gov ID: NCT03354026). Methods/Design. The CRRICHTrial-II study, a prospective, double-blinded, controlled, multicentre RCT, includes three groups: A, B, and C. Group A patients were treated with 8 herbal medicines (with 2 herbal medicines of Hirudo and Tabanus as well as 6 other combined herbal medicines of Group B) and Group C were placebo. Patients should meet all the inclusion criteria: age between 18 and 80 and diagnosis of HICH by brain CT scan between 6 and 72 h from the onset. The CT scan will be taken at four critical time points: baseline, between 6 and 72h, 24h after onset, and between 10 and 14 days after onset. The drug intervention lasts 10 days, and there is a follow-up visit taken after 90 days. The haematoma enlargement after 24 h onset as demonstrated by CT is the primary outcome. Discussion. A large amount of data from high-quality RCTs is needed for the extensive clinical application of herbal medicine. The CRRICHTrial-II will evaluate the safety and effectiveness of ICH-012 in a safer time window between 6 and 72 h and investigate the possible mechanisms of action and direction of herbal medicine in the haematoma growth after HICH. Trial registration at ClinicalTrial.gov, ID: NCT03354026, is registered on 23rd Nov. 2017.

Sign in / Sign up

Export Citation Format

Share Document