Serotype-Specific Correlates of Protection for Pneumococcal Carriage: An Analysis of Immunity in 19 Countries

Voysey, Merryn; Fanshawe, Thomas R; Kelly, Dominic F.; O’Brien, Katherine L.; Kandasamy, Rama; Shrestha, Shrijana; Thorson, Stephen; Hinds, Jason; Pollard, Andrew J.

doi:10.1093/cid/cix895

Cited by 47 publications

(69 citation statements)

References 31 publications

(44 reference statements)

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“…1 According to World Health Organization, immunization has prevented 2 to 3 million deaths each yea. 2 However, despite of often-time strong evidence on the efficacy of immunization, some of the world population still does not receive necessary immunization, including many children (e.g., 19.4 million children did not receive BCG and DPT in the same WHO report as above). 2 Different from resource-deprived countries where the major challenge on not receiving vaccination is lack of necessary healthcare system and infrastructure, in industrialized countries, vaccination is provided on a voluntary basis and thus not having immunization is usually due to the negligence and ignorance.…”

Section: Introductionmentioning

confidence: 99%

“…8,11 Solutions also include addressing parents' concerns about vaccines and providing high-quality vaccination services at school or community hospitals. 2,3,8 Research shows that parental acceptance and attitudes are important determinants of children immunization. Regarding influenza vaccination, studies suggest that parents' refusal to vaccinate children is mainly due to perceived barriers, including suspicion of validity and the fear of possible adverse events.…”

Section: Introductionmentioning

confidence: 99%

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Predicting behavioral intentions to children vaccination among Chinese parents: an extended TPB model

Min

Zhao

Kong

et al. 2018

Human Vaccines & Immunotherapeutics

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Parental behavioral intentions play a key role in children vaccination. The present study looks at how parental expectations for the vaccination influence their attitudes and behavioral intentions toward children's immunization. The theoretical model is developed on TPB model and empirically tested with sample data from 380 children aged 0-7 years in mainland China. The structural equation modeling and multi-group analysis were used in the model to demonstrate the impact of the vaccination services quality, vaccination promotions and public opinions on attitudes and vaccination behavioral intention. Results support the study's hypotheses and indicate that Vaccination Services Quality (VSQ), Vaccination Promotions (VAP) and Public Opinions (PUO) have positive effects on Attitudes (ATT) and Vaccination Behavioral Intention (VAI), VSQ has the strongest standardized path (.594) while PUO has the least influence (.131), and Attitude is complete mediation in all paths. Attitude is key factor that determine the parental behavioral intentions, and the internal perception comes from the vaccination services quality and the external influence comes from the social environment affect the parental attitude. Governments should implement effective policies and improve vaccination services quantity to eliminate parental misunderstandings.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Predicting behavioral intentions to children vaccination among Chinese parents: an extended TPB model

Min

Zhao

Kong

et al. 2018

Human Vaccines & Immunotherapeutics

View full text Add to dashboard Cite

show abstract

“…Clear instances of disease occurring in the presence of high antibody levels have been observed [ 18 ] as well as serotype-specific differences in protective levels for pneumococcal vaccines. [ 11 , 19 , 20 ] However, this method has been used to establish licensure for more than one vaccine that has subsequently proven to be effective and thus defining the original threshold was a useful process which led to successful vaccine development. [ 14 , 21 – 23 ]…”

Section: Discussionmentioning

confidence: 99%

“…We have previously modelled the relationship between pneumococcal carriage infection and antibody response to vaccination in infants, revealing that a point at which the probability of carriage becomes negligible does exist for most serotypes and the levels vary between them. [ 20 ] Thus for some (in particular polysaccharide capsular conjugate) vaccines a true threshold of absolute protection may exist. However, for other organisms the relationship between antibody and infection may be different due to different underlying immunological processes, such as for live attenuated viral vaccines or intracellular pathogens.…”

Section: Discussionmentioning

confidence: 99%

“…This has been done successfully for pneumococcal carriage studies. [ 19 , 20 ] However, these models require suitable numbers of events to appropriately characterise the shape of the relationship and cannot therefore be used when modelling rare events such as blood culture positive enteric fever or invasive bacterial diseases. In these situations, models based on serological methods for detecting disease events show greater promise.…”

Section: Discussionmentioning

confidence: 99%

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Computing threshold antibody levels of protection in vaccine clinical trials: An assessment of methodological bias

et al. 2018

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In the development of new vaccines, understanding the level of vaccine-induced antibody that is sufficient to protect against disease can simplify and expedite the development and licensing process. If there is an accepted threshold antibody level that is indicative of protection, then smaller trials measuring antibody concentration alone can be conducted to test new vaccines, instead of large efficacy studies powered on clinical outcomes. Commonly, threshold levels of protective antibody are determined from clinical efficacy trials in which clinical endpoints are measured on everyone and a small subset of participants have antibody concentrations measured. The proportion of participants with antibody below a threshold in each group in the immunogenicity subset can be compared to the proportions with disease in each group in the larger trial to find an appropriate threshold. Mathematically, this method seeks to compute an absolute threshold whereby antibody above the threshold provides complete, sterilizing immunity. However, in practice it is often understood that such thresholds may only be indicative of a relative degree of protection rather than an absolute one. Although this approach is common, the accuracy of such methods when the underlying mathematical assumptions do not hold true, has never been tested. We simulated data from clinical trial scenarios under varying assumptions of vaccine efficacy and calculated antibody thresholds of protection. We estimated the bias in the calculated thresholds derived from each scenario and showed that in many situations this method produces inflated estimates of thresholds, particularly if a vaccine induces high levels of antibody or when the underlying assumption of sterilizing immunity is violated.

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Ageing Mucosal Immunity and Its Consequences for Infectious Diseases in the Aged; A First Glance

Heiden¹,

Baarle²

2021

Healthy Ageing and Longevity

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Serotype-Specific Correlates of Protection for Pneumococcal Carriage: An Analysis of Immunity in 19 Countries

Cited by 47 publications

References 31 publications

Predicting behavioral intentions to children vaccination among Chinese parents: an extended TPB model

Predicting behavioral intentions to children vaccination among Chinese parents: an extended TPB model

Computing threshold antibody levels of protection in vaccine clinical trials: An assessment of methodological bias

Ageing Mucosal Immunity and Its Consequences for Infectious Diseases in the Aged; A First Glance

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