Browsing by Subject "Vaccination"

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    Human newborn bacille Calmette–Guérin vaccination and risk of tuberculosis disease: a case-control study
    (2016) Fletcher, Helen A; Filali-Mouhim, Ali; Nemes, Elisa; Hawkridge, Anthony; Keyser, Alana; Njikan, Samuel; Hatherill, Mark; Scriba, Thomas J; Abel, Brian; Kagina, Benjamin M; Veldsman, Ashley; Agudelo, Nancy Marín; Kaplan, Gilla; Hussey, Gregory D; Sekaly, Rafick-Pierre; Hanekom, Willem A
    : An incomplete understanding of the immunological mechanisms underlying protection against tuberculosis (TB) hampers the development of new vaccines against TB. We aimed to define host correlates of prospective risk of TB disease following bacille Calmette-Guérin (BCG) vaccination. : In this study, 5,726 infants vaccinated with BCG at birth were enrolled. Host responses in blood collected at 10 weeks of age were compared between infants who developed pulmonary TB disease during 2 years of follow-up (cases) and those who remained healthy (controls). : Comprehensive gene expression and cellular and soluble marker analysis failed to identify a correlate of risk. We showed that distinct host responses after BCG vaccination may be the reason: two major clusters of gene expression, with different myeloid and lymphoid activation and inflammatory patterns, were evident when all infants were examined together. Cases from each cluster demonstrated distinct patterns of gene expression, which were confirmed by cellular assays. : Distinct patterns of host responses to Mycobacterium bovis BCG suggest that novel TB vaccines may also elicit distinct patterns of host responses. This diversity should be considered in future TB vaccine development.
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    Mobile phone text message reminders to improve vaccination uptake: a systematic review
    (2025) Louw, Gail; Engel, Mark
    Background: Vaccination uptake remains of public health concern, despite reported improvements in vaccine access. Innovative strategies, such as mobile phone text message reminders (MPTMRs), have been explored and implemented globally to facilitate the increase in vaccination uptake and recall rates. This systematic review, employing best practice, evaluated the most recent scientific evidence for the use of MPTMRs as an intervention to improve vaccination uptake. Objective: To evaluate the effectiveness of MPTMRs on vaccination uptake in children, adolescents and adults. Methods: This systematic review included randomized controlled trials (RCT's) of caregivers of children, adolescents or adults who received MPTMRs as an intervention for improving vaccine uptake and recall visits. Studies were excluded if they did not include a comparator group or, if the comparator group was not usual care. Two authors independently searched Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, Scopus, GoogleScholar and ClinicalTrials.gov to identify relevant studies published by 24 January 2024 using a pre-defined search strategy. Included studies were assessed with the Cochrane Collaboration's tool for assessing risk of bias in randomised trials. Given the heterogeneity across studies, pooled risk ratios were estimated using the random-effects model. Subgroup analyses were conducted to assess the effect of intervention type, country's economic status, study setting, and vaccination types on results of the meta-analysis. Results: We identified 25 studies (n = 64 536) for inclusion for quantitative synthesis of evidence regarding vaccination uptake. While studies were considered as having a low risk for random sequence generation, most showed an unclear risk of bias for allocation concealment. Blinding, incomplete outcome data, selective reporting and detection bias were assessed as having a low risk of bias for most studies with high attrition bias observed in seven studies. Pooled data favoured MPTMRs (RR=1.09 [95%CI: 1.06, 1.13], I2 = 76%) for improving vaccination uptake compared to usual care. Exclusion of studies of poor quality assessment improved heterogeneity and maintained the effect (RR=1.05 [95%CI: 1.03, 1.07]; I2 = 33%).