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Clinical Infectious Diseases : An... Jun 2020Diphtheria, once a major cause of childhood morbidity and mortality, all but disappeared following introduction of diphtheria vaccine. Recent outbreaks highlight the...
BACKGROUND
Diphtheria, once a major cause of childhood morbidity and mortality, all but disappeared following introduction of diphtheria vaccine. Recent outbreaks highlight the risk diphtheria poses when civil unrest interrupts vaccination and healthcare access. Lack of interest over the last century resulted in knowledge gaps about diphtheria's epidemiology, transmission, and control.
METHODS
We conducted 9 distinct systematic reviews on PubMed and Scopus (March-May 2018). We pooled and analyzed extracted data to fill in these key knowledge gaps.
RESULTS
We identified 6934 articles, reviewed 781 full texts, and included 266. From this, we estimate that the median incubation period is 1.4 days. On average, untreated cases are colonized for 18.5 days (95% credible interval [CrI], 17.7-19.4 days), and 95% clear Corynebacterium diphtheriae within 48 days (95% CrI, 46-51 days). Asymptomatic carriers cause 76% (95% confidence interval, 59%-87%) fewer cases over the course of infection than symptomatic cases. The basic reproductive number is 1.7-4.3. Receipt of 3 doses of diphtheria toxoid vaccine is 87% (95% CrI, 68%-97%) effective against symptomatic disease and reduces transmission by 60% (95% CrI, 51%-68%). Vaccinated individuals can become colonized and transmit; consequently, vaccination alone can only interrupt transmission in 28% of outbreak settings, making isolation and antibiotics essential. While antibiotics reduce the duration of infection, they must be paired with diphtheria antitoxin to limit morbidity.
CONCLUSIONS
Appropriate tools to confront diphtheria exist; however, accurate understanding of the unique characteristics is crucial and lifesaving treatments must be made widely available. This comprehensive update provides clinical and public health guidance for diphtheria-specific preparedness and response.
Topics: Child; Diphtheria; Disease Outbreaks; Humans; Vaccination
PubMed: 31425581
DOI: 10.1093/cid/ciz808 -
Vaccine Aug 2015The purpose of this systematic review is to identify, describe and assess the potential effectiveness of strategies to respond to issues of vaccine hesitancy that have... (Review)
Review
UNLABELLED
The purpose of this systematic review is to identify, describe and assess the potential effectiveness of strategies to respond to issues of vaccine hesitancy that have been implemented and evaluated across diverse global contexts.
METHODS
A systematic review of peer reviewed (January 2007-October 2013) and grey literature (up to October 2013) was conducted using a broad search strategy, built to capture multiple dimensions of public trust, confidence and hesitancy concerning vaccines. This search strategy was applied and adapted across several databases and organizational websites. Descriptive analyses were undertaken for 166 (peer reviewed) and 15 (grey literature) evaluation studies. In addition, the quality of evidence relating to a series of PICO (population, intervention, comparison/control, outcomes) questions defined by the SAGE Working Group on Vaccine Hesitancy (WG) was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria; data were analyzed using Review Manager.
RESULTS
Across the literature, few strategies to address vaccine hesitancy were found to have been evaluated for impact on either vaccination uptake and/or changes in knowledge, awareness or attitude (only 14% of peer reviewed and 25% of grey literature). The majority of evaluation studies were based in the Americas and primarily focused on influenza, human papillomavirus (HPV) and childhood vaccines. In low- and middle-income regions, the focus was on diphtheria, tetanus and pertussis, and polio. Across all regions, most interventions were multi-component and the majority of strategies focused on raising knowledge and awareness. Thirteen relevant studies were used for the GRADE assessment that indicated evidence of moderate quality for the use of social mobilization, mass media, communication tool-based training for health-care workers, non-financial incentives and reminder/recall-based interventions. Overall, our results showed that multicomponent and dialogue-based interventions were most effective. However, given the complexity of vaccine hesitancy and the limited evidence available on how it can be addressed, identified strategies should be carefully tailored according to the target population, their reasons for hesitancy, and the specific context.
Topics: Communication; Health Knowledge, Attitudes, Practice; Health Personnel; Humans; Patient Acceptance of Health Care; Patient Compliance; Treatment Refusal; Vaccination; Vaccines; World Health Organization
PubMed: 25896377
DOI: 10.1016/j.vaccine.2015.04.040 -
Journal of Neurology Jan 2021We conducted a systematic review and wide-angled Mendelian randomization (MR) study to examine the association between possible risk factors and multiple sclerosis (MS).
OBJECTIVES
We conducted a systematic review and wide-angled Mendelian randomization (MR) study to examine the association between possible risk factors and multiple sclerosis (MS).
METHODS
We used MR analysis to assess the associations between 65 possible risk factors and MS using data from a genome-wide association study including 14 498 cases and 24 091 controls of European ancestry. For 18 exposures not suitable for MR analysis, we conducted a systematic review to obtain the latest meta-analyses evidence on their associations with MS.
RESULTS
Childhood and adulthood body mass index were positively associated with MS, whereas physical activity and serum 25-hydroxyvitamin D were inversely associated with MS. There was evidence of possible associations of type 2 diabetes, waist circumference, body fat percentage, age of puberty and high-density lipoprotein cholesterol. Data of systematic review showed that exposure to organic solvents, Epstein Barr virus and cytomegalovirus virus infection, and diphtheria and tetanus vaccination were associated with MS risk.
CONCLUSIONS
This study identified several modifiable risk factors for primary prevention of MS that should inform public health policy.
Topics: Adult; Child; Diabetes Mellitus, Type 2; Epstein-Barr Virus Infections; Genome-Wide Association Study; Herpesvirus 4, Human; Humans; Mendelian Randomization Analysis; Multiple Sclerosis; Risk Factors
PubMed: 32728946
DOI: 10.1007/s00415-020-10119-8 -
Vaccine Jun 2021Understanding the safety of vaccines is critical to inform decisions about vaccination. Our objective was to conduct a systematic review of the safety of vaccines... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Understanding the safety of vaccines is critical to inform decisions about vaccination. Our objective was to conduct a systematic review of the safety of vaccines recommended for children, adults, and pregnant women in the United States.
METHODS
We searched the literature in November 2020 to update a 2014 Agency for Healthcare Research and Quality review by integrating newly available data. Studies of vaccines that used a comparator and reported the presence or absence of key adverse events were eligible. Adhering to Evidence-based Practice Center methodology, we assessed the strength of evidence (SoE) for all evidence statements. The systematic review is registered in PROSPERO (CRD42020180089).
RESULTS
Of 56,603 reviewed citations, 338 studies reported in 518 publications met inclusion criteria. For children, SoE was high for no increased risk of autism following measles, mumps, and rubella (MMR) vaccine. SoE was high for increased risk of febrile seizures with MMR. There was no evidence of increased risk of intussusception with rotavirus vaccine at the latest follow-up (moderate SoE), nor of diabetes (high SoE). There was no evidence of increased risk or insufficient evidence for key adverse events for newer vaccines such as 9-valent human papillomavirus and meningococcal B vaccines. For adults, there was no evidence of increased risk (varied SoE) or insufficient evidence for key adverse events for the new adjuvanted inactivated influenza vaccine and recombinant adjuvanted zoster vaccine. We found no evidence of increased risk (varied SoE) for key adverse events among pregnant women following tetanus, diphtheria, and acellular pertussis vaccine, including stillbirth (moderate SoE).
CONCLUSIONS
Across a large body of research we found few associations of vaccines and serious key adverse events; however, rare events are challenging to study. Any adverse events should be weighed against the protective benefits that vaccines provide.
Topics: Adult; Child; Diphtheria; Female; Humans; Infant; Measles; Measles-Mumps-Rubella Vaccine; Mumps; Pregnancy; United States; Vaccination
PubMed: 34049735
DOI: 10.1016/j.vaccine.2021.03.079 -
Vaccine Jan 2019Coverage levels for many recommended adult vaccinations are low. The cost-effectiveness research literature on adult vaccinations has not been synthesized in recent...
BACKGROUND
Coverage levels for many recommended adult vaccinations are low. The cost-effectiveness research literature on adult vaccinations has not been synthesized in recent years, which may contribute to low awareness of the value of adult vaccinations and to their under-utilization. We assessed research literature since 1980 to summarize economic evidence for adult vaccinations included on the adult immunization schedule.
METHODS
We searched PubMed, EMBASE, EconLit, and Cochrane Library from 1980 to 2016 and identified economic evaluation or cost-effectiveness analysis for vaccinations targeting persons aged ≥18 years in the U.S. or Canada. After excluding records based on title and abstract reviews, the remaining publications had a full-text review from two independent reviewers, who extracted economic values that compared vaccination to "no vaccination" scenarios.
RESULTS
The systematic searches yielded 1688 publications. After removing duplicates, off-topic publications, and publications without a "no vaccination" comparison, 78 publications were included in the final analysis (influenza = 25, pneumococcal = 18, human papillomavirus = 9, herpes zoster = 7, tetanus-diphtheria-pertussis = 9, hepatitis B = 9, and multiple vaccines = 1). Among outcomes assessing age-based vaccinations, the percent indicating cost-savings was 56% for influenza, 31% for pneumococcal, and 23% for tetanus-diphtheria-pertussis vaccinations. Among age-based vaccination outcomes reporting $/QALY, the percent of outcomes indicating a cost per QALY of ≤$100,000 was 100% for influenza, 100% for pneumococcal, 69% for human papillomavirus, 71% for herpes zoster, and 50% for tetanus-diphtheria-pertussis vaccinations.
CONCLUSIONS
The majority of published studies report favorable cost-effectiveness profiles for adult vaccinations, which supports efforts to improve the implementation of adult vaccination recommendations.
Topics: Adult; Age Factors; Canada; Cost-Benefit Analysis; Diphtheria; Diphtheria-Tetanus-Pertussis Vaccine; Hepatitis B; Humans; Immunization Schedule; Influenza Vaccines; Influenza, Human; Pneumococcal Vaccines; Pneumonia, Pneumococcal; Tetanus; United States; Vaccination
PubMed: 30527660
DOI: 10.1016/j.vaccine.2018.11.056 -
The Cochrane Database of Systematic... Jan 2020Adolescent vaccination has received increased attention since the Global Vaccine Action Plan's call to extend the benefits of immunisation more equitably beyond... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Adolescent vaccination has received increased attention since the Global Vaccine Action Plan's call to extend the benefits of immunisation more equitably beyond childhood. In recent years, many programmes have been launched to increase the uptake of different vaccines in adolescent populations; however, vaccination coverage among adolescents remains suboptimal. Therefore, understanding and evaluating the various interventions that can be used to improve adolescent vaccination is crucial.
OBJECTIVES
To evaluate the effects of interventions to improve vaccine uptake among adolescents.
SEARCH METHODS
In October 2018, we searched the following databases: CENTRAL, MEDLINE Ovid, Embase Ovid, and eight other databases. In addition, we searched two clinical trials platforms, electronic databases of grey literature, and reference lists of relevant articles. For related systematic reviews, we searched four databases. Furthermore, in May 2019, we performed a citation search of five other websites.
SELECTION CRITERIA
Randomised trials, non-randomised trials, controlled before-after studies, and interrupted time series studies of adolescents (girls or boys aged 10 to 19 years) eligible for World Health Organization-recommended vaccines and their parents or healthcare providers.
DATA COLLECTION AND ANALYSIS
Two review authors independently screened records, reviewed full-text articles to identify potentially eligible studies, extracted data, and assessed risk of bias, resolving discrepancies by consensus. For each included study, we calculated risk ratios (RR) or mean differences (MD) with 95% confidence intervals (CI) where appropriate. We pooled study results using random-effects meta-analyses and assessed the certainty of the evidence using GRADE.
MAIN RESULTS
We included 16 studies (eight individually randomised trials, four cluster randomised trials, three non-randomised trials, and one controlled before-after study). Twelve studies were conducted in the USA, while there was one study each from: Australia, Sweden, Tanzania, and the UK. Ten studies had unclear or high risk of bias. We categorised interventions as recipient-oriented, provider-oriented, or health systems-oriented. The interventions targeted adolescent boys or girls or both (seven studies), parents (four studies), and providers (two studies). Five studies had mixed participants that included adolescents and parents, adolescents and healthcare providers, and parents and healthcare providers. The outcomes included uptake of human papillomavirus (HPV) (11 studies); hepatitis B (three studies); and tetanus-diphtheria-acellular-pertussis (Tdap), meningococcal, HPV, and influenza (three studies) vaccines among adolescents. Health education improves HPV vaccine uptake compared to usual practice (RR 1.43, 95% CI 1.16 to 1.76; I² = 0%; 3 studies, 1054 participants; high-certainty evidence). In addition, one large study provided evidence that a complex multi-component health education intervention probably results in little to no difference in hepatitis B vaccine uptake compared to simplified information leaflets on the vaccine (RR 0.98, 95% CI 0.97 to 0.99; 17,411 participants; moderate-certainty evidence). Financial incentives may improve HPV vaccine uptake compared to usual practice (RR 1.45, 95% CI 1.05 to 1.99; 1 study, 500 participants; low-certainty evidence). However, we are uncertain whether combining health education and financial incentives has an effect on hepatitis B vaccine uptake, compared to usual practice (RR 1.38, 95% CI 0.96 to 2.00; 1 study, 104 participants; very low certainty evidence). Mandatory vaccination probably leads to a large increase in hepatitis B vaccine uptake compared to usual practice (RR 3.92, 95% CI 3.65 to 4.20; 1 study, 6462 participants; moderate-certainty evidence). Provider prompts probably make little or no difference compared to usual practice, on completion of Tdap (OR 1.28, 95% CI 0.59 to 2.80; 2 studies, 3296 participants), meningococcal (OR 1.09, 95% CI 0.67 to 1.79; 2 studies, 3219 participants), HPV (OR 0.99, 95% CI 0.55 to 1.81; 2 studies, 859 participants), and influenza (OR 0.91, 95% CI 0.61 to 1.34; 2 studies, 1439 participants) vaccination schedules (moderate-certainty evidence). Provider education with performance feedback may increase the proportion of adolescents who are offered and accept HPV vaccination by clinicians, compared to usual practice. Compared to adolescents visiting non-participating clinicians (in the usual practice group), the adolescents visiting clinicians in the intervention group were more likely to receive the first dose of HPV during preventive visits (5.7 percentage points increase) and during acute visits (0.7 percentage points for the first and 5.6 percentage points for the second doses of HPV) (227 clinicians and more than 200,000 children; low-certainty evidence). A class-based school vaccination strategy probably leads to slightly higher HPV vaccine uptake than an age-based school vaccination strategy (RR 1.09, 95% CI 1.06 to 1.13; 1 study, 5537 participants; moderate-certainty evidence). A multi-component provider intervention (including an education session, repeated contacts, individualised feedback, and incentives) probably improves uptake of HPV vaccine compared to usual practice (moderate-certainty evidence). A multi-component intervention targeting providers and parents involving social marketing and health education may improve HPV vaccine uptake compared to usual practice (RR 1.41, 95% CI 1.25 to 1.59; 1 study, 25,869 participants; low-certainty evidence).
AUTHORS' CONCLUSIONS
Various strategies have been evaluated to improve adolescent vaccination including health education, financial incentives, mandatory vaccination, and class-based school vaccine delivery. However, most of the evidence is of low to moderate certainty. This implies that while this research provides some indication of the likely effect of these interventions, the likelihood that the effects will be substantially different is high. Therefore, additional research is needed to further enhance adolescent immunisation strategies, especially in low- and middle-income countries where there are limited adolescent vaccination programmes. In addition, it is critical to understand the factors that influence hesitancy, acceptance, and demand for adolescent vaccination in different settings. This is the topic of an ongoing Cochrane qualitative evidence synthesis, which may help to explain why and how some interventions were more effective than others in increasing adolescent HPV vaccination coverage.
Topics: Adolescent; Child; Controlled Before-After Studies; Health Education; Health Personnel; Humans; Parents; Randomized Controlled Trials as Topic; Vaccination
PubMed: 31978259
DOI: 10.1002/14651858.CD011895.pub2 -
Global Epidemiology Dec 2023To identify modifiable risk factors for diphtheria and assess their strengths of association with the disease. (Review)
Review
OBJECTIVE
To identify modifiable risk factors for diphtheria and assess their strengths of association with the disease.
METHODS
This review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. Electronic databases and grey literature were searched from inception until January 2023. Studies had to report on diphtheria cases and estimates of association for at least one potential risk factor or sufficient data to calculate these. The quality of non-ecological studies was assessed using the Newcastle-Ottawa Scale (NOS), while the quality of evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria.
RESULTS
The search yielded 37,705 papers, of which 29 were ultimately included. All the non-ecological studies were of moderate to high quality. Meta-analysis of 20 studies identified three factors increasing the risk of diphtheria: incomplete vaccination (<3 doses) (pooled odds ratio (POR) = 2.2, 95% confidence interval (CI) = 1.4-3.4); contact with a person with skin lesions (POR = 4.8, 95% CI = 2.1-10.9); and low knowledge of diphtheria (POR = 2.4, 95% CI = 1.2-4.7). Contact with a case of diphtheria; sharing a bed or bedroom; sharing utensils, cups, and glasses; infrequent bathing; and low parental education were associated with diphtheria in multiple studies. Evidence for other factors was inconclusive. The quality of evidence was low or very low for all the risk factors.
CONCLUSIONS
Findings from the review suggest that countries seeking to control diphtheria need to strengthen surveillance, improve vaccination coverage, and increase people's knowledge of the disease. Future research should focus on understudied or inconclusive risk factors.
PubMed: 37638375
DOI: 10.1016/j.gloepi.2023.100100 -
Journal of Neurology Jun 2017Vaccinations are often the most effective tool against some disease known to mankind. This study offers a literature review on the role of vaccines regarding the risk of... (Review)
Review
Vaccinations are often the most effective tool against some disease known to mankind. This study offers a literature review on the role of vaccines regarding the risk of developing multiple sclerosis (MS) and MS relapse. The method used in this study is a systematic literature review on the database PubMed. The study found no change in risk of developing multiple sclerosis (MS) after vaccination against hepatitis B virus, human papillomavirus, seasonal influenza, measles-mumps-rubella, variola, tetanus, Bacillus Calmette-Guérin (BCG), polio, or diphtheria. No change in risk of relapse was found for influenza. Further research is needed for the potential therapeutic use of the BCG vaccine in patients in risk of developing MS and for the preventive potential of the tetanus and diphtheria vaccine.
Topics: Animals; Humans; Multiple Sclerosis; Vaccination
PubMed: 27604618
DOI: 10.1007/s00415-016-8263-4 -
European Journal of Paediatric... Jan 2022The evidence relating vaccination to febrile seizures and epilepsy is evaluated with an emphasis on febrile seizures (FS), Dravet syndrome (DS), West syndrome, and other...
INTRODUCTION
The evidence relating vaccination to febrile seizures and epilepsy is evaluated with an emphasis on febrile seizures (FS), Dravet syndrome (DS), West syndrome, and other developmental and epileptic encephalopathies.
METHODS
A systematic literature review using search words vaccination/immunization AND febrile seizures/epilepsy/Dravet/epileptic encephalopathy/developmental encephalopathy was performed. The role of vaccination as the cause/trigger/aggravation factor for FS or epilepsies and preventive measures were analyzed.
RESULTS
From 1428 results, 846 duplicates and 447 irrelevant articles were eliminated; 120 were analyzed.
CONCLUSIONS
There is no evidence that vaccinations cause epilepsy in healthy populations. Vaccinations do not cause epileptic encephalopathies but may be non-specific triggers to seizures in underlying structural or genetic etiologies. The first seizure in DS may be earlier in vaccinated versus non-vaccinated patients, but developmental outcome is similar in both groups. Children with a personal or family history of FS or epilepsy should receive all routine vaccinations. This recommendation includes DS. The known risks of the infectious diseases prevented by immunization are well established. Vaccination should be deferred in case of acute illness. Acellular pertussis DTaP (diphtheria-tetanus-pertussis) is recommended. The combination of certain vaccine types may increase the risk of febrile seizures however the public health benefit of separating immunizations has not been proven. Measles-containing vaccine should be administered at age 12-15 months. Routine prophylactic antipyretics are not indicated, as there is no evidence of decreased FS risk and they can attenuate the antibody response following vaccination. Prophylactic measures (preventive antipyretic medication) are recommended in DS due to the increased risk of prolonged seizures with fever.
Topics: Child; Epilepsies, Myoclonic; Epilepsy; Humans; Infant; Seizures, Febrile; Spasms, Infantile; Vaccination
PubMed: 34922162
DOI: 10.1016/j.ejpn.2021.11.014 -
BMJ Global Health Oct 2023Maternal vaccination is a promising strategy to reduce the burden of vaccine-preventable diseases for mothers and infants. We aimed to provide an up-to-date overview of... (Meta-Analysis)
Meta-Analysis
INTRODUCTION
Maternal vaccination is a promising strategy to reduce the burden of vaccine-preventable diseases for mothers and infants. We aimed to provide an up-to-date overview of the efficacy and safety of all available maternal vaccines.
METHODS
We searched PubMed, Embase, CENTRAL and ClinicalTrials.gov on 1 February 2022, for phase III and IV randomised controlled trials (RCTs) that compared maternal vaccination against any pathogen with placebo or no vaccination. Primary outcomes were laboratory-confirmed or clinically confirmed disease in mothers and infants. Secondary safety outcomes included intrauterine growth restriction, stillbirth, maternal death, preterm birth, congenital malformations and infant death. Random effects meta-analysis were used to calculate pooled risk ratio's (RR). Quality appraisal was performed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE).
RESULTS
Six RCTs on four maternal vaccines, influenza, tetanus, diphtheria and pertussis (Tdap), pneumococcal and respiratory syncytial virus (RSV) were eligible. The overall risk of bias and certainty of evidence varied from low to high. Maternal influenza vaccination significantly reduced the number of laboratory-confirmed influenza cases (RR 0.58, 95% CI 0.42 to 0.79, event rate 57 vs 98, 2 RCTs, n=6003, I=0%), and clinically confirmed influenza cases in mothers (RR 0.88, 95% CI 0.78 to 0.99, event rate 418 vs 472, 2 RCTs, n=6003, I=0%), and laboratory-confirmed influenza in infants (RR 0.66, 95% CI 0.52 to 0.85, event rate 98 vs 148, 2 RCTs, n=5883, I=0%), although this was not significant for clinically confirmed influenza in infants (RR 0.99, 95% CI 0.94 to 1.05, event rate 1371 vs 1378, 2 RCTs, n=5883, I=0%). No efficacy data were available on maternal Tdap vaccination. Maternal pneumococcal vaccination did not reduce laboratory-confirmed and clinically confirmed middle ear disease (RR 0.49, 95% CI 0.24 to 1.02, event rate 9 vs 18, 1 RCT, n=133 and RR 0.88 95% CI 0.69 to 1.12, event rate 42 vs 47, 1 RCT, n=133, respectively), and clinically confirmed lower-respiratory tract infection (LRTI) (RR 1.08, 95% CI 0.82 to 1.43, event rate 18 vs 34, 1 RCT, n=70) in infants. Maternal RSV vaccination did not reduce laboratory-confirmed RSV LRTI in infants (RR 0.75, 95% CI 0.56 to 1.01, event rate 103 vs 71, 1 RCT, n=4527). There was no evidence of a significant effect of any of the maternal vaccines on the reported safety outcomes.
CONCLUSIONS
The few RCTs with low event rates suggest that, depending on the type of maternal vaccine, the vaccine might effectively prevent disease and within its size does not show safety concerns in mothers and infants.
PROSPERO REGISTRATION NUMBER
CRD42021235115.
Topics: Infant, Newborn; Female; Humans; Infant; Influenza, Human; Influenza Vaccines; Mothers; Vaccination; Respiratory Tract Infections; Randomized Controlled Trials as Topic
PubMed: 37899087
DOI: 10.1136/bmjgh-2023-012376