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Vaccine Sep 2018Two types of vaccines are currently licensed for use against pertussis: whole-cell (wP) and acellular pertussis (aP). There is evidence that wP confers more durable... (Comparative Study)
Comparative Study
INTRODUCTION
Two types of vaccines are currently licensed for use against pertussis: whole-cell (wP) and acellular pertussis (aP). There is evidence that wP confers more durable immunity than aP, however wP has been more frequently associated with adverse events following immunisation (AEFI). A comparison of the frequency of AEFI with the first doses of wP and aP has not yet been clearly documented. This must be done in light of recent considerations to move towards a wP prime-aP boost vaccination strategy in low and middle-income countries.
OBJECTIVES
To compare the frequency of AEFI associated with the first dose of the wP and aP vaccines. We also compared the frequency of AEFI associated with subsequent doses of wP.
METHODS
This systematic review was carried out in strict accordance with the published protocol.
RESULTS
High heterogeneity amongst included one-armed studies did not allow for pooling of prevalence estimates. The prevalence estimates of AEFI at first vaccine dose of wP ranged from 0 to 75%, while the prevalence estimates of AEFI at first vaccine dose of aP ranges from 0 to 39%. The prevalence estimates of adverse events following second and third vaccine dose of wP ranged from 0 to 71% and 0 to 61%, respectively. Risk ratios among two-armed studies showed an increased risk of adverse events with first dose of wP compared to aP [local reaction RR 2.73 (2.33, 3.21), injection site pain RR 4.15 (3.24, 5.31), injection site swelling RR 4.38 (2.70, 7.12), fever over 38 °C RR 9.21 (5.39, 15.76), drowsiness RR 1.34 (1.18, 1.52) and vomiting RR 1.28 (0.91, 1.79)].
CONCLUSION
Our results confirm that, when comparing the first dose, wP is more reacotgenic than aP. The proposed wP prime followed by aP boost pertussis vaccine strategy should be approached with caution.
Topics: Child; Child, Preschool; Diphtheria-Tetanus-Pertussis Vaccine; Diphtheria-Tetanus-acellular Pertussis Vaccines; Humans; Immunization, Secondary; Infant; Prevalence; Randomized Controlled Trials as Topic; Vaccines, Combined
PubMed: 30143272
DOI: 10.1016/j.vaccine.2018.08.022 -
BMJ (Clinical Research Ed.) Oct 2016To evaluate the effects on non-specific and all cause mortality, in children under 5, of Bacillus Calmette-Guérin (BCG), diphtheria-tetanus-pertussis (DTP), and... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
To evaluate the effects on non-specific and all cause mortality, in children under 5, of Bacillus Calmette-Guérin (BCG), diphtheria-tetanus-pertussis (DTP), and standard titre measles containing vaccines (MCV); to examine internal validity of the studies; and to examine any modifying effects of sex, age, vaccine sequence, and co-administration of vitamin A.
DESIGN
Systematic review, including assessment of risk of bias, and meta-analyses of similar studies.
STUDY ELIGIBILITY CRITERIA
Clinical trials, cohort studies, and case-control studies of the effects on mortality of BCG, whole cell DTP, and standard titre MCV in children under 5.
DATA SOURCES
Searches of Medline, Embase, Global Index Medicus, and the WHO International Clinical Trials Registry Platform, supplemented by contact with experts in the field. To avoid overlap in children studied across the included articles, findings from non-overlapping birth cohorts were identified.
RESULTS
Results from 34 birth cohorts were identified. Most evidence was from observational studies, with some from short term clinical trials. Most studies reported on all cause (rather than non-specific) mortality. Receipt of BCG vaccine was associated with a reduction in all cause mortality: the average relative risks were 0.70 (95% confidence interval 0.49 to 1.01) from five clinical trials and 0.47 (0.32 to 0.69) from nine observational studies at high risk of bias. Receipt of DTP (almost always with oral polio vaccine) was associated with a possible increase in all cause mortality on average (relative risk 1.38, 0.92 to 2.08) from 10 studies at high risk of bias; this effect seemed stronger in girls than in boys. Receipt of standard titre MCV was associated with a reduction in all cause mortality (relative risks 0.74 (0.51 to 1.07) from four clinical trials and 0.51 (0.42 to 0.63) from 18 observational studies at high risk of bias); this effect seemed stronger in girls than in boys. Seven observational studies, assessed as being at high risk of bias, have compared sequences of vaccines; results of a subset of these suggest that administering DTP with or after MCV may be associated with higher mortality than administering it before MCV.
CONCLUSIONS
Evidence suggests that receipt of BCG and MCV reduce overall mortality by more than would be expected through their effects on the diseases they prevent, and receipt of DTP may be associated with an increase in all cause mortality. Although efforts should be made to ensure that all children are immunised on schedule with BCG, DTP, and MCV, randomised trials are needed to compare the effects of different sequences.
Topics: BCG Vaccine; Child; Child, Preschool; Diphtheria; Diphtheria-Tetanus-Pertussis Vaccine; Evidence-Based Medicine; Female; Humans; Immunization Schedule; Infant; Male; Measles; Measles Vaccine; Mortality; Tetanus; Tuberculosis; United Kingdom; Vaccination; Whooping Cough
PubMed: 27737834
DOI: 10.1136/bmj.i5170 -
Global Health Research and Policy Nov 2022COVID-19 vaccination has been advocated as the most effective way to curb the pandemic. But with its inequitable distribution and slow rollout, especially in low- to... (Review)
Review
BACKGROUND
COVID-19 vaccination has been advocated as the most effective way to curb the pandemic. But with its inequitable distribution and slow rollout, especially in low- to middle- income countries, it will still take a long time before herd immunity is achieved. Alternative measures must therefore be explored to bolster current COVID-19 vaccination efforts. In particular, the Bacille Calmette-Guerin vaccine has been studied extensively as to its proposed conferment of non-specific immunity against different infections, including COVID-19. The aim of this study, therefore, is to evaluate the current evidence on the effectiveness of national BCG vaccination policies in reducing infection and mortality of COVID-19.
METHODS
A systematic review was conducted between April to August 2021 following the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA-P) guidelines. Literature was retrieved from PubMed, Cochrane, HERDIN, Web of Science, EBSCO, and Western Pacific Region Index Medicus (WPRIM). Studies conducted from January 2020 to August 2021 that fell within Level 1A to 2C of the Oxford Center for Evidence-Based Medicine were included in the review. Quality assessment was performed using the appropriate Joanna Briggs Institute critical appraisal tool and a quality assessment checklist for ecological studies adapted from Betran et al. RESULTS: A total of 13 studies were included in this review. Nine studies reported significant association between BCG vaccination policies and COVID-19 outcomes, even when controlling for confounding variables. In addition, among other mandated vaccines, such as pneumococcal, influenza, diphtheria-tetanus-pertussis, and measles, only BCG vaccination showed significant association with decreased COVID-19 adverse outcomes. However, other factors also showed positive association with COVID-19 outcomes, particularly markers of high economic status of countries, higher median age, and greater population densities.
CONCLUSION
The lower incidence and mortality of COVID-19 in countries with mandated BCG vaccination may not solely be attributable to BCG vaccination policies, but there is still some evidence that demonstrates a possible protective effect. Clinical trials must be continued before recommendations of BCG vaccinations are to be used as an alternative or booster vaccine against COVID-19.
Topics: Humans; BCG Vaccine; COVID-19; COVID-19 Vaccines; Policy; Vaccination
PubMed: 36336688
DOI: 10.1186/s41256-022-00275-x -
The Cochrane Database of Systematic... Jul 2015Tetanus is an acute, often fatal, disease caused by an exotoxin produced by Clostridium tetani. It occurs in newborn infants born to mothers who do not have sufficient... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Tetanus is an acute, often fatal, disease caused by an exotoxin produced by Clostridium tetani. It occurs in newborn infants born to mothers who do not have sufficient circulating antibodies to protect the infant passively, by transplacental transfer. Prevention may be possible by the vaccination of pregnant or non-pregnant women, or both, with tetanus toxoid, and the provision of clean delivery services. Tetanus toxoid consists of a formaldehyde-treated toxin that stimulates the production of antitoxin.
OBJECTIVES
To assess the effectiveness of tetanus toxoid, administered to women of reproductive age or pregnant women, to prevent cases of, and deaths from, neonatal tetanus.
SEARCH METHODS
We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 January 2015), CENTRAL (The Cochrane Library 2015, Issue 1), PubMed (1966 to 28 January 2015), EMBASE (1974 to 28 January 2015) and reference lists of retrieved studies.
SELECTION CRITERIA
Randomised or quasi-randomised trials evaluating the effects of tetanus toxoid in pregnant women or women of reproductive age on numbers of neonatal tetanus cases and deaths.
DATA COLLECTION AND ANALYSIS
Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy.
MAIN RESULTS
Two effectiveness trials (9823 infants) and one safety trial (48 mothers) were included. The main outcomes were measured on infants born to a subset of those randomised women who became pregnant during the course of the studies. For our primary outcomes, there was no high-quality evidence according to GRADE assessments.One study (1182 infants) assessed the effectiveness of tetanus toxoid in comparison with influenza vaccine in preventing neonatal tetanus deaths. A single dose did not provide significant protection against neonatal tetanus deaths, (risk ratio (RR) 0.57, 95% confidence interval (CI) 0.26 to 1.24; 494 infants; GRADE: low-quality evidence). However, a two- or three-dose course did provide protection against neonatal deaths, (RR 0.02, 95% CI 0.00 to 0.30; 688 infants; GRADE: moderate-quality evidence). Administration of a two- or three-dose course resulted in significant protection when all causes of death are considered as an outcome (RR 0.31, 95% CI 0.17 to 0.55; 688 infants; GRADE: moderate-quality evidence). No effect was detected on causes of death other than tetanus. Cases of neonatal tetanus after at least one dose of tetanus toxoid were reduced in the tetanus toxoid group, (RR 0.20, 95% CI 0.10 to 0.40; 1182 infants; GRADE: moderate-quality evidence).Another study, involving 8641 children, assessed the effectiveness of tetanus-diphtheria toxoid in comparison with cholera toxoid in preventing neonatal mortality after one or two doses. Neonatal mortality was reduced in the tetanus-diphtheria toxoid group (RR 0.68, 95% CI 0.56 to 0.82). In preventing deaths at four to 14 days, neonatal mortality was reduced again in the tetanus-diphtheria toxoid group (RR 0.38, 95% CI 0.27 to 0.55). The quality of evidence as assessed using GRADE was found to be low.The third small trial assessed that pain at injection site was reported more frequently among pregnant women who received tetanus diphtheria acellular pertussis than placebo (RR 5.68, 95% CI 1.54 to 20.94; GRADE: moderate-quality evidence).
AUTHORS' CONCLUSIONS
Available evidence supports the implementation of immunisation practices on women of reproductive age or pregnant women in communities with similar, or higher, levels of risk of neonatal tetanus, to the two study sites.
Topics: Adult; Cause of Death; Diphtheria-Tetanus Vaccine; Female; Humans; Infant, Newborn; Influenza Vaccines; Pregnancy; Randomized Controlled Trials as Topic; Tetanus; Tetanus Toxoid
PubMed: 26144877
DOI: 10.1002/14651858.CD002959.pub4 -
Frontiers in Immunology 2021Immunization with tetanus-diphtheria-acellular pertussis (Tdap) vaccine in pregnancy is increasingly recommended. We determined the effect of Tdap immunization in... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Immunization with tetanus-diphtheria-acellular pertussis (Tdap) vaccine in pregnancy is increasingly recommended. We determined the effect of Tdap immunization in pregnancy on infants' vaccine responses.
METHODS
Individual-participant data meta-analysis of ten studies (n=1884) investigating infants' antibody response to routine immunizations following Tdap immunization in pregnancy was performed. Geometric mean ratios (GMRs) of antigen-specific immunoglobulin G (IgG) levels were calculated using mixed-effects models. Seroprotection rates were compared using chi-squared tests.
RESULTS
Infants of Tdap-immunized women had significantly lower IgG against pertussis toxin (GMR 0.65; 95%CI 0.57-0.74), filamentous haemagglutinin (FHA) (0.68; 0.53-0.87), pertactin (0.65; 0.58-0.72) and fimbria 2/3 (FIM2/3) (0.41; 0.32-0.52) after primary immunization, compared with infants of unimmunized women. These lower levels persisted after booster immunization for FHA (0.72; 0.61-0.84) and FIM2/3 (0.53; 0.29-0.96). After primary immunization, infants of Tdap-immunized women had lower seroprotection rates against diphtheria (90% [843/973] 98% [566/579]; p<0.001) and invasive pneumococcal disease (IPD) caused by 5 (SPN) serotypes (SPN5, SPN6B, SPN9V, SPN19A, SPN23F), and higher seroprotection rates against type b (short-term and long-term seroprotection rates, 86%[471/547] 76%[188/247] and 62%[337/547] 49%(121/247), respectively, all p=0.001). After booster immunization, seroprotection rates against diphtheria and tetanus were 99% (286/288) and (618/619) in infants of Tdap-immunized women, respectively.
CONCLUSIONS
Infants of Tdap-immunized women in pregnancy had lower IgG levels against pertussis, diphtheria and some SPN serotypes after their immunization compared with infants of unimmunized women. Enhanced surveillance of pertussis, diphtheria and IPD in infants is needed to determine the clinical significance of these findings.
SYSTEMATIC REVIEW REGISTRATION
CRD42017079171.
Topics: Antibodies, Bacterial; Diphtheria; Diphtheria-Tetanus-acellular Pertussis Vaccines; Female; Humans; Immunoglobulin G; Infant; Pregnancy; Tetanus; Vaccination; Whooping Cough
PubMed: 34305922
DOI: 10.3389/fimmu.2021.689394 -
EClinicalMedicine Mar 2024Human Immunodeficiency Virus (HIV)-exposed uninfected (HEU) infants have a higher burden of infectious diseases related morbidity and mortality compared with...
BACKGROUND
Human Immunodeficiency Virus (HIV)-exposed uninfected (HEU) infants have a higher burden of infectious diseases related morbidity and mortality compared with HIV-unexposed uninfected (HUU). Immunization of pregnant women living with HIV (PWLWH) could reduce the severity and burden of infectious diseases for HEU in early infancy.
METHODS
We conducted a systematic review of safety and immunogenicity of vaccines administered to PWLWH and meta-analyses to test the overall effect of immunogenicity comparing pregnant women without HIV (PWWH) to PWLWH. We searched MEDLINE, Embase, Web of Science, Virtual Health Library and Cochrane databases in accordance with PRISMA guidelines for randomized controlled trials and observational studies. Review articles, case series, conference abstracts, and animal studies were excluded. Studies were included from inception to 6th September 2023, with no language restrictions. Random effects meta-analyses were performed for immunogenicity using Review manager (RevMan) analysis software version 5.4.1, Geometric Mean Titer (GMT) values were transformed to obtain the mean and standard deviation within RevMan, the effect size was computed and reported as mean difference with respective 95% confidence intervals. The review was registered with PROSPERO CRD42021289081.
FINDINGS
We included 12 articles, comprising 3744 pregnant women, 1714 were PWLWH given either influenza, pneumococcal or an investigational Group B (GBS) vaccine. Five studies described safety outcomes, and no increase in adverse events was reported in PWLWH compared to PWWH. The GMT increase from baseline to 28-35 weeks post vaccination in HA units ranged from 12.4 (95% CI: 9.84-14.9) to 238.8 (95% CI: 0.35-477.9). Meta-analyses of influenza vaccines showed the pooled geometric mean difference in Hemagglutination Inhibition (HAI) titers post vaccination was 56.01 (95% CI: 45.01-67.01), p < 0.001. The increase was less in PWLWH when compared with PWWH: -141.76 (95% CI: -194.96, -88.55), p < 0.001.
INTERPRETATION
There are limited data on the safety and immunogenicity of vaccines given to PWLWH making policy consideration in this group difficult when new vaccines are introduced. With new vaccines on the horizon, PWLWH need to be included in studies to promote vaccine confidence for this special population.
FUNDING
This work was funded by Medical Research Council Joint Clinical Trials Round 9 [MR/T004983/1].
PubMed: 38333366
DOI: 10.1016/j.eclinm.2024.102448 -
Pathogens and Global Health Mar 2017The decline of immunization rates in countries of origin of migrants and refugees, along with risky conditions during the journey to Europe, may threaten migrants'... (Review)
Review
The decline of immunization rates in countries of origin of migrants and refugees, along with risky conditions during the journey to Europe, may threaten migrants' health. We performed a systematic review of the scientific literature in order to assess the frequency of vaccine preventable diseases, and vaccination coverage among migrants and refugees in Europe. To this end, Medline and Cochrane databases were considered. After the screening and the selection process, 58 papers were included in the review. We focused on the following vaccine-preventable diseases: hepatitis B, measles, rubella, mumps, tetanus, poliomyelitis, pertussis, diphtheria, meningitis, and varicella. The results were presented as a qualitative synthesis. In summary, several studies highlighted that migrants and refugees have lower immunization rates compared to European-born individuals. Firstly, this is due to low vaccination coverage in the country of origin. Then, several problems may limit migrants' access to vaccination in Europe: (i) migrants are used to move around the continent, and many vaccines require multiple doses at regular times; (ii) information on the immunization status of migrants is often lacking; (iii) hosting countries face severe economic crises; (iv) migrants often refuse registration with medical authorities for fear of legal consequences and (v) the lack of coordination among public health authorities of neighboring countries may determine either duplications or lack of vaccine administration. Possible strategies to overcome these problems include tailoring immunization services on the specific needs of the target population, developing strong communication campaigns, developing vaccination registers, and promoting collaboration among public health authorities of European Countries.
Topics: Communicable Disease Control; Communicable Diseases; Europe; Evidence-Based Medicine; Humans; Refugees; Transients and Migrants; Vaccination
PubMed: 28165878
DOI: 10.1080/20477724.2017.1281374 -
The Cochrane Database of Systematic... Sep 2021Atopic diseases are the most common chronic conditions of childhood. The apparent rise in food anaphylaxis in young children over the past three decades is of particular... (Review)
Review
BACKGROUND
Atopic diseases are the most common chronic conditions of childhood. The apparent rise in food anaphylaxis in young children over the past three decades is of particular concern, owing to the lack of proven prevention strategies other than the timely introduction of peanut and egg. Due to reported in vitro differences in the immune response of young infants primed with whole-cell pertussis (wP) versus acellular pertussis (aP) vaccine, we systematically appraised and synthesised evidence on the safety and the potential allergy preventive benefits of wP, to inform recommendation for future practice and research.
OBJECTIVES
To assess the efficacy and safety of wP vaccinations in comparison to aP vaccinations in early infancy for the prevention of atopic diseases in children.
SEARCH METHODS
We searched the Cochrane Central Register of Controlled Trials, Ovid MEDLINE, Embase, and grey literature. The date of the search was 7 September 2020.
SELECTION CRITERIA
We included randomised controlled trials (RCTs) and non-randomised studies of interventions (NRSIs) that reported the occurrence of atopic diseases, and RCTs only to assess safety outcomes. To be included studies had to have at least six months follow-up, and involve children under 18 years old, who received a first dose of either wP (experimental intervention) or aP (comparator) before six months of age.
DATA COLLECTION AND ANALYSIS
Two review authors independently screened studies for eligibility, extracted the data, and assessed risk of bias using standard Cochrane methods. We assessed the certainty of the evidence using GRADE. Our primary outcomes were diagnosis of IgE-mediated food allergy and all-cause serious adverse events (SAEs). Secondary outcomes included: diagnosis of not vaccine-associated anaphylaxis or urticaria, diagnosis of asthma, diagnosis of allergic rhinitis, diagnosis of atopic dermatitis and diagnosis of encephalopathy. Due to paucity of RCTs reporting on the atopic outcomes of interest, we assessed a broader outcome domain (cumulative incidence of atopic disease) as specified in our protocol. We summarised effect estimates as risk ratios (RR) and 95% confidence intervals (CI). Where appropriate, we pooled safety data in meta-analyses using fixed-effect Mantel-Haenszel methods, without zero-cell corrections for dichotomous outcomes.
MAIN RESULTS
We identified four eligible studies reporting on atopic outcomes, representing 7333 children. Based on a single trial, there was uncertain evidence on whether wP vaccines affected the risk of overall atopic disease (RR 0.85, 95% CI 0.62 to 1.17) or asthma only (RR 1.04, 95% CI 0.59 to 1.82; 497 children) by 2.5 years old.Three NRSIs were judged to be at serious or critical risk of bias due to confounding, missing data, or both, and were ineligible for inclusion in a narrative synthesis. We identified 21 eligible studies (137,281 children) that reported the safety outcomes of interest. We judged seven studies to be at high risk of bias and those remaining, at unclear risk. The pooled RR was 0.94 for all-cause SAEs (95% CI 0.78 to 1.15; I = 0%; 15 studies, 38,072 children). For every 1000 children primed with a first dose of wP, 11 had an SAE. The corresponding risk with aP was 12 children (95% CI 9 to 13). The 95% CI around the risk difference ranged from three fewer to two more events per 1000 children, and the certainty of the evidence was judged as moderate (downgraded one level for imprecision). No diagnoses of encephalopathy following vaccination were reported (95% CI around the risk difference - 5 to 12 per 100,000 children; seven primary series studies; 115,271 children). The certainty of the evidence was judged as low, since this is a serious condition, and we could not exclude a clinically meaningful difference.
AUTHORS' CONCLUSIONS
There is very low-certainty evidence that a first dose of wP given early in infancy, compared to a first dose of aP, affects the risk of atopic diseases in children. The incidence of all-cause SAEs in wP and aP vaccinees was low, and no cases of encephalopathy were reported. The certainty of the evidence was judged as moderate for all-cause SAEs, and low for encephalopathy. Future studies should use sensitive and specific endpoints of clinical relevance, and should be conducted in settings with high prevalence of IgE-mediated food allergy. Safety endpoints should prioritise common vaccine reactions, parental acceptability, SAEs and their potential relatedness to the dose administered.
Topics: Adolescent; Bias; Child; Child, Preschool; Eczema; Humans; Hypersensitivity, Immediate; Pertussis Vaccine; Whooping Cough
PubMed: 34693993
DOI: 10.1002/14651858.CD013682.pub2 -
PloS One 2019Maternal pertussis vaccination has been introduced in several countries to prevent pertussis morbidity and mortality in infants too young to be vaccinated. Our review...
BACKGROUND
Maternal pertussis vaccination has been introduced in several countries to prevent pertussis morbidity and mortality in infants too young to be vaccinated. Our review aimed to systematically collect and summarize the available evidence on the effectiveness of interventions used to improve pertussis vaccination uptake in pregnant women.
METHODS
We conducted a systematic search of MEDLINE/PubMed, PMC and CINAHL. Before and after studies and those with a concurrent control group were considered for inclusion. Standardized effect sizes were described as the ratio of the odds to be vaccinated in the intervention group compared with the standard care group and absolute benefit increase (ABI) were calculated.
RESULTS
Six studies were included in the review, of which three were randomized controlled trials (RCTs). Strategies to improve uptake were focused on healthcare providers, pregnant women, or enhancing vaccine access. Healthcare provider interventions included provider reminder, education, feedback and standing orders. Interventions directed at pregnant women focused solely on education. Observational studies showed: (1) the provision of maternal pertussis vaccination by midwives at the place of antenatal care has improved uptake of pertussis vaccine during pregnancy from 20% to 90%; (2) introduction of an automated reminder within the electronic medical record was associated with an improvement in the pertussis immunization rate from 48% to 97%; (3) an increase in prenatal pertussis vaccine uptake from 36% to 61% after strategies to increase provider awareness of recommendations were introduced. In contrast to these findings, interventions in all three RCTs (2 involved education of pregnant women, 1 had multi-component interventions) did not demonstrate improved vaccination uptake.
CONCLUSIONS
Based on the existing research, we recommend incorporating midwife delivered maternal immunization programs at antenatal clinics, use of a provider reminder system to target unvaccinated pregnant women and include maternal pertussis immunization as part of standard antenatal care.
Topics: Female; Humans; Patient Acceptance of Health Care; Pertussis Vaccine; Pregnancy; Randomized Controlled Trials as Topic; Vaccination
PubMed: 30921421
DOI: 10.1371/journal.pone.0214538 -
The Cochrane Database of Systematic... Nov 2014A range of strategies are used to communicate with parents, caregivers and communities regarding child vaccination in order to inform decisions and improve vaccination... (Review)
Review
BACKGROUND
A range of strategies are used to communicate with parents, caregivers and communities regarding child vaccination in order to inform decisions and improve vaccination uptake. These strategies include interventions in which information is aimed at larger groups in the community, for instance at public meetings, through radio or through leaflets. This is one of two reviews on communication interventions for childhood vaccination. The companion review focuses on face-to-face interventions for informing or educating parents.
OBJECTIVES
To assess the effects of interventions aimed at communities to inform and/or educate people about vaccination in children six years and younger.
SEARCH METHODS
We searched CENTRAL, MEDLINE, EMBASE and five other databases up to July 2012. We searched for grey literature in the Grey Literature Report and OpenGrey. We also contacted authors of included studies and experts in the field. There were no language, date or settings restrictions.
SELECTION CRITERIA
Individual or cluster-randomised and quasi-randomised controlled trials, interrupted time series (ITS) and repeated measures studies, and controlled before-and-after (CBA) studies. We included interventions aimed at communities and intended to inform and/or educate about vaccination in children six years and younger, conducted in any setting. We defined interventions aimed at communities as those directed at a geographic area, and/or interventions directed to groups of people who share at least one common social or cultural characteristic. Primary outcomes were: knowledge among participants of vaccines or vaccine-preventable diseases and of vaccine service delivery; child immunisation status; and unintended adverse effects. Secondary outcomes were: participants' attitudes towards vaccination; involvement in decision-making regarding vaccination; confidence in the decision made; and resource use or cost of intervention.
DATA COLLECTION AND ANALYSIS
Two authors independently reviewed the references to identify studies for inclusion. We extracted data and assessed risk of bias in all included studies.
MAIN RESULTS
We included two cluster-randomised trials that compared interventions aimed at communities to routine immunisation practices. In one study from India, families, teachers, children and village leaders were encouraged to attend information meetings where they received information about childhood vaccination and could ask questions. In the second study from Pakistan, people who were considered to be trusted in the community were invited to meetings to discuss vaccine coverage rates in their community and the costs and benefits of childhood vaccination. They were asked to develop local action plans and to share the information they had been given and continue the discussions in their communities.The trials show low certainty evidence that interventions aimed at communities to inform and educate about childhood vaccination may improve knowledge of vaccines or vaccine-preventable diseases among intervention participants (adjusted mean difference 0.121, 95% confidence interval (CI) 0.055 to 0.189). These interventions probably increase the number of children who are vaccinated. The study from India showed that the intervention probably increased the number of children who received vaccinations (risk ratio (RR) 1.67, 95% CI 1.21 to 2.31; moderate certainty evidence). The study from Pakistan showed that there is probably an increase in the uptake of both measles (RR 1.63, 95% CI 1.03 to 2.58) and DPT (diptheria, pertussis and tetanus) (RR 2.17, 95% CI 1.43 to 3.29) vaccines (both moderate certainty evidence), but there may be little or no difference in the number of children who received polio vaccine (RR 1.01, 95% CI 0.97 to 1.05; low certainty evidence). There is also low certainty evidence that these interventions may change attitudes in favour of vaccination among parents with young children (adjusted mean difference 0.054, 95% CI 0.013 to 0.105), but they may make little or no difference to the involvement of mothers in decision-making regarding childhood vaccination (adjusted mean difference 0.043, 95% CI -0.009 to 0.097).The studies did not assess knowledge among participants of vaccine service delivery; participant confidence in the vaccination decision; intervention costs; or any unintended harms as a consequence of the intervention. We did not identify any studies that compared interventions aimed at communities to inform and/or educate with interventions directed to individual parents or caregivers, or studies that compared two interventions aimed at communities to inform and/or educate about childhood vaccination.
AUTHORS' CONCLUSIONS
This review provides limited evidence that interventions aimed at communities to inform and educate about early childhood vaccination may improve attitudes towards vaccination and probably increase vaccination uptake under some circumstances. However, some of these interventions may be resource intensive when implemented on a large scale and further rigorous evaluations are needed. These interventions may achieve most benefit when targeted to areas or groups that have low childhood vaccination rates.'
Topics: Child; Child, Preschool; Health Education; Health Knowledge, Attitudes, Practice; Humans; India; Infant; Information Dissemination; Pakistan; Parents; Randomized Controlled Trials as Topic; Vaccination
PubMed: 25408540
DOI: 10.1002/14651858.CD010232.pub2