Reasons for non-uptake of measles, mumps, and rubella catch up immunisation in a measles epidemic and side effects of the vaccine

Prevalence of pain and fear as barriers to vaccination in children - Systematic review and meta-analysis

BACKGROUND

Injection-related pain and fear are common adverse reactions in children undergoing vaccination and influence vaccine acceptance. Despite the large body of literature on sources of vaccine non-compliance, there is no estimate of the prevalence of pain and fear as contributing factors. The objective was to estimate the prevalence of injection pain or fear of needles as barriers to childhood (i.e., 0-18 years) vaccination.

METHODS

Four databases were searched from inception for relevant English and French articles until August 2021. In addition, the references of recent systematic reviews and all articles included in the review were hand searched. Article screening and data extractions were performed in duplicate. Studies were included if they reported on injection-related pain or fear of needles in children (0-18 years) using a checklist/closed-ended question(s). Results were stratified by respondent (parents or children), type of pediatric population (general or under-vaccinated), and relative importance of barrier (pain or needle fear as primary reason or any reason for under-vaccination). Prevalence rates of pain or needle fear were combined using a random effects model. Quality of included studies was assessed using the Joanna Briggs Institute critical appraisal checklist for prevalence data. Quality across studies was assessed using GRADE.

RESULTS

There were 26 studies with 45 prevalence estimates published between 1995 and 2021. For parent reports (of children) and children self-reported reasons for non-compliance, prevalence rates of pain or needle fear ranged from 5 to 13% in a general population and 8 to 28% in an under-vaccinated population, with a substantial variation in the prevalence estimates. There was no difference between category of respondent or relative importance on pain or needle fear prevalence rate. A regression model demonstrated an overall prevalence rate of pain or needle fear as an obstacle to vaccination of 8% in the general population and 18.3% in the under-vaccinated population. All evidence was very low in quality.

CONCLUSION

This is the first review to systematically quantify the prevalence and therefore, importance, of pain and needle fear as obstacles to vaccination in children around the world. Pain from injection or fear of needles were demonstrated to be sufficiently prevalent as barriers to vaccination in children to warrant attention. Addressing pain and fear has the potential to significantly improve vaccination acceptance.

Reduction in Short-term Outpatient Consultations After a Campaign With Measles Vaccine in Children Aged 9-59 Months: Substudy Within a Cluster-Randomized Trial

BACKGROUND

We assessed a measles vaccination campaign's potential short-term adverse events.

METHODS

In a cluster-randomized trial assessing a measles vaccination campaign's effect on all-cause mortality and hospital admission among children aged 9-59 months in Guinea-Bissau, children received a measles vaccination (intervention) or a health check-up (control). One month to 2 months later, we visited a subgroup of children to ask mothers/guardians about outpatient consultations since enrollment. In log-binomial models, we estimated the relative risk (RR) of nonaccidental outpatient consultations.

RESULTS

Among 8319 children (4437 intervention/3882 control), 652 nonaccidental outpatient consultations occurred (322 intervention/330 control). The measles vaccination campaign tended to reduce nonaccidental outpatient consultations by 16% (RR, 0.84 [95% confidence interval {CI}, .65-1.11]), especially if caused by respiratory symptoms (RR, 0.68 [95% CI, .42-1.11]). The reduction tended to be larger in children who prior to trial enrollment had a pentavalent vaccination (diphtheria, tetanus, pertussis, hepatitis B, and Haemophilus influenzae type b) as the most recent vaccination (RR, 0.61 [95% CI, .42-.89]) than in children who prior to trial enrollment had a routine measles vaccination as the most recent vaccination (RR, 0.93 [95% CI, .68-1.26]) (P = .04 for interaction).

CONCLUSIONS

In the short term, a measles vaccination campaign seems not to increase nonaccidental outpatient consultations but may reduce them.

CLINICAL TRIALS REGISTRATION

NCT03460002.

Research protocol of two concurrent cluster-randomized trials: Real-life Effect of a CAMPaign with Measles Vaccination (RECAMP-MV) and Real-life Effect of a CAMPaign with Oral Polio Vaccination (RECAMP-OPV) on mortality and morbidity among children in rural Guinea-Bissau

BACKGROUND

Measles and oral polio vaccinations may reduce child mortality to an extent that cannot be explained by prevention of measles and polio infections; these vaccines seem to have beneficial non-specific effects. In the last decades, billions of children worldwide have received measles vaccine (MV) and oral polio vaccine (OPV) through campaigns. Meanwhile the under-five child mortality has declined. Past MV and OPV campaigns may have contributed to this decline, even in the absence of measles and polio infections. However, cessation of these campaigns, once their targeted infections are eradicated, may reverse the decline in the under-five child mortality. No randomized trial has assessed the real-life effect of either campaign on child mortality and morbidity. We present the research protocol of two concurrent trials: RECAMP-MV and RECAMP-OPV.

METHODS

Both trials are cluster-randomized trials among children registered in Bandim Health Project's rural health and demographic surveillance system throughout Guinea-Bissau. RECAMP-MV is conducted among children aged 9-59 months and RECAMP-OPV is conducted among children aged 0-8 months. We randomized 222 geographical clusters to intervention or control clusters. In intervention clusters, children are offered MV or OPV (according to age at enrolment) and a health check-up. In control clusters, children are offered only a health check-up. Enrolments began in November 2016 (RECAMP-MV) and March 2017 (RECAMP-OPV). We plan 18,000 enrolments for RECAMP-MV with an average follow-up period of 18 months and 10,000 enrolments for RECAMP-OPV with an average follow-up period of 10 months. Data collection is ongoing. The primary outcome in both trials is non-accidental death or non-accidental first non-fatal hospitalization with overnight stay (composite outcome). Secondary outcomes are: non-accidental death, repeated non-fatal hospitalizations with overnight stay, cause-specific primary outcome, outpatient visit, and illness. We obtained ethical approval from Guinea-Bissau and consultative approval from Denmark.

DISCUSSION

Cluster randomization and minimum risk of loss to follow-up are strengths, and no placebo a limitation. Our trials challenge the understanding that MV and OPV only prevent measles and polio, and that once both infections are eradicated, campaigns with MV and OPV can be phased out without negative implications on child health and survival.

TRIAL REGISTRATION

NCT03460002.

Parent Refusal of Topical Fluoride for Their Children: Clinical Strategies and Future Research Priorities to Improve Evidence-Based Pediatric Dental Practice

A growing number of parents are refusing topical fluoride for their children during preventive dental and medical visits. This nascent clinical and public health problem warrants attention from dental professionals and the scientific community. Clinical and community-based strategies are available to improve fluoride-related communications with parents and the public. In terms of future research priorities, there is a need to develop screening tools to identify parents who are likely to refuse topical fluoride and diagnostic instruments to uncover the reasons for topical fluoride refusal. This knowledge will lead to evidence-based strategies that can be widely disseminated into clinical practice.

The impacts of simultaneous disease intervention decisions on epidemic outcomes

Mathematical models of the interplay between disease dynamics and human behavioural dynamics can improve our understanding of how diseases spread when individuals adapt their behaviour in response to an epidemic. Accounting for behavioural mechanisms that determine uptake of infectious disease interventions such as vaccination and non-pharmaceutical interventions (NPIs) can significantly alter predicted health outcomes in a population. However, most previous approaches that model interactions between human behaviour and disease dynamics have modelled behaviour of these two interventions separately. Here, we develop and analyze an agent based network model to gain insights into how behaviour toward both interventions interact adaptively with disease dynamics (and therefore, indirectly, with one another) during the course of a single epidemic where an SIRV infection spreads through a contact network. In the model, individuals decide to become vaccinated and/or practice NPIs based on perceived infection prevalence (locally or globally) and on what other individuals in the network are doing. We find that introducing adaptive NPI behaviour lowers vaccine uptake on account of behavioural feedbacks, and also decreases epidemic final size. When transmission rates are low, NPIs alone are as effective in reducing epidemic final size as NPIs and vaccination combined. Also, NPIs can compensate for delays in vaccine availability by hindering early disease spread, decreasing epidemic size significantly compared to the case where NPI behaviour does not adapt to mitigate early surges in infection prevalence. We also find that including adaptive NPI behaviour strongly mitigates the vaccine behavioural feedbacks that would otherwise result in higher vaccine uptake at lower vaccine efficacy as predicted by most previous models, and the same feedbacks cause epidemic final size to remain approximately constant across a broad range of values for vaccine efficacy. Finally, when individuals use local information about others' behaviour and infection prevalence, instead of population-level information, infection is controlled more efficiently through ring vaccination, and this is reflected in the time evolution of pair correlations on the network. This model shows that accounting for both adaptive NPI behaviour and adaptive vaccinating behaviour regarding social effects and infection prevalence can result in qualitatively different predictions than if only one type of adaptive behaviour is modelled.

Arguments and sources on Italian online forums on childhood vaccinations: Results of a content analysis

BACKGROUND

Despite being committed to the immunization agenda set by the WHO, Italy is currently experiencing decreasing vaccination rates and increasing incidence of vaccine-preventable diseases. Our aim is to analyze Italian online debates on pediatric immunizations through a content analytic approach in order to quantitatively evaluate and summarize users' arguments and information sources.

METHODS

Threads were extracted from 3 Italian forums. Threads had to include the keyword Vaccin* in the title, focus on childhood vaccination, and include at least 10 posts. They had to have been started between 2008 and June 2014. High inter-coder reliability was achieved. Exploratory analysis using k-means clustering was performed to identify users' posting patterns for arguments about vaccines and sources.

RESULTS

The analysis included 6544 posts mentioning 6223 arguments about pediatric vaccinations and citing 4067 sources. The analysis of argument posting patterns included users who published a sufficient number of posts; they generated 85% of all arguments on the forum. Dominating patterns of three groups were identified: (1) an anti-vaccination group (n=280) posted arguments against vaccinations, (2) a general pro-vaccination group (n=222) posted substantially diverse arguments supporting vaccination and (3) a safety-focused pro-vaccination group (n=158) mainly forwarded arguments that questioned the negative side effects of vaccination. The anti-vaccination group was shown to be more active than the others. They use multiple sources, own experience and media as their cited sources of information. Medical professionals were among the cited sources of all three groups, suggesting that vaccination-adverse professionals are gaining attention.

CONCLUSIONS

Knowing which information is shared online on the topic of pediatric vaccinations could shed light on why immunization rates have been decreasing and what strategies would be best suited to address parental concerns. This suggests there is a high need for developing automated approaches to detect misleading or false information on the Internet.

Addressing issues of vaccination literacy and psychological empowerment in the measles-mumps-rubella (MMR) vaccination decision-making: a qualitative study

Background

Whether or not to vaccinate one’s child is one of the first health-related decisions parents have to make after their child’s birth. For the past 20 years, the share of parents choosing not to immunize their children has increased in many countries, for various reasons. Among these, rumors affirming that vaccinations contain dangerous chemicals or might trigger severe chronic diseases have negatively affected parental attitudes towards pediatric immunizations, particularly the vaccination against measles, mumps and rubella (MMR), raising a number of public health concerns. The primary aim of this qualitative study is to understand what drives parents’ decision, giving special attention to vaccination literacy and psychological empowerment in such a context.

Methods

Twenty individual semi-structured interviews were conducted in the Canton of Ticino (Switzerland) between January and June 2014. Participants were either mothers or fathers of children less than 1 year old living in Switzerland. An inductive thematic analysis was performed to identify the main themes with regard to vaccination literacy and psychological empowerment in the MMR vaccination decision-making.

Results

Parents’ reports yielded four main themes: (a) the paradox of the free choice, referring to the misinterpretation of current vaccination policies; (b) giving up the power, pointing at the outcomes of a low perceived competence; (c) a far-reaching decision, reflecting the importance attributed to the MMR choice and the different levels of impact the decision can have; (d) the demand for shared-decision making, referring to the parental needs in relation to the child’s healthcare provider.

Conclusion

Understanding what drives parents’ management of their children’s immunization schedule in terms of vaccination literacy and psychological empowerment can help health professionals to communicate more effectively with parents in order to facilitate an informed decision, and stakeholders to design tailored health education programs and materials. This can ultimately help increase the coverage of the MMR vaccination.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-2200-9) contains supplementary material, which is available to authorized users.

A belief-based model for characterizing the spread of awareness and its impacts on individuals' vaccination decisions

During an epidemic, individuals' decisions on whether or not to take vaccine may affect the dynamics of disease spread and, therefore, the effectiveness of disease control. Empirical studies have shown that such decisions can be subjected to individuals' awareness about disease and vaccine, such as their perceived disease severity and vaccine safety. The aim of this paper is to gain a better understanding of individuals' vaccination behaviour by modelling the spread of awareness in a group of socially connected individuals and examining the associated impacts on their vaccination decision-making. In our model, we examine whether or not individuals will get vaccinated as well as when they would. In doing so, we consider three possible decisions from an individual, i.e., to accept, to reject, and yet to decide, and further associate them with a set of belief values. Next, we extend the Dempster-Shafer theory to characterize individuals' belief value updates and their decision-making, having incorporated the awareness obtained from their connected neighbours. Furthermore, we examine two factors that will affect individuals' vaccination decisions: (i) reporting rates of disease- and vaccine-related events, and (ii) fading coefficient of awareness spread. By doing so, we can assess the impacts of awareness spread by evaluating the vaccination dynamics in terms of the number of vaccinated individuals. The results have demonstrated that the former influences the ratio of vaccinated individuals, whereas the latter affects the time when individuals decide to take vaccine.

Risk factors for transmission of measles during an outbreak: matched case-control study

BACKGROUND

In 2012, an outbreak of measles occurred in Merseyside, UK with 359 confirmed cases by 30 June. Numerous cases reported visits to healthcare and social settings.

AIM

To identify risk factors associated with measles transmission during the outbreak.

METHODS

In April 2012, a retrospective matched case-control study was conducted. Fifty-five confirmed cases and 55 community controls, matched 1:1 for age and geography, were selected at random. Data on exposures in the two weeks before illness, including attendance at a healthcare setting, were collected via telephone interview. Univariate and multi-variate analyses were conducted and odds ratios were calculated.

FINDINGS

Forty-two cases and 42 matched controls were contacted successfully. Univariate exact conditional logistic regression analysis identified that cases were more likely to have attended an emergency department, been admitted to hospital and be incompletely vaccinated (for age). Multi-variate analysis found three factors to be independently associated with measles infection: incomplete/partial vaccination for age [adjusted odds ratio (aOR) 22.1, 95% confidence interval (CI) 3.8-∞, P < 0.001], under age for routine vaccination (aOR 20.4, 95% CI 2.0-∞, P = 0.009) and hospital admission (aOR 20.2, 95% CI 1.4-∞, P = 0.025).

CONCLUSIONS

Incomplete/partial vaccination, under age for routine vaccination and hospital admission were associated with measles infection. These findings highlight the importance of timely vaccination of eligible individuals, early diagnosis, timely isolation of cases, and implementation of strict infection control measures.

School-based vaccination: a systematic review of process evaluations

OBJECTIVE

School-based vaccination is becoming a more widely used method of vaccine delivery. However, evaluations of school-based vaccination program implementation have not been systematically reviewed. This paper describes the results of a systematic review of the literature on process (or implementation) evaluations of school-based vaccination delivery.

METHODS

Search terms: "school based vaccination" OR (("schools" OR "school") AND ("immunisation" OR "immunization" OR "vaccination")).

LIMITS

Humans; English language; Age: 6-18 (school-age children and adolescents); No editorials; No letters. Databases: PUBMED; Embase.com; Cochrane Database of Systematic Reviews; Cinahl; Web of Science; PsycINFO. Inclusions: Articles must have originated from an advanced economic 'developed' country, be peer-reviewed, available in English, randomised or non-randomised controlled design, published from 1970 to August 2010 and focused on vaccinations provided in the school setting and during school time which reported one or more outcomes.

EXCLUSIONS

qualitative or descriptive papers without any evaluation component; papers that only reported on impact evaluation (i.e. number of students vaccinated); and those published before 1970.

RESULTS

A total of 14 articles were identified as including some element of a process evaluation of a school-based vaccination program. Nurses, parents, teachers, and adolescents were involved in measures of procedural factors related to school-based vaccination implementation. Outcomes included return rates of consent forms; knowledge about the specific vaccine offered; attitudes toward vaccination and school-based vaccination; reasons for non-vaccination; resources, support, and procedures related to implementation; and environmental factors within the school that may impact vaccination success. Vaccination coverage was also reported in the majority of papers.

CONCLUSIONS

Many studies reported on the importance of ensuring all stakeholders (school nurses, parents, teachers, and adolescents) receive appropriate information and are involved in the vaccination program and implementation processes. Specific consent form dissemination procedures have demonstrated higher return rates. Further controlled studies are needed to determine the best practice approach to implementing these programs is a variety of contexts.

Measles transmission from an anthroposophic community to the general population, Germany 2008

BACKGROUND

In Germany, measles vaccination coverage with two doses is not yet sufficient to prevent regional outbreaks. Among the 16 German federal states, vaccination coverage was lowest in Bavaria with 85% in 2008. From March to mid-April 2008, four neighbouring Bavarian counties reported 55 measles-cases mostly linked to an ongoing measles outbreak in an anthroposophic school in Austria. We investigated this outbreak to guide future public health action.

METHODS

We applied the German national case-definition for measles and collected data using the national surveillance system and a questionnaire. Measles cases with disease onset a maximum of 18 days apart and spatial contact (e.g. same household, same school) were summed up in clusters. Two different interventions, which were implemented in schools and kindergartens in Bavaria, were compared by their impact on the size and duration of measles clusters. Susceptible persons were excluded from schools or kindergartens either with the first (intervention A) or second (intervention B) measles case occurring in the respective institution.

RESULTS

Among the 217 Bavarian measles cases identified from March-July 2008, 28 (13%) cases were attendees of the anthroposophic school in Austria. In total, vaccination status was known in 161 (74%) cases and 156 (97%) of them were not vaccinated. The main factor for non-vaccination was "fear of vaccine-related adverse events" (33%). Twenty-nine (18%) of 161 cases suffered complications. Exclusively genotype D5 was detected. Overall, 184 cases could be epidemiologically grouped into 59 clusters. Of those, 41 clusters could be linked to households and 13 to schools or kindergartens. The effect of intervention A and B was analysed in 10 school or kindergarten clusters. Depending on the respective intervention A or B, the median number of cases per cluster was 3 versus 13 (p = 0.05), and the median duration of a cluster was 3 versus 26 days (p = 0.13).

CONCLUSIONS

Introduction of measles virus into a pocket of susceptible persons (e.g. vaccination opponents or sceptics) may lead to large outbreaks in the general population, if the general population's vaccination coverage is below the WHO recommended level. Education on the safety of measles vaccine needs to be strengthened to increase measles vaccination coverage. Early intervention may limit spread in schools or kindergartens. Suspected measles has to be reported immediately to the local health authorities in order to allow intervention as early as possible.

Attitudinal and demographic predictors of measles-mumps-rubella vaccine (MMR) uptake during the UK catch-up campaign 2008-09: cross-sectional survey

Background and Objective

Continued suboptimal measles-mumps-rubella (MMR) vaccine uptake has re-established measles epidemic risk, prompting a UK catch-up campaign in 2008–09 for children who missed MMR doses at scheduled age. Predictors of vaccine uptake during catch-ups are poorly understood, however evidence from routine schedule uptake suggests demographics and attitudes may be central. This work explored this hypothesis using a robust evidence-based measure.

Design

Cross-sectional self-administered questionnaire with objective behavioural outcome.

Setting and Participants

365 UK parents, whose children were aged 5–18 years and had received <2 MMR doses before the 2008–09 UK catch-up started.

Main Outcome Measures

Parents' attitudes and demographics, parent-reported receipt of invitation to receive catch-up MMR dose(s), and catch-up MMR uptake according to child's medical record (receipt of MMR doses during year 1 of the catch-up).

Results

Perceived social desirability/benefit of MMR uptake (OR = 1.76, 95% CI = 1.09–2.87) and younger child age (OR = 0.78, 95% CI = 0.68–0.89) were the only independent predictors of catch-up MMR uptake in the sample overall. Uptake predictors differed by whether the child had received 0 MMR doses or 1 MMR dose before the catch-up. Receipt of catch-up invitation predicted uptake only in the 0 dose group (OR = 3.45, 95% CI = 1.18–10.05), whilst perceived social desirability/benefit of MMR uptake predicted uptake only in the 1 dose group (OR = 9.61, 95% CI = 2.57–35.97). Attitudes and demographics explained only 28% of MMR uptake in the 0 dose group compared with 61% in the 1 dose group.

Conclusions

Catch-up MMR invitations may effectively move children from 0 to 1 MMR doses (unimmunised to partially immunised), whilst attitudinal interventions highlighting social benefits of MMR may effectively move children from 1 to 2 MMR doses (partially to fully immunised). Older children may be best targeted through school-based programmes. A formal evaluation element should be incorporated into future catch-up campaigns to inform their continuing improvement.

The impact of vaccine side effects on the natural history of immunization programmes: an imitation-game approach

When the incidence and prevalence of most common vaccine preventable childhood infectious diseases are constantly low, as is the case in many industrialized countries, the incidence of vaccine-associated side effects might become a key determinant in vaccine demand. We study an SIR transmission model with dynamic vaccine demand based on an imitation mechanism where the perceived risk of vaccination is modelled as a function of the incidence of vaccine side effects. The model shows some important differences compared to previous game dynamic models of vaccination, and allows noteworthy inferences as regards both the past and future lifetime of vaccination programmes. In particular it is suggested that a huge disproportion between the perceived risk of disease and vaccination is necessary in order to achieve high coverages. This disproportion is further increased in highly industrialised countries. Such considerations represent serious challenges for future vaccination programmes.

A game dynamic model for delayer strategies in vaccinating behaviour for pediatric infectious diseases

Several studies have found that some parents delay the age at which their children receive pediatric vaccines due to perception of higher vaccine risk at the recommended age of vaccination. This has been particularly apparently during the Measles-Mumps-Rubella scare in the United Kingdom. Under a voluntary vaccination policy, vaccine coverage in certain age groups is a potentially complex interplay between vaccinating behaviour, disease dynamics, and age-specific risk factors. Here, we construct an age-structured game dynamic model, where individuals decide whether to vaccinate according to imitation dynamics depending on age-dependent disease prevalence and perceived risk of vaccination. Individuals may be timely vaccinators, delayers, or non-vaccinators. The model exhibits multiple equilibria and a broad range of possible dynamics. For certain parameter regimes, the proportion of timely vaccinators and delayers oscillate in an anti-phase fashion in response to oscillations in infection prevalence. Under an exogenous change to the perceived risk of vaccination as might occur during a vaccine scare, the model can also capture an increase in delayer strategists similar in magnitude to that observed during the Measles-Mumps-Rubella vaccine scare in the United Kingdom. Our model also shows that number of delayers steadily increases with increasing severity of the scare, whereas it saturates to specific value with increases in duration of the scare. Finally, by comparing the model dynamics with and without the option of a delayer strategy, we show that adding a third delayer strategy can have a stabilizing effect on model dynamics. In an era where individual choice--rather than accessibility--is becoming an increasingly important determinant of vaccine uptake, more infectious disease models may need to use game theory or related techniques to determine vaccine uptake.

Should access to fertility treatment be determined by female body mass index?

Resource allocation towards fertility treatment has been extensively debated in countries where fertility treatment is publicly-funded. Medical, social and ethical aspects have been evaluated prior to allocation of resources. Analysis of cost-effectiveness, risks and benefits and poor success rates have led to calls of restricting fertility treatment to obese women. In this debate article, we critically appraise the evidence underlying this issue and highlight the problems with such a policy. Poor success rate of treatment is unsubstantiated as there is insufficient evidence to link high body mass index (BMI) to reduction in live birth. Obstetric complications have a linear relationship with BMI but are significantly influenced by maternal age. The same is true for miscarriage rates which are influenced by the confounding factors of polycystic ovary syndrome and age. Studies have shown that the direct costs per live birth are no greater for overweight and obese women. With changing demographics over half the reproductive-age population is overweight or obese. Restricting fertility treatment on the grounds of BMI would cause stigmatization and lead to inequity, feelings of injustice and social tension as affluent women manage to bypass these draconian restrictions. Time lost and poor success of conventional weight loss strategies would jeopardize the chances of conception for many women.

Inadequate pain management during routine childhood immunizations: the nerve of it

BACKGROUND

Immunization is regarded as one of the most significant medical achievements of all time. Recently, increasing attention has been paid to the pain resulting from routine childhood immunizations.

OBJECTIVE

This narrative review summarizes existing knowledge about: (1) the epidemiology of childhood immunization pain; (2) the pain experience of children undergoing immunization; (3) current analgesic practices; (4) barriers to practicing pain management in children; and (5) recommendations for improvements in pain management during immunization.

METHODS

We conducted a search of MEDLINE, PsycINFO, EMBASE, CINAHL, and the Cochrane Central Register of Controlled Trials for primary research and review articles published from inception of the databases through October 2008. Key search terms included immunization, pain, child/infant, vaccine, and intervention. Additional studies were identified through searches of the reference lists in the retrieved articles. No language restrictions were imposed regarding the type of article (eg, full article, abstract) or language.

RESULTS

Vaccine injections are the most common iatrogenic procedure performed in childhood and a major source of distress for children (of all ages), their parents, and the participating health care professionals, as well as a direct cause of vaccine nonadherence. In addition, lack of adequate pain management during immunization exposes children to unnecessary suffering and the potential for long-term consequences, such as fear of needles. Numerous pain management strategies are available to reduce vaccine injection pain, including: (1) physical interventions and injection techniques; (2) psychological interventions; and (3) phar-macologic and combined interventions. However, adoption of pain-relieving techniques into clinical practice has been suboptimal. The underutilization of pain management strategies can be attributed to a lack of knowledge about pain and effective pain prevention strategies, and the persistence of attitudes about pain that interfere with optimal clinical practices. Current analgesic practices could be improved substantially if all stakeholders involved in immunization (eg, policy makers, practitioners, consumers) participate in efforts to reduce pain. Treating pain during childhood immunization has the potential to reduce distress during the procedure and greatly improve satisfaction with the immunization experience through more positive experiences for children and their families. Other potential benefits include improved adherence to immunization schedules and reduced sequelae of untreated pain.

CONCLUSION

Immunization is a global health priority. Medical care can be improved if pain management becomes a routine aspect of the delivery of vaccine injections.

Optimal vaccination choice, vaccination games, and rational exemption: an appraisal

A threat for vaccination policies might be the onset of "rational" exemption, i.e. the family's decision not to vaccinate children after a seemingly rational comparison between the perceived risk of infection and the perceived risk of vaccine side effects. We study the implications of rational exemption by models of vaccination choice. By a simple model of individual choice we first prove the "elimination impossible" result in presence of informed families, i.e. aware of herd immunity, and suggest that limited information might explain patterns of universal vaccination. Next, we investigate vaccination choice in a game-theoretic framework for communities stratified into two groups, "pro" and "anti" vaccinators, having widely different perceived costs of infection and of vaccine side effects. We show that under informed families neither a Nash nor a Stackelberg behaviour (characterized, respectively, by players acting simultaneously and by an asymmetric situation with a "leader" and a "follower) allow elimination, unless "pro-vaccinators" assign no costs to vaccine side effects. Elimination turns out to be possible when cooperation is encouraged by a social planner, provided, however, he incorporates in the "social loss function" the preferences of anti-vaccinators only. This allows an interpretation of the current Italian vaccination policy.

Routine vaccination against pertussis and the risk of childhood asthma: a population-based cohort study

BACKGROUND

In industrialized countries vaccination coverage remains suboptimal, partly because of perception of an increased risk of asthma. Epidemiologic studies of the association between childhood vaccinations and asthma have provided conflicting results, possibly for methodologic reasons such as unreliable vaccination data, biased reporting, and reverse causation. A recent review stressed the need for additional, adequately controlled large-scale studies.

OBJECTIVE

Our goal was to determine if routine childhood vaccination against pertussis was associated with subsequent development of childhood wheezing disorders and asthma in a large population-based cohort study.

METHODS

In 6811 children from the general population born between 1993 and 1997 in Leicestershire, United Kingdom, respiratory symptom data from repeated questionnaire surveys up to 2003 were linked to independently collected vaccination data from the National Health Service database. We compared incident wheeze and asthma between children of different vaccination status (complete, partial, and no vaccination against pertussis) by computing hazard ratios. Analyses were based on 6048 children, 23 201 person-years of follow-up, and 2426 cases of new-onset wheeze.

RESULTS

There was no evidence for an increased risk of wheeze or asthma in children vaccinated against pertussis compared with nonvaccinated children. Adjusted hazard ratios comparing fully and partially vaccinated with nonvaccinated children were close to one for both incident wheeze and asthma.

CONCLUSION

This study provides no evidence of an association between vaccination against pertussis in infancy and an increased risk of later wheeze or asthma and does not support claims that vaccination against pertussis might significantly increase the risk of childhood asthma.

Social contact networks and disease eradicability under voluntary vaccination

Certain theories suggest that it should be difficult or impossible to eradicate a vaccine-preventable disease under voluntary vaccination: Herd immunity implies that the individual incentive to vaccinate disappears at high coverage levels. Historically, there have been examples of declining coverage for vaccines, such as MMR vaccine and whole-cell pertussis vaccine, that are consistent with this theory. On the other hand, smallpox was globally eradicated by 1980 despite voluntary vaccination policies in many jurisdictions. Previous modeling studies of the interplay between disease dynamics and individual vaccinating behavior have assumed that infection is transmitted in a homogeneously mixing population. By comparison, here we simulate transmission of a vaccine-preventable SEIR infection through a random, static contact network. Individuals choose whether to vaccinate based on infection risks from neighbors, and based on vaccine risks. When neighborhood size is small, rational vaccinating behavior results in rapid containment of the infection through voluntary ring vaccination. As neighborhood size increases (while the average force of infection is held constant), a threshold is reached beyond which the infection can break through partially vaccinated rings, percolating through the whole population and resulting in considerable epidemic final sizes and a large number vaccinated. The former outcome represents convergence between individually and socially optimal outcomes, whereas the latter represents their divergence, as observed in most models of individual vaccinating behavior that assume homogeneous mixing. Similar effects are observed in an extended model using smallpox-specific natural history and transmissibility assumptions. This work illustrates the significant qualitative differences between behavior-infection dynamics in discrete contact-structured populations versus continuous unstructured populations. This work also shows how disease eradicability in populations where voluntary vaccination is the primary control mechanism may depend partly on whether the disease is transmissible only to a few close social contacts or to a larger subset of the population.

Dynamics of Vaccination Strategies via Projected Dynamical Systems

Previous game theoretical analyses of vaccinating behaviour have underscored the strategic interaction between individuals attempting to maximise their health states, in situations where an individual's health state depends upon the vaccination decisions of others due to the presence of herd immunity. Here, we extend such analyses by applying the theories of variational inequalities (VI) and projected dynamical systems (PDS) to vaccination games. A PDS provides a dynamics that gives the conditions for existence, uniqueness and stability properties of Nash equilibria. In this paper, it is used to analyse the dynamics of vaccinating behaviour in a population consisting of distinct social groups, where each group has different perceptions of vaccine and disease risks. In particular, we study populations with two groups, where the size of one group is strictly larger than the size of the other group (a majority/minority population). We find that a population with a vaccine-inclined majority group and a vaccine-averse minority group exhibits higher average vaccine coverage than the corresponding homogeneous population, when the vaccine is perceived as being risky relative to the disease. Our model also reproduces a feature of real populations: In certain parameter regimes, it is possible to have a majority group adopting high vaccination rates and simultaneously a vaccine-averse minority group adopting low vaccination rates. Moreover, we find that minority groups will tend to exhibit more extreme changes in vaccinating behaviour for a given change in risk perception, in comparison to majority groups. These results emphasise the important role played by social heterogeneity in vaccination behaviour, while also highlighting the valuable role that can be played by PDS and VI in mathematical epidemiology.

Does qualitative synthesis of anecdotal evidence with that from scientific research help in understanding public health issues: a review of low MMR uptake

STUDY OBJECTIVE

To explore the professional and parental factors underlying low MMR uptake by qualitative synthesis of evidence from technical and non-technical anecdotal literature.

METHODS

An intensive investigation of literature covering research, press, online, E groups and grey literature was carried out using devised search strategies. Key themes were identified from both the research and anecdotal evidence, which were merged to form common themes.

RESULTS

The review of technical literature identified media scare and inadequate information from health professionals as the main reasons for non-uptake of MMR. The non-technical anecdotal evidence showed that professionals' belief in parental right to choose, target payments and fear of autism were the major factors.

CONCLUSIONS

Anecdotal evidence may contribute to evidence-based public health practice, especially in widely debated public health issues.

Imitation dynamics predict vaccinating behaviour

There exists an interplay between vaccine coverage, disease prevalence and the vaccinating behaviour of individuals. Moreover, because of herd immunity, there is also a strategic interaction between individuals when they are deciding whether or not to vaccinate, because the probability that an individual becomes infected depends upon how many other individuals are vaccinated. To understand this potentially complex interplay, a game dynamic model is developed in which individuals adopt strategies according to an imitation dynamic (a learning process), and base vaccination decisions on disease prevalence and perceived risks of vaccines and disease. The model predicts that oscillations in vaccine uptake are more likely in populations where individuals imitate others more readily or where vaccinating behaviour is more sensitive to changes in disease prevalence. Oscillations are also more likely when the perceived risk of vaccines is high. The model reproduces salient features of the time evolution of vaccine uptake and disease prevalence during the whole-cell pertussis vaccine scare in England and Wales during the 1970s. This suggests that using game theoretical models to predict, and even manage, the population dynamics of vaccinating behaviour may be feasible.

Open randomized trial comparing the immunogenicity and safety of a new measles-mumps-rubella vaccine and a licensed vaccine in 12- to 24-month-old children

BACKGROUND

A trivalent measles-mumps-rubella (MMR) vaccine (MMR Berna) has been developed with a new mumps component, BBM-18, to replace a previously licensed MMR vaccine containing the Rubini mumps strain. Previous studies showed Rubini to confer insufficient long term protection against mumps infection. This study compared the immunogenicity and safety of MMR Berna, which is produced entirely in human diploid cells, with those of the licensed vaccine M-M-RVax (Merck & Co.).

METHODS

We vaccinated 467 subjects, 12-24 months of age, in an open, randomized (1:1), phase II, multicenter study. Antibody titers were determined for each vaccine component with a plaque neutralization test (PNT) and a commercial enzyme-linked immunosorbent assay. Solicited local and systemic reactions were recorded in subject diaries for 6 weeks after vaccination.

RESULTS

Seroconversion rates 6 to 8 weeks after vaccination for measles and rubella were statistically comparable for the 2 vaccines. However, mumps seroconversion rates were highly assay dependent, with significant differences being measured with the enzyme-linked immunosorbent assay (Berna, 77.4%; Merck, 91.3%; P < 0.001) but not the PNT (Berna, 84.8%; Merck, 87.6%; P = 0.42). The overall rate of systemic reactions was lower in the MMR Berna group (36.8% versus 45.9%; P < 0.05), including a significantly lower rate of fever of >38 degrees C (37.2% versus 51.8%; P < 0.01).

CONCLUSIONS

MMR Berna was statistically noninferior to M-M-RVax with respect to seroconversion rates, and the BBM-18 strain elicited a level of functional antimumps antibodies comparable to the Jeryl Lynn strain, as measured with the PNT. Overall, MMR Berna was better tolerated than the comparison vaccine, particularly with respect to the frequency of fever.

Attitudes and risk perception of parents of different ethnic backgrounds regarding meningococcal C vaccination

The aim of the present study is to assess the attitudes of parents toward vaccination as well as their risk perception of disease and vaccination. We interviewed 1763 parents of different ethnic groups (among others, Dutch, Turkish, Moroccan, and Surinamese parents). Results show that there were large differences in knowledge about disease and risk perception of disease and vaccination among parents of different ethnic backgrounds. Generally, people largely overestimated the risk of contracting the disease and the risk of dying after contracting the disease. Dutch parents were best informed, least worried, had the most critical attitude toward the campaign, and the lowest vaccination level compared to other parents. The differences in knowledge about vaccination and the more critical attitude of Dutch parents emphasize the need to take more into account parents' perspectives when designing information leaflets or other information media.

Vaccination and the theory of games

Voluntary vaccination policies for childhood diseases present parents with a subtle challenge: if a sufficient proportion of the population is already immune, either naturally or by vaccination, then even the slightest risk associated with vaccination will outweigh the risk from infection. As a result, individual self-interest might preclude complete eradication of a vaccine-preventable disease. We show that a formal game theoretical analysis of this problem leads to new insights that help to explain human decision-making with respect to vaccination. Increases in perceived vaccine risk will tend to induce larger declines in vaccine uptake for pathogens that cause more secondary infections (such as measles and pertussis). After a vaccine scare, even if perceived vaccine risk is greatly reduced, it will be relatively difficult to restore prescare vaccine coverage levels.

University students immunized and not immunized for measles: a comparison of beliefs, attitudes, and perceived barriers and benefits

OBJECTIVE

To compare students who were immunized or not immunized during the 1997 Simon Fraser University measles outbreak in British Columbia.

METHODS

Descriptive comparative study using the Health Belief Model as a theoretical framework. A self-administered questionnaire was mailed to a stratified random sample of 400 immunized and 400 non-immunized SFU students.

RESULTS

Perceived susceptibility, severity, barriers, cues to action, threat and student age were significantly related to being immunized. Logistic regression analysis achieved an overall correct prediction rate of 84.7% by including the contribution of the four variables of susceptibility, barriers, cues to action, and health motivation. Content analysis of the non-immunized students' descriptions of what it would have taken for them to be immunized indicated the influence of these four variables.

DISCUSSION

The Immunization Health Belief Model Scale is a valuable tool for ascertaining attitudes and beliefs relating to immunization decision-making. Interventions targeted to significant beliefs may increase immunization coverage levels and result in improved disease prevention.

University students immunized and not immunized for measles: a comparison of beliefs, attitudes, and perceived barriers and benefits

OBJECTIVE

To compare students who were immunized or not immunized during the 1997 Simon Fraser University measles outbreak in British Columbia.

METHODS

Descriptive comparative study using the Health Belief Model as a theoretical framework. A self-administered questionnaire was mailed to a stratified random sample of 400 immunized and 400 non-immunized SFU students.

RESULTS

Perceived susceptibility, severity, barriers, cues to action, threat and student age were significantly related to being immunized. Logistic regression analysis achieved an overall correct prediction rate of 84.7% by including the contribution of the four variables of susceptibility, barriers, cues to action, and health motivation. Content analysis of the non-immunized students' descriptions of what it would have taken for them to be immunized indicated the influence of these four variables.

DISCUSSION

The Immunization Health Belief Model Scale is a valuable tool for ascertaining attitudes and beliefs relating to immunization decision-making. Interventions targeted to significant beliefs may increase immunization coverage levels and result in improved disease prevention.

The average cost of measles cases and adverse events following vaccination in industrialised countries

BACKGROUND

Even though the annual incidence rate of measles has dramatically decreased in industrialised countries since the implementation of universal immunisation programmes, cases continue to occur in countries where endemic measles transmission has been interrupted and in countries where adequate levels of immunisation coverage have not been maintained. The objective of this study is to develop a model to estimate the average cost per measles case and per adverse event following measles immunisation using the Netherlands (NL), the United Kingdom (UK) and Canada as examples.

METHODS

Parameter estimates were based on a review of the published literature. A decision tree was built to represent the complications associated with measles cases and adverse events following immunisation. Monte-Carlo Simulation techniques were used to account for uncertainty.

RESULTS

From the perspective of society, we estimated the average cost per measles case to be US$276, US$307 and US$254 for the NL, the UK and Canada, respectively, and the average cost of adverse events following immunisation per vaccinee to be US$1.43, US$1.93 and US$1.51 for the NL, UK and Canada, respectively.

CONCLUSIONS

These average cost estimates could be combined with incidence estimates and costs of immunisation programmes to provide estimates of the cost of measles to industrialised countries. Such estimates could be used as a basis to estimate the potential economic gains of global measles eradication.

Measles-mumps-rubella and hepatitis B vaccination uptake in adolescents: a survey in metropolitan Melbourne

OBJECTIVE

To measure the uptake of preadolescent measles-mumps-rubella (MMR) and adolescent hepatitis B vaccinations and assess the influence of certain demographic factors on the uptake of these vaccines.

DESIGN

Prevalence surveys of uptake rates of preadolescent (school Year 6; age 10-11 years) MMR and adolescent (school Year 9; age 13-14 years) hepatitis B vaccination.

SETTING

City of Darebin, an inner northern metropolitan region of Melbourne, 1996.

SUBJECTS

1160 Year 6 school students (580 boys) and 1102 Year 9 school students (548 boys).

INTERVENTION

School-based vaccination program administered by Darebin Council.

RESULTS

83% of Year 6 students were vaccinated with the MMR vaccine (84.1% of girls and 81.9% of boys). 71.6% of Year 9 students completed the full course of hepatitis B vaccination (68.9% of boys and 74.2% of girls). There was a higher uptake of MMR in non-government primary schools, but no other demographic factors (sex, economic status, non-English-speaking background, parental education, school class size) were associated.

CONCLUSIONS

These uptake rates do not meet National Health and Medical Research Council (NHMRC) recommendations. Further study is required to determine and quantify the factors that affect vaccination uptake in adolescence. Programs may then be developed to improve vaccination uptake.