Analysis of Child Immunisation Programmes

Analysis of Child Immunisation Programmes Introduction Child immunisation programmes rank highly among the most successful public health interventions and are believed to have contributed substantially to the overall increase in life expectancy observed during the 20th century (Gellin et al. 2000). Global immunisation coverage has increased considerably since the introduction of the WHO Expanded Programme on Immunization in 1974. It is estimated that twenty million deaths have been prevented through immunisation over the past twenty years (Tickner et al. 2006) and many vaccine-preventable diseases such as diphtheria, tetanus, measles, mumps, rubella and polio are now rare in developed countries (Bardenheier et al. 2004). However, in countries including the UK, there are fears that immunisation programmes may have become victims of their own success. Low prevalence rates of vaccine-preventable diseases have led to public belief that these diseases no longer pose a serious health risk, while concerns over the safety and side effects of vaccines are now greater than those relating to the diseases these vaccines were designed to prevent. The past thirty years has seen continuing controversy over vaccine safety. Concerns over the whole-cell pertussis (whooping cough) vaccine were first raised during the 1970s following a study which reported severe neurological complications in children following immunisation with DTP, a combined vaccine for diphtheria, tetanus and pertussis (Kulenkampff et al. 1974). Controversy surrounding the measles, mumps and rubella (MMR) triple vaccine followed in the early 1990s after widespread reports suggested a link between this vaccine and both autism and bowel disease. In a study of 12 children referred to a paediatric gastroenterology unit with concurrent developmental regression and gastrointestinal problems, nine developed autism. The parents of 8 of these children associated the onset of their condition with MMR vaccination (Wakefield 1998). While more recent research has shown these fears to be unfounded (Peltola et al. 1998; Taylor et al. 1999), some parents remain unconvinced and vaccine uptake has fallen across the UK, with decreases in MMR uptake of up to 30% in some regions. Declining vaccine coverage rates are also linked to disease outbreaks. A 30% drop in uptake of the pertussis vaccine was recorded following extensive adverse media publicity in 1974 (discussed previously), which was then followed by an epidemic of pertussis (Vernon 2003 ). Similarly, since the decline in MMR coverage, outbreaks of measles have been reported in a number of European countries including the UK, Ireland, Germany, Italy, Denmark and the Netherlands (Department of Health 2004). Suboptimal vaccine uptake has also been reported for other vaccines including diphtheria, tetanus and polio (Tickner et al. 2006). Although the trend for decreased vaccine uptake appears to be reversing in recently years, many Primary Care Trusts (PCTs) in England are still failing to reach the 95% uptake target recommended by the WHO, which is essential to achieve ‘herd immunity’, i.e. where a sufficiently high proportion of the population is immune to a particular disease, thereby preventing transmission of the infectious organism (Health and Social Care Information Centre 2005). For example, data collected in 2004–2005 demonstrated an MMR uptake of 81% across England, a 1% increase on the previous 8-year period. It should be also noted that considerable regional variations were observed, with rates below 70% by some PCTs (Henderson et al. 2008). Immunisations frequently require multiple doses for maximum disease protection. Between 5–10% of children remain unprotected after the first dose of the MMR vaccine, whereas this is reduced to below 1% after the second dose (Tickner et al. 2006). However, there is evidence of poor compliance with childhood immunisation schedules. A study involving a cohort of 18,819 infants in the UK reported that 3.3% were partially immunised, compared with 95.6% of fully immunised infants (Samad et al. 2006). In the UK, statistics show that among children who reached the age of 5 years in 2004-2005, uptake levels of the primary immunisation of diphtheria, tetanus and polio vaccine plus the pre-school booster vaccination were 14% lower than those of the primary immunisation alone (Health and Social Care Information centre 2005). Similarly, uptake of the first and second doses of the MMR vaccine was 16% lower than the first dose alone. This pattern of poor compliance has also been observed in other countries including Sweden and Australia (Heiniger and Zuberbuhler 2006; Ferson et al. 1995). In order to maximise vaccine coverage rates, a full understanding of the factors affecting vaccination uptake and compliance is required, both to identify and address existing unmet needs and to develop and implement effective health promotion strategies. In the case of childhood immunisation, it is also important to consider how parental knowledge, attitudes and beliefs may influence decision-making regarding immunisation. The aims of this review are to explore those factors associated with low rates of vaccination uptake in children and poor compliance with immunisation schedules, with particular emphasis on the knowledge, attitudes and concerns of those parents who decide not to immunise their children. The specific objectives are to perform a search to identify relevant published literature, critique selected articles using an appropriate conceptual framework, and discuss the relevance and implications of the findings of this research. Overview [Client: this section isn’t really an overview, more background material – you may therefore wish to consider re-naming this as ‘Background’] Public health within the UK Public health may be defined as â€Å"the science and art of preventing disease, prolonging life, and promoting health throughout the organised efforts of society† (Acheson 1988). Public health services within the UK cover a broad range of areas which include general health (e.g. issues such as obesity, smoking and blood pressure), environmental health (e.g. food hygiene and pest control) and disease. The NHS national immunisation programme which focuses on childhood immunisation against diseases including tetanus, diphtheria and polio forms a key component of public health provision within the UK (NHS 2007). The public health system comprises a number of core functions which include the health surveillance and monitoring the health status of communities, identifying health needs, developing disease screening and prevention programmes, managing health promotion, and evaluating the provision of health care (Department of Health 2008). Principles of immunisation [Client: I’ve assumed a detailed knowledge of immunity is already held and have therefore kept this section brief] Immunisation may be active or passive. Whereas passive immunisation provides short-term protection, active immunisation also known as vaccination induces protective long-lasting immunity. Active immunisation involves the administration of an antigen which elicits an immune response similar to that which a naturally-acquired infection (Robinson and Roberton 2003). This response results in the development of immunological memory and is achieved through the activation of both T and B cells, which produces a high yield of memory cells which, after initial exposure, are able to recognise a particular antigen again in the future. Active immunisation can be performed using live or killed whole organisms, components of organisms such as subunits, or fractionated or recombinant (manufactured) vaccines (Robinson and Roberton 2003). Importance of immunisation programmes Immunisation programmes play a key role in the control of infectious disease. Disease-related morbidity and mortality places a substantial burden on healthcare systems and preventing individuals from becoming ill is more favourable in terms of healthcare-associated costs than treating them once they are ill. Immunisation has a direct effect by offering protection to the immunised individual and an indirect effect by reducing the incidence of disease among others, (i.e. by providing herd immunity) since vaccinated individuals are less likely to act as a source of infection, unvaccinated individuals have less chance of being exposed to that infection, thus vaccination also benefits the community (ScotPho 2008). If vaccine coverage rates are high enough to induce high levels of herd immunity within a population, it is possible for a disease to be eradicated, as illustrated by the global eradication of smallpox in 1980. However, if high coverage rates are not sustained, the disease coul d return. Immunisation programmes may be aimed at children, adolescents or adults. Routine immunisation against measles, polio, diphtheria, tetanus, pertussis and tuberculosis is now provided in all developing countries but many countries also include a wider range of immunisations against influenza, mumps (usually in combination with measles and rubella) and predominant strains of pneumococcal disease (WHO 2005). In addition, hepatitis B immunisation is also recommended by WHO for all countries, while Haemophilus influenzae type b (Hib) is recommended for those countries with a significant disease burden and who have sufficient resources (WHO 2005). UK childhood immunisation programme The UK immunisation programme for children and adolescents from birth to the age of 18 years is shown in Table 1 below. Each vaccination is administered as a single injection into either the thigh or upper arm. The use of combination vaccines is advantageous in reducing the number of injections administered. For example, children in the UK receive only 7 vaccinations before the age of 15 months, instead of the 21 single-antigen injections they would otherwise receive. In the US, children receive up to 21 injections by the age of 15 months (CDCP 2006). Vaccinations are not mandatory in the UK and are offered free of charge by the NHS. This is in contrast to countries such as the United States and Australia where vaccination is compulsory (Salmon et al. 2006) and proof of immunisation is required for school entry (Vernon 2003). However, despite the lack of a mandatory immunisation policy, coverage rates in the UK are still high compared with many other developed countries, although the current levels of MMR coverage are cause for concern. Table 1. UK childhood immunisation programme (from NHS 2007). When to immunise Diseases protected against Vaccine given Routine immunisation Two months Diphtheria, tetanus, pertussis (whooping cough), polio and Haemophilus influenzae type b (Hib) Pneumococcal infection DTaP/IPV/Hib + Pneumococcal conjugate vaccine Three months Diphtheria, tetanus, pertussis, polio and H. influenzae type b (Hib) Meningitis C DTaP/IPV/Hib + MenC Four months old Diphtheria, tetanus, pertussis, polio and H. influenzae type b (Hib) Meningitis C Pneumococcal infection DTaP/IPV/Hib + MenC + PCV Approx. 12 months H. influenzae type b (Hib) Meningitis C Hib/MenC Approx. 13 months Measles, mumps and rubella Pneumococcal infection MMR + PCV Between 3 years 4 months and 5 years Diphtheria, tetanus, pertussis and polio Measles, mumps and rubella DTaP/IPV or dTaP/IPV + MMR 13–18 years Tetanus, diphtheria and polio Td/IPV Non-routine immunisation At birth (to babies who are more likely to come into contact with TB than the general population) Tuberculosis BCG At birth (to babies whose mothers are hepatitis B positive) Hepatitis B Hep B Literature review A literature search of English language articles was performed using the electronic databases Pubmed and CINAHL. Search terms included: immunisation OR vaccination plus uptake OR compliance OR parent AND belief OR attitude OR knowledge. A number of conceptual frameworks have been developed for use in the critique of both quantitative and qualitative research (Cormack 2000). In this paper, the framework proposed by Cormack (2000) was employed both in the initial selection of relevant, high-quality research articles and in the subsequent critique of those articles. The use of evidence-based practice is necessary to provide high-quality healthcare, and it is therefore essential that all healthcare providers possess the understanding and expertise to review and evaluate published research. By following Cormack’s framework, an informed judgement can be made regarding the findings of a particular research article and their relevance and implications for practice. A total of 8 articl es, including both quantitative and qualitative research, were selected for this review. The article by Gellin et al. (2000) describes a telephone survey study conducted in the United States which investigated parents’ understanding of vaccine-preventable diseases and immunisation practices and procedures. The article abstract is concise, informative and presents the main points of the study in a clear and easy to understand way. The introduction provides the relevant background information needed to set the study in context and clearly states the aims of the research. Study participants were recruited via random digit dialling which is a widely accepted method of ensuring selection of a random population sample. The selection criteria are stated and the study sample size (n=1600) was large enough to yield a confidence interval of  ±2.5% for the population overall. The survey was conducted using by trained market researchers using a pre-tested scripted interview but a full list of the questions is not provided in the article, nor is the script included as an app endix. Further, no mention is made of ethical considerations such as confidentiality or the right to withdraw participation. The statistical analyses used to analyse the data are described fully. The results section of the article is well structured and clear with appropriate use of tables to present data. However, for additional clarity, it may have been better to present the demographic characteristics of the study respondents in a table rather than as a list of percentages in the main text. Results showed that 87% of study respondents believed immunisation to be extremely important and believed there to be a high level of overall vaccine safety (X2=8.6; standard deviation (SD)=1.6). Respondents were asked to state their level of agreement with a series of belief statements. Findings showed that while the majority of respondents held beliefs that were consistent with the available evidence on vaccine efficacy and safety, misconceptions were held by a substantial number of respondents. For example, 25% believed their child’s immune system could become weakened as a result of too many immunisations, while 23% believed that children got more immunisations than were good for them. Doctors were cited as the key providers of information on immunisation. The article includes a comprehensive discussion of the relevance of the study findings with reference to other published research and addresses the limitations of the study (e.g. only those households with telephone could be contacted via random digit-dialling and the inclusion of English-speaking participants only). A separate conclusions section is not included but the implications of the research are discussed in the context of the future of immunisation programmes and public health. The paper by Pareek and Pattison (2000) reports the findings of a prospective cross-sectional UK survey to investigate the factors which influence the intention of mothers to vaccinate their children with the two-dose MMR vaccine. The paper contains a well-structured abstract that present the main points of the study. The introduction is comprehensive with clearly stated aims and lists the theoretical framework used in the study (i.e. the Theory of Planned Behaviour). Study participants were randomly selected from confidential records held by Birmingham Health Authority, after written consent had been obtained. A total of 300 mothers of children aged between either 5-12 months or 21-35 months received a pre-piloted 48-item questionnaire with the assurance of confidentiality. The full questionnaire is not provided but a list of the three sections in the questionnaire is given. The response rate was 59%. A brief description of the statistical analyses used to analyse the data is given. The results section is unstructured making if difficult to read but is comprehensive in nature. No figures or tables are included. Results showed that significantly fewer mothers intended to take their children for their second MMR immunisation (Group 2), compared with the number intending to take their child for their first immunisation (Group 1) (Group 1: 87% vs Group 2: 78%; p Kennedy et al. (2005) reported the findings of an analysis of data from the 2002 annual, mail panel survey of adults in the United States performed to examine the socio-demographic factors and immunisation beliefs/behaviours associated with parental opposition to compulsory vaccination. This article contained a brief abstract which nonetheless detailed the key points of the study but did not list the number of study participants. A comprehensive introduction is included with extensive reference to other published research and the aims and objectives of the study are given, together with the model used (i.e. the Health Belief Model). The method of study participant recruitment is described but this is confusing and difficult to follow. In summary, a total of 6,027 adults received surveys with a response rate of 73%. However, these individuals were not selected randomly. The questions in the survey are not listed and a copy of the questionnaire is not included. However, responses to relevant beliefs statements are listed in a table in the results section, which provides the reader with some insight into what was included. No mention is made of ethical considerations. The statistical analyses used are described adequately. The results section is clear and well-structured with tabulation of relevant data. Study findings showed that 12% of respondents were opposed to compulsory vaccination. Compared with parents who were supportive of compulsory vaccination, those who were opposed were significantly more likely to agree that the ‘the body can protect itself without vaccines’ (opposed 24% vs supportive 10%; pvs 17%; pvs 32%; pvs 13%; p Sporton and Francis (2001) performed a study to explore the decision-making process of parents who have chosen not to have their children immunised. Their paper contains a very detailed abstract which describes the study in detail. A short introduction sets the study in context and includes the rationale for performing the study, with a clearly stated aim. The selection of the 13 final study participants (12 mothers and 1 father) is described in detail and details of ethical approval are included. Semi-structured interviews were used to gather information, a widely accepted method in qualitative research which allows the researcher to be guided by the study participant while still allowing key points to be covered. All interviews were conducted by the same researcher, thus ensuring consistency. Although all interviews were transcribed, no mention of consent or other ethical considerations is made in the paper. The results section has a clear and logical structure with a relevant table and figure. Narrative accounts from the study participants are also included within each section. Findings showed that while parents often cited more than one reason for choosing not to immunise their children, the risk of side effects, particularly long-term effects, was identified as a reason by every parent. Other reasons included moral reasons, alternative methods of protection (e.g. homeopathy), practical reasons (lack of access to clinics) and personal parental experiences of immunisation (e.g. lack of immunisation has not resulted in any adverse effects on their own health). Many parents believed that healthcare providers did not provide balanced information and were unwilling to acknowledge the perceived association between immunisation and adverse effects. The discussion makes very limited reference to other published research an fails to address the limitations of the study (i.e. the extremely limit ed sample size and the extreme bias towards mothers). The conclusion and discussion of implications for the future are brief but adequate. In their recently published article, Pearce et al. (2008) report the findings of a nationally representative UK cohort study performed to estimate uptake of the combined MMR and single-antigen vaccines and explore the factors associated with uptake. This article contains a comprehensive abstract which includes a detailed results section, while the introduction discusses previous research that supports the purpose of the current study. Data from a longitudinal study of 14,578 children born in the UK between 2000 and 2002 were used in this analysis. These data were obtained via face-to-face interviews between trained researchers and the main care giver (usually the mother) conducted at home when the child was approximately 9 months old and again at the age of 3 years but no mention is made of whether consent was obtained from participants. The study sample included adequate representation from all 4 countries within the UK including those from deprived areas and ethnic minorities. A de tailed description of the analysis performed is provided in the paper. Results showed that 6.1% of children in the study were not immunised and that various socio-demographic factors were associated with immunisation uptake. For example, children were less likely to be immunised if they lived in a household with other children or a single parent; if the mother was aged 34 years at the time of the birth; or if the mother was more highly educated, unemployed or self-employed. Ethnicity was also strongly associated with single-antigen vaccine uptake. Almost three quarters (74.4%) of parents who had not immunised their children stated that they had made a conscious decision not to do so. The discussion section addresses the studies strengths (e.g. the large sample size) and limitations (e.g. using maternal report of immunisation status in which only one fifth of participants actually checked their child’s health record) and compares the findings with that of previous research. The implications for future practice and policy-making are discussed in de pth with recommendations and appropriate conclusions have been drawn. Gust et al. (2004) conducted a case-control study in the United States to examine the attitudes, beliefs and behaviours of parents whose children were incompletely immunised, compared with those of fully immunised children. This article includes a well-written abstract that provides the reader with all the relevant information about the study. The introduction refers to existing research and clearly identifies the study’s aims. Both case and control study participants were randomly sampled from children participating in the National Immunization Survey (NIS) and who had adequate provider-reported immunisation data. Case participants were those children who were incompletely immunised with respect to ≠¥2 of diphtheria-tetanus-pertussis (DTP)/diphtheria-tetanus-acellular pertussis (DTaP), hepatitis B and/or measles-containing vaccine (MCV) vaccines (‘incompletely immunised’ defined as The results are presented in a structured, logical way which includes tabulation of the data. Findings showed that among case subjects, 14% of incomplete immunisation was due to parental beliefs, attitudes and behaviours. It is interesting to note that while these beliefs are more common among parents of incompletely immunised children, the parents of fully immunised children also report similar beliefs and attitudes. Parents/guardians of case subjects were more likely not to want their child to receive all immunisations, to rate immunisations as unsafe or somewhat safe and to ask the doctor or nurse not to administer a vaccine to their child for reasons other than illness. The discussion section of this paper is comprehensive but makes limited reference to other published research but the limitations of the study are addressed (e.g. potential inaccurate reporting of beliefs and attitudes through inaccurate recall, due to the length of time since their children were vaccinated). Valu able recommendations are made, together with information to guide the reader to the source of potentially useful educational materials for both healthcare providers and parents. A UK focus group study conducted by Evans et al. (2001) investigated what influences parents decisions on whether to accept or refuse primary MMR vaccination. This article contains a comprehensive abstract that informs the reader about the key points of the study. The introduction is brief but states the study aims. Six focus group discussions (a commonly used method of gathering qualitative data) were held, which were conducted by a moderator using appropriate open-ended questions which are described in the paper. Assistance was provided by a member of the research steering group, thereby ensuring consistency across the groups. A total of 48 participants were recruited purposefully rather than randomly, such that three of the groups contained ‘immunisers’ and three contained ‘non-immunisers’, from a variety of socio-economic backgrounds. Ethical approval was obtained for the study. The methods section describes how data collected was analysed and sorted int o themes. The results section of the article is easy to understand and includes narrative accounts from study participants within each section. All parents who participated in the study believed the decision about whether to vaccinate was difficult and felt under undue pressure from healthcare providers to comply. Four key factors were found to influence parents’ decisions: (1) their beliefs about the risks and benefits of the MMR vaccine and compared with the risk of contracting those diseases; (2) information on the safety of the MMR vaccine; (3) trust in healthcare providers about the accuracy of the advice they had given and attitudes towards this advice; and (4) views on the importance of individual choice. The paper contains a balanced discussion which refers to other published research and includes both recommendations for practice and the limitations of the study (i.e. that over half of study respondents were highly educated, with a mean age of 35 years), and appropriate conclus ions are drawn. Flynn and Ogden (2004) conducted a prospective questionnaire study in the UK to explore which parental beliefs are the best predictors of MMR vaccine uptake. Their paper contains a short abstract which nonetheless details the key points of the study. The introduction to the paper refers extensively to other published research and presents a strong rationale for the study with clearly stated aims. Study participants (n=511) comprised parents whose children were due to receive an invitation for MMR vaccination. A questionnaire was used to gather data, together with additional follow-up data taken from child health records. The various sections within the questionnaire are described in the paper, together with examples of typical questions within each section; however, a copy of the questionnaire is not included. A response rate of 56.9% was recorded. Ethical approval for the study was obtained which also complied with the Data Protection Act. The method used for data analysis is descri bed