Universal Immunization Program Research Articles

Immunization Against Viral Respiratory Disease

Healthy and at risk children are susceptible to the morbidity and mortality associated with viral-induced respiratory diseases, including respiratory syncytial virus (RSV) and influenza. The World Health Organization is attempting to develop and distribute effective vaccines to prevent/reduce key viral respiratory diseases. The goals of a vaccination program for viral respiratory infections include the prevention of lower respiratory tract infections and prevention of infection-associated morbidities, hospitalization and mortality. This article explores influenza and RSV vaccine developments. There are 2 influenza vaccines, trivalent inactivated and live, cold-adapted, attenuated. Trivalent inactivated vaccine is indicated for persons older than 6 months of age. Currently <10%, <30% and <30% of healthy children, healthy adults and high risk children, respectively, are vaccinated. Efficacy is from 70 to 90% in healthy adults younger than 65 years of age and 30-90% in children, with lower efficacy in younger children. Live, cold-adapted, attenuated vaccine is indicated for healthy persons 5-49 years of age and usually is 70-90% effective. Various RSV vaccine formulations are being investigated. The Advisory Committee on Immunization Practices (ACIP) recommends influenza vaccination for children 6-23 months old. Studies support immunization of all children, not only those at high risk. Current ACIP recommendations focus on high risk persons and do not include school age children. A universal immunization program for all children could benefit the entire community. Effective vaccines are available for some viral respiratory pathogens (eg, influenza virus), but not for most mucosally restricted respiratory viral pathogens. Research should continue into safe and effective vaccines for all childhood viral illnesses.

Seroprevalence of markers of viral hepatitis in Yemeni healthcare workers.

The seroprevalence of viral hepatitis in healthcare workers has important public health implications. To assess the risk factors for the acquisition of viral hepatitis in an unvaccinated cohort from an hyperendemic region, 567 healthcare workers from a large hospital in the capital of the Republic of Yemen were interviewed and tested for serological markers of infection with viral hepatitis. 54/543 (9.9%) tested positive for hepatitis B surface antigen (HBsAg), 174/543 (32.0%) had positive hepatitis B core antibodies (anti-HBc), and 19/546 (3.5%) had hepatitis C antibodies (anti-HCV). Age (OR = 1.04, 95% CI 1.02-1.06), male sex (OR = 2.0, 1.32-3.03), and occupation (healthcare workers not carrying out exposure prone procedures, OR = 1.61, 1.06-2.44) were found to be independent predictors for the likelihood of detecting either HBsAg or anti-HBc by multivariate logistic regression analysis. No independent risk factors for anti-HCV positive status were identified. Our findings support the adoption of universal HBV immunisation programmes and infection control precautions. The absence of known risk factors predicting anti-HCV positive serostatus suggests the main mode of transmission of hepatitis C in this cohort in the Yemen remains undiscovered.

Canada's first universal varicella immunization program: Lessons from Prince Edward Island.

A live attenuated varicella vaccine was licensed in Canada in December 1998. The first universal varicella immunization program in Canada was initiated in Prince Edward Island in 2000. Students in grades one to six without a history of varicella were offered the vaccine, administered by Public Health Nurses, in school clinics during February and March 2000. The acceptance rate ranged from 29.1% of all grade one students to 9.8% of all grade six students; overall, 18.8% of students received the vaccine. A universal program for children 12 months of age was introduced on April 1, 2000 and catch-up clinics for those between 12 months of age and those in grade one were introduced in June 2000. Repeated media announcements and the cooperation of staff in schools and daycare facilities assisted in informing parents about the availability of the vaccine. Vaccine-associated adverse events have been uncommon and the vaccine has been well accepted.

The Universal Immunisation Programme: An Evaluation Based on a Social Marketing Perspective

This paper is about comparison from a social marketing perspective, based on secondary data, of the programme constituents and achievements of the Universal Immunisation Programme (UIP) on the one hand and the Pulse Polio Immunisation programme on the other. Implications of the comparison are noted for the benefit of increasing the effectiveness of the UIP as well as to improve the design of similar initiatives in future.

Estimation of Annual Risk of Infection of Tuberculosis in District Patiala, INDI

PURPOSE: Epidemiological situation of tuberculosis needs to be studied in order to have baseline data and to formulate strategies and to see the impact of such strategies for control of tuberculosis. Various epidemiological indices like tuberculin test, chest X-ray, sputum examination and mortality rate etc. have been used in the past to study the epidemiological situation. However in the given scenario of high prevalence of tuberculosis and large population these methods are found to be expensive and time consuming. Annual risk of infection (ARI) is one epidemiological indices which has been found to be useful to study the epidemiological situation because it is easy to perform and is cost effective. However there is controversy about the study of ARI in BCG vaccinated children. In the era of universal immunization program (UIP) it is very difficult to find sufficient number of non BCG vaccinated children. Therefore ARI was estimated amongst BCG vaccinated and non BCG vaccinated children.

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

BackgroundEven 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.MethodsParameter 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 imminisation. Monte-Carlo Simulation techniques were used to account for uncertainty.ResultsFrom 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.ConclusionsThese 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.

Can a universal influenza immunization program reduce emergency department volume?

In 2000 the Ontario Minister of Health and Long-Term Care announced a universal influenza immunization program for Ontario, Canada. The 2 objectives of this $38-million program were to decrease seasonal impact of influenza on emergency department (ED) visits and to decrease the number and severity of influenza cases. This paper examines the correlation between population influenza rates and ED visits in 5 tertiary care hospitals in Ontario over a 5-year period (1996-2001). In this retrospective, observational study, we determined the total number of ED visits during the study period, by month, at 5 tertiary care hospitals in 3 Ontario cities Kingston, London and Ottawa). Detailed ED diagnoses were captured for Kingston, and provincial and national population-based influenza rates were obtained from Health Canada for the 5-year study period. Correlation and regression analyses were used to determine the relationship of influenza rates and ED volumes. "Influenza season" is defined in this study as November 1st to March 31st of each year. There was no significant correlation between influenza rates and ED volumes, with Pearson correlation coefficients (r) of 0.22 (p = 0.72), 0.33 (p = 0.59) and 0.27 (p = 0.66) at the Kingston, London and Ottawa study sites, respectively. Data from the Kingston hospitals showed that, during influenza season, acute respiratory diagnoses accounted for only 4.4% of ED visits and influenza for only 0.34% of visits. Multiple linear regression analysis showed that the ED diagnosis of influenza was not significantly related to ED volume. During the influenza season after the universal immunization campaign, ED visits increased at all sites. Based on this study, a universal influenza immunization campaign is unlikely to affect ED volume.

Child mortality rates in rural India: an experience from the Ballabgarh project.

In a special project area of rural India, the age-specific mortality rates of a birth cohort 0-59 months old were calculated from 1991 to 1999. The mortality rates were lower than the national average, but the common causes of child deaths were similar. Since 1985, when the Universal Immunization Programme of India introduced routine measles vaccination, there has been a proportionate decline in child deaths unlike other parts of India. The absolute numbers of child deaths from 'all' causes have also declined significantly over the same period of time. The vaccination coverage in the project area is higher than the national average. This suggests a possible 'beneficial' non-specific effect of measles vaccination on child survival over this time period.

Hepatitis B control in Europe by universal vaccination programmes: the situation in 2001.

In the nine years since the Global Advisory Group of the Expanded Programme on Immunisation (WHO) set 1997 as the target for integrating hepatitis B vaccination into national immunisation programmes worldwide, 129 countries have included hepatitis B vaccine as part of their routine infant or adolescent immunisation programmes (June 2001). By the end of 2002, 41 out of the 51 countries of the WHO European Region will be implementing universal hepatitis B immunisation. The rewards of effective implementation of the programmes in countries that started 10 years ago are becoming apparent; and their success offers an exemplary model for other countries. Some other countries, however, have difficulties to incorporate hepatitis B vaccine into universal childhood immunisation programmes, because of major economic constrains and the inability to procure a constant vaccine supply. The next decade will be characterised by expanded use of hepatitis B vaccines and the increasing efforts to sustain vaccine programmes and make the vaccine available to those countries and regions that cannot afford it. In Europe, as well as in the rest of the world, work still remains to be done to support and implement interventions that will bring us closer to the WHO goal and to eradicate hepatitis B.

The sustainability of hepatitis B immunization within the Universal Immunization Programme in India.

Based on the recommendations of the World Health Organization, India as a member-state is likely to implement universal immunization against hepatitis B through the existing Universal Immunization Programme (UIP). A pilot project is already under progress in two municipal zones of Delhi. This paper begins by reviewing epidemiological features of hepatitis B in India, some established aspects and other emerging trends. The gaps in the existing knowledge base are also given due consideration. The current recommendation is to deliver the vaccine at zero-day for infants in the absence of facilities for antenatal screening and immunoglobulin administration. The paper explores the potential pitfalls for integrating the proposed hepatitis B vaccination with the DPT (diphtheria/pertussis/tetanus) schedule. Based on the findings of the National Family Health Survey, the likely coverage for the states is estimated for both the schedules--zero-day and with DPT. The performance of the pilot phase is reviewed through the results of a coverage survey. The paper also estimates the resources that should be committed to launch the universal immunization of hepatitis B vaccination and the sustainability issues thereof. The paper finally concludes with the position that hepatitis B immunization will 'sink or sail' with the UIP. Further, this should act as an engine for recharging the infrastructure and functioning of the public health system and promote general preventive practices like universal precautions.

Prevalence of hepatitis B virus infection and related risk factors in a rural community of Mexico.

A cross-sectional survey of the seroprevalence of hepatitis B virus (HBV) markers among healthy people was conducted in San Juanito, a rural community in the northern state of Chihuahua, Mexico. The overall prevalence in 970 people was 6.6% for antibody to hepatitis B core antigen. There was an age effect on the prevalence of HBV infection, and a gradual increase in prevalence was observed in patients up to the age of 40 years. Those subjects with a history of dental procedures had a 2-fold higher risk for HBV infection (odds ratio [OR], 2.4; 95% confidence intervals [CI], 1.01-5.86), and there was a 74% increased risk for each blood product transfusion (OR, 1.74; 95% CI, 1.09-2.77). Horizontal transmission seems to be the major source of endemicity in San Juanito because no woman was a chronic carrier. To lower HBV transmission rate, an adequate active screening program for blood donors should be implemented, together with a universal infant immunization program.

Immunisation status of children in BIMARU states.

To assess the immunisation status of children in the states of Bihar, Madhaya Pradesh, Rajasthan and UP the evaluation covered BCG, DPT, OPV, Measles, Pulse Polio and Vitamin A. WHO 30 cluster survey methodology with certain modifications incorporating information on sex of the child, literacy of parents and distance of the village was used. Study covered 30 districts, 900 villages and 6300 children. About 48 per cent of children received all the vaccines (BCG, DPT, OPV, Measles) in these states as compared to 63 per cent at All India level. These states accounted for about 70 per cent of non-immunised children. The coverage levels were lower for children of illiterate mothers and in small, inaccessible and triple villages. The literacy of mother is the key to the success of the Universal Immunisation Programme (UIP). Information, Education and Communication (IEC) activities should specially be targeted to educate the moters in rural areas. The underserved areas of these four states should have special focus in the programme and hence the tribal, small and inaccessible villages in the coverage should be focused and targeted, immediate improvement in the coverage could also be achieved by better follow-up and reducing drop-out rate.

Comparing Benefits and Risks of Immunization

This paper uses a straightforward method of quantifying the benefits and risks of immunization, illustrated by universal immunization programs in British Columbia against invasive Haemophilus influenzae type b disease (Hib), measles, rubella, and paralytic poliomyelitis. Data were extracted from provincial communicable disease and vaccine adverse event surveillance systems. Average disease incidence was compared before and after implementing universal immunization programs. Estimates of prevented deaths and serious disease complications were calculated and compared with expected numbers of serious vaccine-associated adverse events (VAAEs). Average incidence of reported cases decreased 90 to 100% over a 5-year period after implementing universal programs. These benefits were sustained or strengthened over time. Rates of reported serious VAAEs were low. The remarkable success of immunization has created a paradox. Despite a low absolute risk of serious VAAEs, the relative risk of some VAAEs can exceed risk of disease in the province.

Ethics and immunization policy: promoting dialogue to sustain consensus.

The societal consensus that has supported the United States' universal childhood immunization programs for the past 50 years shows signs of eroding. This article proposes a systematic approach to evaluate immunization policy options. Through a unifying framework that combines epidemiologic, economic, and ethical concerns, this approach promotes a clearer understanding of underlying issues and inherent tradeoffs between alternative policies. Such a systematic examination of policy options could facilitate the public dialogue necessary to continually recreate a broad consensus on immunization practices and enable us to choose policies most in accord with our fundamental values.

Hepatitis Vaccines

The development of highly effective and safe inactivated HAV vaccines and highly effective and safe recombinant HBsAg subunit HBV vaccines represents major advances in the control of viral hepatitis, but many challenges remain. Because current HAV immunization recommendations target high-risk groups only, infection rates are unlikely to fall dramatically until universal childhood immunization programs are implemented. Routine HBV vaccination of infants, children, adolescents, and individuals at high risk will reduce the incidence of infection, but vaccine nonresponsiveness and escape mutants are important potential challenges. Whether either HAV or HBV vaccine provide lifelong protection remains to be determined. Vaccines for HDV, HEV, and HCV are not yet available.

New vaccines and the rising costs of caring

Vaccines that are used in universal immunization programs for children have been highly effective in controlling, even eliminating, target illnesses. They have done so at remarkably little cost to taxpayers. Relative to the averted costs of caring for patients with the target illnesses and their sequelae, current universal vaccination programs actually save money for governments. The cost-sparing effect was estimated to be 10-fold with diphtheriapertussis-tetanus vaccines, the simple nature of which resulted in manufacturing costs well under $1/dose. Later vaccines involved increasingly sophisticated manufacturing processes and, consequently, higher costs. One can imagine the skill and labour involved in coaxing a batch of live measles or polio vaccine virus to completion in huge tissue culture tanks, and the precise chemistry required to conjugate the Haemophilus influenzae type b polysaccharide to a carrier protein in a consistent fashion. Nevertheless, the newer products were still cost sparing in universal programs.

Aetiological investigations of hearing loss in childhood: a review.

Advances in genetics, improvements in neonatal intensive care and the introduction of universal immunisation programmes have resulted in major changes in the epidemiology of hearing loss in children. Perinatal factors now account for 27% of the child population with hearing loss, compared to 2% about 25 years ago. 1 In the UK, the prevalence of hearing impairment in children with a history of treatment in the neonatal intensive care unit has increased fourfold over a period of 15 years, 2 and is higher than in other European countries. 3 A combination of neonatal intensive care unit status, family history of hearing loss and craniofacial abnormality noticeable at birth may account for up to 64% of all types of hearing loss. 2 The overall prevalence of bilateral hearing loss in children is estimated to be between 0.5/1000 live births 4 to 1.2/1000 2 and up to 2.1/1000 5 in different studies, depending on factors such as methods of hearing loss ascertainment, degree of hearing loss targeted, geographical area and time period of the study. Investigation of the hearing impaired child aims to identify the cause of the hearing loss and to provide information relevant to hearing loss management, coexisting medical problems and prognosis for the child and the family. In addition, these investigations may also help to clarify phenotypes in genetic hearing loss and to provide a more accurate picture of epidemiology, which is necessary for planning effective hearing loss prevention and surveillance programmes. The objective of this paper is to review the current literature on this topic and to assist the clinician in devising an investigative plan for this population.

Measles, Mumps and Rubella Vaccine

The current state of knowledge regarding the safety of measles, mumps and rubella vaccine (MMR) is reviewed. Although there are known adverse reactions to the vaccine, the majority are relatively minor and have no long term consequences, and those that do have long term consequences are extremely rare. Contraindications, known adverse reactions that may follow MMR immunisation, publicised adverse events for which a causal association with MMR has not been established, and the complications that may follow an infection with wild-type measles, mumps or rubella, are discussed. The article also discusses, with examples, the misleading information that can be obtained on the internet and in the public press. It is vital that the general public have an understanding of the great benefits and low risks associated with the use of MMR vaccine, because it is important that they consent to the administration of MMR vaccine to their children in order to ensure the success of universal immunisation programmes and the control of measles, mumps and rubella. Therefore, it becomes increasingly important for health professionals to use innovative education methods to promote immunisation and counteract the incorrect and misleading information that is readily available on the internet and in the media.

Cost-effectiveness analysis of a rotavirus immunization program for the United States.

Rotavirus is the most common cause of severe diarrhea in children, and a live, oral vaccine may soon be licensed for prevention. To estimate the economic impact of a national rotavirus immunization program in the United States. Cost-effectiveness was analyzed from the perspectives of the health care system and society. A decision tree used estimates of disease burden, costs, vaccine coverage, efficacy, and price obtained from published and unpublished sources. The proposed vaccine would be administered to infants at ages 2, 4, and 6 months as part of the routine schedule of childhood immunizations. Total costs, outcomes prevented, and incremental cost-effectiveness. A routine, universal rotavirus immunization program would prevent 1.08 million cases of diarrhea, avoiding 34000 hospitalizations, 95000 emergency department visits, and 227000 physician visits in the first 5 years of life. At $20 per dose, the program would cost $289 million and realize a net loss of $107 million to the health care system-$103 per case prevented. The program would provide a net savings of $296 million to society. Threshold analysis identified a break-even price per dose of $9 for the health care system and $51 for the societal perspective. Greater disease burden and greater vaccine efficacy and lower vaccine price increased cost-effectiveness. A US rotavirus immunization program would be cost-effective from the perspectives of society and the health care system, although the cost of the immunization program would not be fully offset by the reduction in health care cost of rotavirus diarrhea unless the price fell to $9 per dose.

Hepatitis B immunization in a low-incidence province of Canada: comparing alternative strategies.

This study provides a comparative cost-effectiveness analysis of three universal immunization programs for hepatitis B virus (HBV). Using three theoretical cohorts of infants, 10-year-olds, and 12-year-olds, a universal immunization program was compared with a prenatal screening/newborn immunization program involving testing of prepartum women and immunization of newborns of HBsAg-positive mothers. A Markov long-term outcome model used Manitoba data to estimate costs and health outcomes across the lifespan. The model was based on an HBV incidence rate of 19/100,000 and a discount rate of 5% and incorporated the most recent treatment advances (interferon therapy). Cost-effectiveness was calculated as the ratio of dollars spent per year of life saved, with costs determined from the perspective of a third-party payer. The universal infant-immunization program, although not cost-saving, was associated with a low, economically attractive cost-effectiveness ratio of $15,900 (Canadian) per year of life saved, a figure substantially lower than the ratios of $97,600 and $184,800 (Canadian) associated with the universal programs for 10- and 12-year-olds, respectively. Cost-effectiveness ratios were found to be sensitive to changes in immunization costs, HBV incidence rates, and the rate at which protective antibody levels are lost over time: If these variables move in the directions suggested by current trends, the authors anticipate an increasing economic appeal of universal programs well into the future. A universal program of HBV immunization for infants appears to be economically practical in regions where HBV infection rates are low and stable.