Broadening the age restriction for initiating rotavirus vaccination in regions with high rotavirus mortality: Benefits of mortality reduction versus risk of fatal intussusception

Introduction

Recently developed rotavirus vaccines have the potential to reduce diarrhea mortality in children in developing countries. Available data to date do not indicate risk of intussusception with these new vaccines. To avoid a potential unanticipated risk post-licensure, it is recommended that rotavirus immunization be initiated before 12 weeks of age when background intussusception rates are low. This policy could exclude a substantial number of children from vaccination, especially in developing countries where delays in vaccination are common.

Methods

We conducted a scenario analysis to assess the potential benefits of mortality reduction from rotavirus versus the risk of fatal intussusception when the first dose of the vaccine is strictly administered by 12 weeks of age compared with a free strategy with vaccine administered before 1 year of age using data on rotavirus disease, vaccine safety and efficacy, and current diphtheria–tetanus–pertussis vaccination rates, and by incorporating hypothetical risks of intussusception.

Results

In developing countries, assuming vaccine efficacy of 50% and 75% for doses 1 and 2, respectively, and a hypothetical sixfold and threefold increased relative risk of intussusception within 7 days of doses 1 and 2, respectively, initiating rotavirus immunization before 12 weeks of age would prevent 194,564 of the 517,959 annual rotavirus-associated deaths among children <5 years, while potentially resulting in 1106 fatal intussusception events. Administration of the first dose to infants up to 1 year of age would prevent an additional 54,087 rotavirus-associated deaths (total = 248,651) while potentially resulting in an additional 1226 intussusception deaths (total = 2332).

Conclusion

In developing countries, the additional lives saved by broadening the age restrictions for initiation of rotavirus vaccination would far outnumber the hypothetical excess intussusception deaths that would accompany such an approach.     

Acellular pertussis vaccine use in risk groups (adolescents, pregnant women, newborns and health care workers): a review of evidences and recommendations

Background

Pertussis is an acute infectious illness, caused by the bacteria Bordetella pertussis and commonly known as “whooping cough”. Waning immunity after vaccination or after natural infection contributes significantly to the increasing incidence rates in adolescents and adults. Prevention of pertussis in industrialized countries is mainly based on immunization with acellular vaccines in combination with other antigens. A booster dose with an adult-formulation tetanus-diphtheria toxoid and acellular pertussis vaccine (Tdap) is now recommended for all adolescents by several countries, and replacement of the decennial Td dose with a single or more doses of Tdap is recommended for adults.

Objective

Our review aims at describing the current knowledge on the impact of acellular pertussis vaccination in adolescents and adults, with particular focus on specific risk groups: adolescents, pregnant women and their newborns, and health care workers (HCWs), and secondly at suggesting possible immunization strategies.

Methods

Data were retrieved by searches of Pubmed, references, from relevant articles and open-access websites.

Results

In countries where an adolescent booster dose was adopted, a certain decrease of incidence rates was observed. No serologic correlate of protection after immunization exists, but subjects with high antibody levels against pertussis antigens are less likely to develop the disease. Tdap vaccine was demonstrated to induce antibodies to pertussis antigens exceeding those associated with efficacy in infants, in both adolescents and adults. Tdap use in pregnant women seems to be safe and might represent a useful tool in order to prevent pertussis cases in the first months of life. Neonatal immunization with monovalent acellular pertussis vaccine can efficiently prime T and B cells and act as a basis for future immune responses. Cocooning strategies involving all those surrounding newborns have started to be implemented. Their impact on infant pertussis cases will be evaluated in the coming years. Coverage in HCWs should be increased, given their important role in pertussis transmission in health care settings.

Conclusions

Despite the more recent position paper of WHO gives priority to infant and childhood vaccination against pertussis and leaves adolescent, adult and risk group immunization as an option for the future, data are quickly accumulating to support the need to consider pertussis vaccination as a crucial preventative intervention even in adolescents and special risk groups.     

The impact of introducing new vaccines on the health system: Case studies from six low- and middle-income countries

Objective

We aimed to explore the impacts of new vaccine introductions on immunization programmes and health systems in low- and middle-income countries.

Methods

We conducted case studies of seven vaccine introductions in six countries (Cameroon, PCV; Ethiopia, PCV; Guatemala, rotavirus; Kenya, PCV; Mali, Meningitis A; Mali, PCV; Rwanda, HPV). Interviews were conducted with 261 national, regional and district key informants and questionnaires were completed with staff from 196 health facilities. Routine data from districts and health facilities were gathered on vaccination and antenatal service use. Data collection and analysis were structured around the World Health Organisation health system building blocks.

Findings

The new vaccines were viewed positively and seemed to integrate well into existing health systems. The introductions were found to have had no impact on many elements within the building blocks framework. Despite many key informants and facility respondents perceiving that the new vaccine introductions had increased coverage of other vaccines, the routine data showed no change. Positive effects perceived included enhanced credibility of the immunisation programme and strengthened health workers’ skills through training. Negative effects reported included an increase in workload and stock outs of the new vaccine, which created a perception in the community that all vaccines were out of stock in a facility. Most effects were found within the vaccination programmes; very few were reported on the broader health systems. Effects were primarily reported to be temporary, around the time of introduction only.

Conclusion

Although the new vaccine introductions were viewed as intrinsically positive, on the whole there was no evidence that they had any major impact, positive or negative, on the broader health systems.     

Introduction of human papillomavirus vaccination in Nordic countries

Introduction

Cervical screening has helped decrease the incidence of cervical cancer, but the disease remains a burden for women. Human Papillomavirus (HPV) vaccination is now a promising tool for control of cervical cancer. Nordic countries (Denmark, Finland, Greenland, Iceland, Norway and Sweden) are relatively wealthy with predominantly publicly paid health care systems. The aim of this paper was to provide an update of the current status of introduction of HPV vaccine into the childhood vaccination programs in this region.

Methods

Data on cervical cancer, cervical screening programs, childhood immunization and HPV vaccination programs for Nordic countries were searched via PubMed and various organizations. We furthermore contacted selected experts for information.

Results

The incidence of cervical cancer is highest in Greenland (25 per 100,000, age standardized, World Standard Population, ASW) and lowest in Finland (4 per 100,000 ASW) and rates in the other Nordic countries vary between 7 and 11 per 100,000 ASW. Greenland and Denmark were first to introduce HPV vaccination, followed by Norway. Vaccination programs are underway in Sweden and Iceland, while Finland has just recently recommended introduction of vaccination. HPV vaccination has been intensively debated, in particular in Denmark and Norway.

Discussion

In Nordic countries with a moderate risk of cervical cancer and a publicly paid health care system, the introduction of HPV vaccination was a priority issue. Many players became active, from the general public to health professionals, special interest groups, and the vaccine manufacturers. These seemed to prioritize different health care needs and weighed differently the uncertainty about the long-term effects of the vaccine.

Conclusion

HPV vaccination posed a pressure on public health authorities to consider the evidence for and against it, and on politicians to weigh the wish for cervical cancer protection against other pertinent health issues.     

Influenza vaccination of health care workers in hospitals—A review of studies on attitudes and predictors

Introduction

Immunization guidelines from many countries recommend influenza vaccination of health care workers (HCW). However, influenza vaccination rates among HCW are universally low. To aid in designing effective immunization programs we reviewed the literature for studies reporting on (1) self-reported reasons of HCW regarding vaccination against influenza and (2) predictive factors for influenza vaccination in HCW.

Methods

We searched PUBMED for relevant publications from 1980 to 2008 with predetermined search strategies and applied pre-defined criteria for inclusion or exclusion. To be included in the review as a predictor study, a multivariate analysis must have been conducted.

Results

We included 25 studies relevant to self-reported reasons for rejecting or accepting vaccination. These studies identified two major reasons for lack of vaccine uptake by HCW: firstly, a wide range of misconceptions or lack of knowledge about influenza infection; and secondly, a lack of convenient access to vaccine. In contrast, among studies reporting on reasons for vaccination acceptance, all but two found that HCW stated self-protection was the most important reason. In the area of “predictive factors for influenza vaccination”, we included 13 studies. At least five of them identified the following three factors: previous receipt of influenza vaccine, belief in the vaccine's effectiveness, and older age.

Conclusion

Our findings indicate that if HCW get immunized against influenza, they do so primarily for their own benefit and not for the benefit to their patients. Misconceptions about influenza and influenza vaccine could be improved by education, and organizational barriers could be bridged with sustainable, structural changes to allow flexible and workplace vaccine delivery.     

Uptake of oral rotavirus vaccine and timeliness of routine immunization in Brazil's National Immunization Program

Introduction

In March, 2006, oral rotavirus vaccine was added to Brazil's infant immunization schedule with recommended upper age limits for initiating (by age 14 weeks) and completing (by age 24 weeks) the two-dose series to minimize age-specific risk of intussusception following rotavirus vaccination. Several years after introduction, estimated coverage with rotavirus vaccine (83%) was lower compared to coverage for other recommended childhood immunizations (≥94%).

Methods

We analyzed data from Brazil's national immunization program on uptake of oral rotavirus vaccine by geographic region and compared administrative coverage estimates for first and second doses of oral rotavirus vaccine (Rota1 and Rota2) with first and second doses of diphtheria-tetanus-pertussis-Haemophilus influenzae type b vaccine (DTP-Hib1 and DTP-Hib2). For 27 Brazilian cities, we compared differences between estimated rotavirus and DTP-Hib coverage in 2010 with delayed receipt of DTP-Hib vaccine among a cohort of children surveyed before rotavirus introduction.

Results

In 2010, infant vaccination coverage was 99.0% for DTP-Hib1 versus 95.2% for Rota1 (3.8% difference), and 98.4% for DTP-Hib2 versus 83.0% for Rota2 (15.4% difference), with substantial regional variation. Differences between DTP-Hib and rotavirus vaccination coverage in Brazilian cities correlated with delay in DTP-Hib vaccination among children surveyed. Age restrictions for initiating and completing the rotavirus vaccination series likely contributed to lower coverage with rotavirus vaccine in Brazil.

Conclusion

To maximize benefits of rotavirus vaccination, strategies are needed to improve timeliness of routine immunizations; monitoring rotavirus vaccine uptake and intussusception risk is needed to guide further recommendations for rotavirus vaccination.     

Educational interventions to increase HPV vaccination acceptance: A systematic review

Background

The Human papillomavirus (HPV) vaccine has been available for protection against HPV-associated cervical cancer and genital warts since 2006. Nonetheless, uptake has varied among countries and populations within countries. Studies have found that individuals’ knowledge and attitudes toward the vaccine are associated with immunization uptake. The purpose of the current review is to summarize and evaluate the evidence for educational interventions to increase HPV vaccination acceptance.

Methods

We searched the databases of PubMed and Web of Science for English-language articles describing educational interventions designed to improve HPV vaccination uptake, intention or attitude.

Results

We identified 33 studies of HPV vaccination educational interventions: 7 tested the effectiveness of interventions with parents, 8 with adolescents or young adults, and 18 compared the effectiveness of different message frames in an educational intervention among adolescents, young adults or their parents. Most studies involved populations with higher educational attainment and most interventions required participants to be literate. The minority of studies used the outcome of HPV vaccine uptake. Well-designed studies adequately powered to detect change in vaccine uptake were rare and generally did not demonstrate effectiveness of the tested intervention.

Conclusions

There is not strong evidence to recommend any specific educational intervention for wide-spread implementation. Future studies are required to determine the effectiveness of culturally-competent interventions reaching diverse populations.     

Interventions to improve adolescents' contraceptive behaviors in low- and middle-income countries: a review of the evidence base

Objective (s)

Many adolescents in developing countries have an unmet need for contraception, which can contribute to poor reproductive health outcomes. Recent literature reviews have not adequately captured effective contraceptive services and interventions for adolescents in low- and middle-income countries (LMICs). This study aims to identify and evaluate the existing evidence base on contraceptive services and interventions for adolescents in LMICs that report an impact on contraceptive behavior outcomes.

Study Design

Structured literature review of published and unpublished papers about contraceptive services and interventions for adolescents in LMICs that report an impact on contraceptive behavior outcomes.

Results

We identify common elements used by programs that measured an impact on adolescent contraceptive behaviors and summarize outcomes from 15 studies that met inclusion criteria. Effective programs generally combined numerous program approaches and addressed both user and service provision issues. Overall, few rigorous studies have been conducted in LMICs that measure contraceptive behaviors. Few interventions reach the young, the out of school and other vulnerable groups of adolescents.

Conclusion (s)

Though the evidence base is weak, there are promising foundations for adolescent contraceptive interventions in nearly every region of the world. We offer recommendations for programmers and identify gaps in the evidence base to guide future research.     

Provider perceptions of barriers and facilitators of HPV vaccination in a high-risk community

Background

Maximizing HPV vaccine uptake among those at highest risk for cervical cancer is critical. We explored healthcare provider perspectives on factors influencing HPV vaccination among adolescent girls in a community with high cervical cancer rates.

Methods

From March to May 2009, we conducted in-depth interviews with 21 medical staff providing care to adolescent girls at two clinics in Los Angeles, CA, serving a predominantly Hispanic population with high cervical cancer rates. Interviews were recorded and transcribed data were reviewed for coding and thematic content related to potential barriers and facilitators of HPV vaccination.

Results

Providers and medical staff overwhelmingly focused on parental beliefs as barriers to HPV vaccination. Perceived parental misconceptions acting as barriers included the belief that adolescents do not need vaccinations and that no-cost vaccine programs like Vaccines for Children are only available for younger children. Perceived parental concerns that the vaccine will promote sexual activity were prevalent, which prompted providers to frame HPV vaccine as a “routine” vaccine. However, the medical staff felt mothers with a friend or relative supportive of HPV vaccination were more likely to request the vaccine. The staff also noted that for Hispanic parents the “preferred” source of information is peers; if the “right people” in the community were supportive of HPV vaccine, parents were more willing to vaccinate. Other barriers included lack of immunization records among immigrant parents and a difficult-to-reach, mobile clientele.

Conclusions

Providers noted a number of barriers to HPV vaccination, including some perceived parental misconceptions that could be addressed with education about the need for adolescent vaccines and available free vaccine programs. Because community support appears particularly important to Hispanic parents, the use of promotoras – peer liaisons between health organizations and the community – may increase HPV vaccine uptake in this population.     

Cost-effectiveness and economic benefits of vaccines in low- and middle-income countries: A systematic review

Background

Public health interventions that prevent mortality and morbidity have greatly increased over the past decade. Immunization is one of these preventive interventions, with a potential to bring economic benefits beyond just health benefits. While vaccines are considered to be a cost-effective public health intervention, implementation has become increasingly challenging. As vaccine costs rise and competing priorities increase, economic evidence is likely to play an increasingly important role in vaccination decisions.

Methods

To assist policy decisions today and potential investments in the future, we provide a systematic review of the literature on the cost-effectiveness and economic benefits of vaccines in low- and middle-income countries from 2000 to 2010. The review identified 108 relevant articles from 51 countries spanning 23 vaccines from three major electronic databases (Pubmed, Embase and Econlit).

Results

Among the 44 articles that reported costs per disability-adjusted life year (DALY) averted, vaccines cost less than or equal to $100 per DALY averted in 23 articles (52%). Vaccines cost less than $500 per DALY averted in 34 articles (77%), and less than $1000 per DALY averted in 38 articles (86%) in one of the scenarios. 24 articles (22%) examined broad level economic benefits of vaccines such as greater future wage-earning capacity and cost savings from averting disease outbreaks. 60 articles (56%) gathered data from a primary source. There were little data on long-term and societal economic benefits such as morbidity-related productivity gains, averting catastrophic health expenditures, growth in gross domestic product (GDP), and economic implications of demographic changes resulting from vaccination.

Conclusions

This review documents the available evidence and shows that vaccination in low- and middle-income countries brings important economic benefits. The cost-effectiveness studies reviewed suggest to policy makers that vaccines are an efficient investment. This review further highlights key gaps in the available literature that would benefit from additional research, especially in the area of evaluating the broader economic benefits of vaccination in the developing world.     

Barriers to and facilitators of child influenza vaccine - perspectives from parents, teens, marketing and healthcare professionals

Background

The CDC recommends annual influenza vaccination for all children age 6 months and older, yet vaccination rates remain modest. Effective strategies to improve influenza vaccination for children are needed.

Methods

Eight focus groups with 91 parents, teens, pediatric healthcare staff and providers, and immunization and marketing experts were conducted, audiotaped, transcribed verbatim, and coded based on grounded theory.

Results

Three themes emerged: barriers, facilitators, and strategies. Barriers included fear, misinformation, and mistrust, with exacerbation of these barriers attributed to media messages. Many considered influenza vaccination unnecessary and inconvenient, but would accept vaccination if recipients or other family members were considered high risk, if recommended by their doctor or another trusted person, or if offered or mandated by the school. Access to better information regarding influenza disease burden and vaccine safety and efficacy were notable facilitators, as were prevention of the inconvenience of missing work or important events, and if the child requests to receive the vaccine. Marketing strategies included incentives, jingles, videos, wearable items, strategically-located information sheets or posters, and promotion by informed counselors. Practice-based strategies included staff buy-in, standing orders protocols, vaccination clinics, and educational videos. Teen-specific strategies included message delivery through schools, texting, internet, and social networking sites.

Conclusion

To improve influenza vaccination rates for children using practice-based interventions, participants suggested campaigns that provide better information regarding the vaccine, the disease and its implications, and convenient access to vaccination. Strategies targeting adolescents should use web-based social marketing technologies and campaigns based in schools.     

Medicaid reimbursement and the uptake of adolescent vaccines

Background

In light of low adolescent vaccination rates, state-level policies that could improve vaccine coverage should be evaluated. Approximately 1/3 of adolescents are eligible, primarily through Medicaid enrollment, to receive vaccines from state-administered Vaccines for Children (VFC) programs. We investigated whether Medicaid reimbursement, the scope of implementation of VFC programs (i.e. limited or universal purchase), and/or presence of school-based vaccine mandates were associated with adolescent vaccination levels.

Methods

We performed a cross-sectional analysis of state-level associations between these policies and 2009 National Immunization Survey-TEEN vaccination rates for tetanus-containing, meningococcal conjugate (MCV4), and among females only, human papillomavirus (HPV) vaccines.

Results

Medicaid reimbursement was not associated with vaccine coverage rates after adjusting for presence of vaccine-related school mandates, type of VFC program, proportion of adolescents attending preventive care visits, and state-specific distribution of insurance coverage. Participation in a more expansive VFC program (universal or universal-select) was significantly associated with HPV vaccine coverage, but not tetanus-containing vaccine or MCV4, among states that had mandates for any vaccines.

Conclusions

Our results suggest that, contrary to what has been shown for childhood vaccines, raising Medicaid reimbursement rates may not improve adolescent vaccine utilization. Instead, other policy changes may be more effective, such as expansion of VFC programs into universal purchase programs, further implementation of school-based vaccine mandates and efforts to raise preventive care visits among adolescents.     

The determinants of 2009 pandemic A/H1N1 influenza vaccination: a systematic review

Background

Pandemic A/H1N1 influenza vaccine coverage varied widely across countries. To understand the factors influencing pandemic influenza vaccination and to guide the development of successful vaccination programs for future influenza pandemics, we identified and summarized studies examining the determinants of vaccination during the 2009 influenza pandemic.

Methods

We performed a systematic literature review using the PubMED electronic database from June 2009 to February 2011. We included studies examining an association between a possible predictive variable and actual receipt of the pandemic A/H1N1 influenza vaccine. We excluded studies examining intention or willingness to receive the vaccine.

Results

Twenty-seven studies were identified from twelve countries. Pandemic influenza vaccine coverage varied from 4.8% to 92%. Coverage varied by population sub-group, country, and assessment method used. Most studies used questionnaires to estimate vaccine coverage, however seven (26%) used a vaccination registry. Factors that positively influenced pandemic influenza vaccination were: male sex, younger age, higher education, being a doctor, being in a priority group for which vaccination was recommended, receiving a prior seasonal influenza vaccination, believing the vaccine to be safe and/or effective, and obtaining information from official medical sources.

Conclusions

Vaccine coverage during the pandemic varied widely across countries and population sub-groups. We identified some consistent determinants of this variation that can be targeted to increase vaccination during future influenza pandemics.     

Decision support in vaccination policies

Background

Looking across boarders reveals that the national immunization programs of various countries differ in their vaccination schedules and decisions regarding the implementation and funding of new vaccines. The aim of this review is to identify decision aids and crucial criteria for a rational decision-making process on vaccine introduction and to develop a theoretical framework for decision-making based on available literature.

Methods

Systematic literature search supplemented by hand-search.

Results

We identified five published decision aids for vaccine introduction and program planning in industrialized countries. Their comparison revealed an overall similarity with some differences in the approach as well as criteria. Burden of disease and vaccine characteristics play a key role in all decision aids, but authors vary in their views on the significance of cost-effectiveness analyses. Other relevant factors that should be considered before vaccine introduction are discussed to highly differing extents. These factors include the immunization program itself as well as its conformity with other programs, its feasibility, acceptability, and equity, as well as ethical, legal and political considerations. Assuming that the most comprehensive framework possible will not provide a feasible tool for decision-makers, we suggest a stepwise procedure.

Conclusions

Though even the best rational approach and most comprehensive evaluation is limited by remaining uncertainties, frameworks provide at least a structured approach to evaluate the various aspects of vaccine implementation decision-making. This process is essential in making consistently sound decisions and will facilitate the public's confidence in the decision and its realization.     

At what sites are parents willing to have their 11 through 14-year-old adolescents immunized?

Introduction

Parental preferences of alternative immunization sites for adolescents must be evaluated to determine optimal delivery strategies.

Methods

Analyses were performed on data from middle-school parent questionnaires in low income areas.

Results

1838 questionnaires were returned; 86.5% of the participants were Hispanic, 65% spoke primarily Spanish at home. Among those with a medical home, 32% had the last immunization at an alternative location. When checking all that apply, 65% of parents selected the medical home as a desirable location for immunization; 41% selected a school-based program.

Conclusions

Despite lack of exposure to school-based immunization programs, school-based programs are a desirable immunization site among middle-school parents.     

Vaccination coverage in Haiti: results from the 2009 national survey

Introduction

Since 1977, vaccinations to protect against tuberculosis, diphtheria, tetanus, pertussis, polio, and measles (and rubella since 2009) have been offered to children in Haiti through the routine immunization program. From April to July 2009, a national vaccination coverage survey was conducted to assess the success of the routine immunization program at reaching children in Haiti.

Methods

A multi-stage cluster survey was conducted using a modified WHO method for household sampling. A standardized questionnaire was administered to collect vaccination histories, demographic information, and reasons for under-vaccination of children aged 12–23 months. A child who received the eight recommended routine vaccinations was considered fully vaccinated. The routine vaccination schedule was used to define valid doses and estimate the percentage of children vaccinated on time.

Results

Among 1345 children surveyed, 40.4% (95% CI: 36.6–44.2) of the 840 children with vaccination cards had received all eight recommended vaccinations. Coverage was highest for the Bacille Calmette–Guérin vaccine (87.3%), the first doses of the diphtheria–tetanus–pertussis vaccine (92.0%), and oral poliovirus vaccine (93.4%) and lowest for measles vaccine (46.9%). Timely vaccination rates were lower. Assuming similar coverage for the 505 children without cards, coverage with the complete vaccination series among all surveyed children 31.9%. Reasons for under-vaccination included not having enough time to reach the vaccination location (24.8%), having a child who was ill (13.8%), and not knowing when, or forgetting, to go for vaccination (12.8%).

Conclusions and recommendations

Coverage for early-infant vaccines was high; however, most children did not complete the full vaccination series, and many children received vaccinations later than recommended. Efforts to improve the immunization program should include increasing the frequency of outreach services, training for vaccination staff to minimize missed opportunities, and better communicating the timing of vaccinations to encourage caregivers to bring their children for vaccinations at the recommended age. Efforts to promote the benefits of vaccination and card retention are also needed.     

Modeling the potential impact of vaccination on the epidemiology of congenital cytomegalovirus infection

Background

Understanding the potential for vaccination to change cytomegalovirus (CMV) epidemiology is important for developing CMV vaccines and designing clinical trials.

Methods

We constructed a deterministic, age-specific and time-dependent mathematical model of pathogen transmission, parameterized using CMV seroprevalence from the United States and Brazil, to predict the impact of vaccination on congenital CMV infection.

Findings

Concurrent vaccination of young children and adolescents would result in the greatest reductions in congenital CMV infections in populations with moderate and high baseline maternal seroprevalence. Such a vaccination strategy, assuming 70% vaccine efficacy, 90% coverage and 5-year duration of protection, could ultimately prevent 30–50% of congenital CMV infections. At equilibrium, this strategy could result in a 30% reduction in congenital CMV infections due to primary maternal infection in the United States but a 3% increase in Brazil. The potential for an increase in congenital CMV infections due to primary maternal infections in Brazil was not predicted with use of a vaccine that confers protection for greater than 5 years.

Interpretation

Modeling suggests that vaccination strategies that include young children will result in greater declines in congenital CMV infection than those restricted to adolescents or women of reproductive age. Our study highlights the critical need for better understanding of the relative contribution of type of maternal infection to congenital CMV infection and disease, the main focus of vaccine prevention.     

The impact of new vaccine introduction on the coverage of existing vaccines: A cross-national,multivariable analysis

Background

A surge of new and underutilized vaccine introductions into national immunization programmes has called into question the effect of new vaccine introduction on immunization and health systems. In particular, countries deciding whether to introduce a new or underutilized vaccine into their routine immunization programme may query possible effects on the delivery and coverage of existing vaccines. Using coverage of diphtheria–tetanus–pertussis (DTP) vaccine as a proxy for immunization system performance, this study aims to test whether new vaccine introduction into national immunization programs was associated with changes in coverage of three doses of DTP vaccine among infants.

Methods and findings

DTP3 vaccine coverage was analyzed in 187 countries during 1999–2009 using multivariable cross-national mixed-effect longitudinal models. Controlling for other possible determinants of DTP3 coverage at the national level these models found minimal association between the introduction of Hepatitis-, Haemophilus influenzae type b-, and rotavirus-containing vaccines and DTP3 coverage. Instead, frequent and sometimes large fluctuations in coverage are associated with other development and health systems variables, including the presence of armed conflict, coverage of antenatal care services, infant mortality, the percent of health expenditures that are private and total health expenditures per capita.

Conclusions

Introductions of new vaccines did not affect national coverage of DTP3 vaccine in the countries studied. Introductions of other new vaccines and multiple vaccine introductions should be monitored for immunization and health systems impacts.     

Association of vaccine-related attitudes and beliefs between parents and health care providers

Objectives

Health care providers influence parental vaccination decisions. Over 90% of parents report receiving vaccine information from their child's health care provider. The majority of parents of vaccinated children and children exempt from school immunization requirements report their child's primary provider is a good source for vaccine information. The role of health care providers in influencing parents who refuse vaccines has not been fully explored. The objective of the study was to determine the association between vaccine-related attitudes and beliefs of health care providers and parents.

Methods

We surveyed parents and primary care providers of vaccinated and unvaccinated school age children in four states in 2002–2003 and 2005. We measured key immunization beliefs including perceived risks and benefits of vaccination. Odds ratios for associations between parental and provider responses were calculated using logistic regression.

Results

Surveys were completed by 1367 parents (56.1% response rate) and 551 providers (84.3% response rate). Parents with high confidence in vaccine safety were more likely to have providers with similar beliefs, however viewpoints regarding disease susceptibility and severity and vaccine efficacy were not associated. Parents whose providers believed that children get more immunizations than are good for them had 4.6 higher odds of holding that same belief compared to parents whose providers did not have that belief.

Conclusions

The beliefs of children's health care providers and parents, including those regarding vaccine safety, are similar. Provider beliefs may contribute to parental decisions to accept, delay or forgo vaccinations. Parents may selectively choose providers who have similar beliefs to their own.     

Economic impact of the introduction of an acellular pertussis vaccine in Canada: A 6-year analysis

Background

Between July 1997 and April 1998, Canadian public health agencies switched from the whole cell vaccine to the acellular vaccine for pertussis immunization. The acellular vaccine provided better efficacy and fewer adverse events than the whole cell vaccine did.

Objective

To determine the economic impact of replacing the whole cell vaccine with an acellular vaccine in Canada.

Methods

A decision analytic model was developed comparing costs and outcomes of pertussis vaccination for Canadian children born in the years 1991–2004. Effectiveness was measured as number of avoided pertussis cases as well as the number of avoided hospital admissions. Incremental costs per avoided pertussis case and per avoided hospital admission were calculated for Ministry of Health (MoH) and societal (SOC) perspectives. Various one-way sensitivity analyses as well as a Monte Carlo simulation were performed by varying key model parameters.

Results

The switch in immunization programs resulted in an incremental cost to the MoH of CAD $108 per pertussis case avoided (CAD $0.96 per child-year). From the SOC perspective, there was a savings of CAD $184 per pertussis case avoided (CAD $0.13 per child-year). The one-way sensitivity analyses provided incremental cost-effective ratios (ICERs) ranging from an incremental cost of CAD $1034 per avoided pertussis case from the MoH perspective to a saving of CAD $1583 per avoided case from the SOC perspective. The Monte Carlo simulation confirmed the robustness of these results.

Conclusions

Pertussis vaccination with AcE was cost-saving from the societal perspective and cost-effective from the Ministry of Health perspective.