Are immunosuppressive medications associated with decreased responses to routine immunizations? A systematic review

Background

Long-term immunosuppressive medications are being used more commonly for a variety of medical conditions, including immune-mediated diseases and organ transplantation. While these medications are often necessary, they are associated with an increased risk of serious infections. Vaccination may be a way to prevent a variety of infections but vaccine responses among patients receiving immunosuppressive therapies have been variable.

Purpose

To systematically review the literature describing immune responses among patients on immunosuppressive therapies to vaccinations including influenza, pneumococcal, meningococcal, hepatitis A and B, tetanus toxoid, pertussis, varicella, and zoster.

Data sources

English language citations in the MEDLINE and EMBASE databases from 1985 to 2010.

Study selection

Two reviewers independently screened titles and abstracts to identify prospective, controlled studies reporting pre- and post-vaccination titers of recommended vaccines in patients receiving long-term immunosuppressive therapies for full-text review.

Data extraction

Three reviewers independently assessed study characteristics including treatment regimens and pre- and post-vaccination titers.

Data synthesis

Of the 972 identified titles, fifteen met inclusion criteria. Ten studies assessed the effects of immunosuppressive medications on responses to influenza vaccine, four studies investigated responses following pneumococcal vaccination, and one study assessed both influenza and pneumococcal vaccination. Five of the studies that evaluated influenza vaccination showed partially diminished responses among individuals receiving immunosuppressive therapies, while one of the pneumococcal vaccine studies showed significantly decreased responses following vaccination. Patients treated with more than one immunosuppressive medication were the least likely to respond to vaccination.

Limitations

The heterogeneity of reported outcomes limits generalizeability.

Conclusions

Immunosuppressive therapy, particularly combination regimens, may blunt response to influenza and pneumococcal vaccinations. To ensure the best chance of response, immunizations should be administered prior to initiation of immunosuppressive medications whenever possible.     

Circulating pneumococcal specific plasma and memory B cells in the elderly two years after pneumococcal conjugate versus polysaccharide vaccination

Background

Polysaccharide conjugate vaccines prime for lasting memory responses in children and young adults. The potential value of these vaccines in the elderly is unclear.

Methods

We compared the frequency of circulating pneumococcal capsular polysaccharide (PPS) specific IgG, IgA and IgM plasma and memory cells by cultured ELISpot and supernatant screening two years after vaccination with the 7-valent pneumococcal conjugate vaccine (7vCRM) and/or the 23-valent pneumococcal polysaccharide vaccine (PPV) in 252 adults aged 50–80 years. Some individuals received a six-month boost with 7vCRM or PPV. PPS specific IgG memory detected two years post-primary vaccination was correlated with published matched serum IgG concentration pre- and up to one year post-primary vaccination.

Results

There was no difference by vaccine schedule in the quantity of plasma or memory cells detected. The concentration of in vitro PPS IgG produced by memory B cells isolated two years post-vaccination correlated with pre-vaccination serum IgG concentration and not with D28 post-vaccination responses regardless of vaccination schedule.

Conclusions

This study shows that circulating memory B cells numbers two years following immunisation with 7vCRM or PPV are best predicted by pre-vaccination serotype specific serum antibody concentration and not early post-vaccination serum antibody responses.     

Cost-effectiveness of pneumococcal conjugate vaccination in immunocompromised adults

Objective

Pneumococcal disease is a significant problem in immunocompromised persons, particularly in HIV-infected individuals. The CDC recently updated pneumococcal vaccination recommendations for immunocompromised adults, adding the 13-valent pneumococcal conjugate vaccine (PCV13) to the previously recommended 23-valent pneumococcal polysaccharide vaccine (PPSV23). This analysis estimates the cost-effectiveness of pneumococcal vaccination strategies in HIV-infected individuals and in the broader immunocompromised adult group.

Design

Markov model-based cost-effectiveness analysis.

Methods

The model considered immunocompromised persons aged 19–64 years and accounted for childhood PCV13 herd immunity; in a separate analysis, an HIV-infected subgroup was considered. PCV13 effectiveness was estimated by an expert panel; PPSV23 protection was modeled relative to PCV13 effectiveness. We assumed that both vaccines prevented invasive pneumococcal disease, but only PCV13 prevented nonbacteremic pneumonia.

Results

In all immunocompromised individuals, a single PCV13 cost $70,937 per quality adjusted life year (QALY) gained compared to no vaccination; current recommendations cost $136,724/QALY. In HIV patients, with a longer life expectancy (22.5 years), current recommendations cost $89,391/QALY compared to a single PCV13. Results were sensitive to variation of life expectancy and vaccine effectiveness. The prior recommendation was not favored in any scenario.

Conclusions

One dose of PCV13 is more cost-effective for immunocompromised individuals than previous vaccination recommendations and may be more economically reasonable than current recommendations, depending on life expectancy and vaccine effectiveness in the immunocompromised.     

Mothers’ Preferences and Willingness to Pay for Human Papillomavirus Vaccination for Their Daughters: A Discrete Choice Experiment in Hong Kong

Objectives

To determine the preference of mothers in Hong Kong and their willingness to pay (WTP) for human papillomavirus (HPV) vaccination for their daughters.

Cost-effectiveness of pneumococcal conjugate vaccines of 7, 10, and 13 valences in Colombian children

Background

Currently there are three pneumococcal conjugate vaccines with different coverage of serotypes for use in children under one year. We evaluate the cost-effectiveness of the introduction of pneumococcal conjugate vaccines of 7, 10, and 13 valences in the Colombian EPI.

Methods

A Markov model, which followed a cohort of children under one year to life expectancy, was developed. Parameters of occurrence and care costs were based on data from National Health System and literature review. PCV-7 is a dominated strategy. PCV-10 and PCV-13 were each compared to no vaccination or PCV-10 vaccination, respectively. A 2 + 1 schedule and a vaccination price of US$ 14.00, US$ 14.85 and US$ 16.34 per dose were assumed in the base case for PCV-7, -10, and PCV-13 vaccines.

Results

Introduction of PCV-13 rather than PCV-10 increases the number of life years gained (LYG). From the societal perspective, in the ‘competing choice’ framework cost per LYG was US$ 1837 with PCV-10 and US$ 9514 with PCV-13, while PCV-7 is a dominated strategy. The ICER of PCV-13 is above the per capita Gross Domestic Product. Incremental cost-effectiveness ratios (ICERs) were influenced mainly by effectiveness against radiologically-confirmed pneumonia and AOM, vaccine price, and discount rate.

Conclusion

Routine vaccination against Streptococcus pneumoniae in Colombia would be cost-effective with PCV-10, with ICER below the per-capita GDP, but its inclusion requires evaluating the budget impact. PCV-13 would prevent more disease and deaths with a higher LYG, but PCV-10 would save more cost to the healthcare system due its higher impact in the prevention of AOM. There is limitation in the clinical evidence of both strategies.     

Projected health impact and cost-effectiveness of rotavirus vaccination among children <5 years of age in China

Introduction

Two rotavirus vaccines have been licensed globally since 2006. In China, only a lamb rotavirus vaccine is licensed and several new rotavirus vaccines are in development. Data regarding the projected health impact and cost-effectiveness of vaccination of children in China against rotavirus will assist policy makers in developing recommendations for vaccination.

Methods

Using a Microsoft Excel model, we compared the national health and economic burden of rotavirus disease in China with and without a vaccination program. Model inputs included 2007 data on burden and cost of rotavirus outcomes (deaths, hospitalizations, outpatient visits), projected vaccine efficacy, coverage, and cost. Cost-effectiveness was measured in US dollars per disability-adjusted life-year (DALY) and US dollars per life saved.

Results

A 2-dose rotavirus vaccination program could annually avert 3013 (62%) deaths, 194,794 (59%) hospitalizations and 1,333,356 (51%) outpatient visits associated with rotavirus disease in China. The medical break-even price of the vaccine is $1.19 per dose. From a societal perspective, a vaccination program would be highly cost-effective in China at the vaccine price of $2.50 to $5 per dose, and be cost-effective at the price of $10 to $20 per dose.

Conclusions

A national rotavirus vaccination program could be a cost-effective measure to effectively reduce deaths, hospitalizations, and outpatient visits due to rotavirus disease in China.     

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.     

Parental and societal values for the risks and benefits of childhood combination vaccines

Background

New combination vaccines reduce the number of injections needed for immunization. However, possible drawbacks include higher prices, extra doses of vaccine antigens and increased minor adverse events. Our objective was to measure parental and societal values for attributes of childhood combination vaccines.

Methods

We conducted a discrete choice experiment using an online survey of adults administered by Knowledge Networks. Values were measured for attributes of combination vaccines for a hypothetical child aged 6 months: (1) number of injections, (2) extra dose of hepatitis B vaccine, (3) 20% higher chance of fever, (4) community-level immunization coverage of 2-year-olds of 90% or 80%, and (5) cost per visit. Logistic regression with generalized estimating equations was used to analyze the value of different attributes and generate a marginal willingness-to-pay for a change in attribute level.

Results

The response rate was 64% (N = 558). Most respondents were parents (63%) and most respondents agreed that combination vaccines were safe (77%). Respondents were willing to pay $7.68 to avoid an injection (compared to $9.94 when looking at parents only). However, respondents were willing to pay $41.57 to avoid higher risk of fever after one set of immunizations (10% versus 30%) and $65.42 for higher immunization coverage rates. These results were very similar for parents only. There was no significant preference to avoid an extra dose of hepatitis B vaccine.

Conclusions

Respondents were willing to pay larger amounts to avoid increased risk of minor adverse events and to increase community-level immunization coverage than to avoid injections. These values should be taken into account when determining the risks and benefits of combination vaccines.     

Immunogenicity and safety of a 13-valent pneumococcal conjugate vaccine compared to a 23-valent pneumococcal polysaccharide vaccine in pneumococcal vaccine-naive adults

Background

Streptococcus pneumoniae is a major cause of morbidity and mortality among adults 50 years of age and older in the United States. Pneumococcal conjugate vaccines are efficacious against pneumococcal disease in children and may also offer advantages in adults.

Methods

We performed a randomized, modified double-blind trial that compared a single dose of 13-valent pneumococcal conjugate vaccine (PCV13) with 23-valent pneumococcal polysaccharide vaccine (PPSV23) in 831 pneumococcal vaccine naive adults 60–64 years of age. An additional group of 403 adults 50–59 years of age received open-label PCV13. Anti-pneumococcal opsonophagocytic activity (OPA) titers were measured at baseline, and at 1 month and 1 year after vaccination.

Results

In the randomized trial, the month 1 post-vaccination OPA geometric mean titers in the PCV13 group were statistically significantly higher than in the PPSV23 group for 8 of the 12 serotypes common to both vaccines and for serotype 6A, a serotype unique to PCV13, and were comparable for the other 4 common serotypes. The immune response to PCV13 was generally greater in adults 50–59 years of age compared to adults 60–64 years of age. OPA titers declined from 1 month to 1 year after PCV13 administration but remained higher than pre-vaccination baseline titers.

Conclusions

PCV13 induces a greater functional immune response than PPSV23 for the majority of serotypes covered by PCV13, suggesting that PCV13 could offer immunological advantages over PPSV23 for prevention of vaccine-type pneumococcal infection.     

Carrier priming or suppression: Understanding carrier priming enhancement of anti-polysaccharide antibody response to conjugate vaccines

Introduction

With the availability of newer conjugate vaccines, immunization schedules have become increasingly complex due to the potential for unpredictable immunologic interference such as ‘carrier priming’ and ‘carrier induced epitopic suppression’. Carrier priming refers to an augmented antibody response to a carbohydrate portion of a glycoconjugate vaccine in an individual previously primed with the carrier protein. This review aims to provide a critical evaluation of the available data on carrier priming (and suppression) and conceptualize ways by which this phenomenon can be utilized to strengthen vaccination schedules.

Methods

We conducted this literature review by searching well-known databases to date to identify relevant studies, then extracted and synthesized the data on carrier priming of widely used conjugate polysaccharide vaccines, such as, pneumococcal conjugate vaccine (PCV), meningococcal conjugate vaccine (MenCV) and Haemophilus influenzae type b conjugate vaccines (HibV).

Results

We found evidence of carrier priming with some conjugate vaccines, particularly HibV and PCV, in both animal and human models but controversy surrounds MenCV. This has implications for the immunogenicity of conjugate polysaccharide vaccines following the administration of tetanus-toxoid or diphtheria-toxoid containing vaccine (such as DTP).

Conclusion

Available evidence supports a promising role for carrier priming in terms of maximizing the immunogenicity of conjugate vaccines and enhancing immunization schedule by making it more efficient and cost effective.     

Vaccinal issues between Belgian and French travelers

Introduction

The yellow-fever vaccination center of the Tourcoing Hospital (France) has been accessible to Belgian travelers since its opening in 1994.

Method

The authors reported the specificities of these consultations during the year 2010, by retrospectively analyzing electronic medical records.

Results

Some medical issues encountered during the consultation were due to differences in vaccination schedules: for the polio vaccine, since the last dose is administered between 5 and 7 years of age in Belgium; and for the measles vaccine since a late two-dose schedule (second dose between 12 and 13 years of age) is recommended in this country. Moreover, some specific vaccines are available only in Belgium: a diphtheria-tetanus bivalent vaccine, and a live attenuated oral typhoid vaccine.

Discussion

The specificities of the Belgian border traveler consultation in our French yellow-fever center are due to a difference in European vaccination schedules; the physician must be aware of these.

Conclusion

The physician has to propose updates on vaccination schedules, and be aware of yellow-fever vaccine compatibility with vaccines recently administered in Belgium.     

How influenza vaccination policy may affect vaccine logistics

Background

When policymakers make decision about the target populations and timing of influenza vaccination, they may not consider the impact on the vaccine supply chains, which may in turn affect vaccine availability.

Purpose

Our goal is to explore the effects on the Thailand vaccine supply chain of introducing influenza vaccines and varying the target populations and immunization time-frames.

Methods

We Utilized our custom-designed software HERMES (Highly Extensible Resource for Modeling Supply Chains), we developed a detailed, computational discrete-event simulation model of the Thailand's National Immunization Program (NIP) supply chain in Trang Province, Thailand. A suite of experiments simulated introducing influenza vaccines for different target populations and over different time-frames prior to and during the annual influenza season.

Results

Introducing influenza vaccines creates bottlenecks that reduce the availability of both influenza vaccines as well as the other NIP vaccines, with provincial to district transport capacity being the primary constraint. Even covering only 25% of the Advisory Committee on Immunization Practice-recommended population while administering the vaccine over six months hinders overall vaccine availability so that only 62% of arriving patients can receive vaccines. Increasing the target population from 25% to 100% progressively worsens these bottlenecks, while increasing influenza vaccination time-frame from 1 to 6 months decreases these bottlenecks.

Conclusion

Since the choice of target populations for influenza vaccination and the time-frame to deliver this vaccine can substantially affect the flow of all vaccines, policy-makers may want to consider supply chain effects when choosing target populations for a vaccine.     

The acceptance and willingness to pay (WTP) for hypothetical dengue vaccine in Penang,Malaysia: a contingent valuation study

Background

Malaysia has been experiencing an escalation in dengue cases since the past 5 years. As the dengue vaccine pipeline continues to develop steadily with strong public interests, this study had been sought to elicit the acceptance and the willingness to pay (WTP) for hypothetical dengue vaccine in Malaysia.

Methods

This study adopted the cross-sectional, contingent valuation study that involved 400 respondents in Penang, Malaysia. The double-bounded dichotomous choice via bidding game approach was employed to elicit the WTP value for two hypothetical 3-doses dengue vaccines (Vaccines A and B with 5- and 10-years’ protection, respectively against dengue). A univariate logistic regression model was employed to assess the key determinants of vaccine acceptance, while the mean WTP value and its associated factors were measured by using the parametric two-part model (TPM).

Results

Dengue vaccine appeared to be highly acceptable (88.4%) among the population in Penang, Malaysia. Respondents who were of Chinese ethnicity (OR 0.36, p?=?0.017), with higher dengue knowledge score (OR 1.43, p?=?0.016), and higher vaccination attitude score (OR 1.91, p?<?0.001) were more likely to accept the vaccine. The first step logit estimation from TPM displayed that pensioners (OR 2.37, p?=?0.036), respondents who were self-employed or working in the private sector (OR 1.21, p?=?0.002), respondents with higher education level (OR 2.09–3.29, p?<?0.05), and those who accepted the vaccine (OR 3.23, p?=?0.001) were more likely to pay for the vaccine. The adjusted mean WTP value for the vaccine was MYR39.21 (USD9.45) per dose. Next, the second-stage regression from TPM revealed the key factors that significantly affected the WTP value, which were composed of age, gender, occupation, household income, dengue prevention practice, and protection duration of the vaccine. The pensioners and those with better dengue prevention practice were willing to pay more for the vaccines. Additionally, all the respondents elicited a higher WTP amount toward the vaccine with longer protection duration (Vaccine B).

Conclusion

Strong acceptance toward dengue vaccine reflects the high value of the vaccine in Malaysia. The WTP estimates offer quantification of the private benefit in reducing occurrences of the disease. Besides, the people’s preferences-based WTP value for the vaccine tends to complement scientific decision-making and prioritization in the management of dengue in the country.

     

Influence of initial vaccination with 13-valent pneumococcal conjugate vaccine or 23-valent pneumococcal polysaccharide vaccine on anti-pneumococcal responses following subsequent pneumococcal vaccination in adults 50 years and older

Background

Unlike free polysaccharide vaccines, pneumococcal polysaccharide conjugate vaccines (PCVs) induce a T cell-dependent immune response and have the potential to provide an extended duration of protection with repeated vaccinations.

Methods

This was an extension of a previous study in pneumococcal vaccine-naïve adults aged 50–64 years in which adults 60–64 years of age were given 13-valent PCV (PCV13) or 23-valent pneumococcal polysaccharide vaccine (PPSV23) and adults aged 50–59 were given PCV13. In this follow up study conducted about 4 years later, the 60–64 year olds initially given PCV13 received PCV13 or PPSV23, and those initially given PPSV23 received another PPSV23. All adults aged 50–59 years were re-vaccinated with PCV13. Anti-pneumococcal opsonophagocytic activity (OPA) titers were measured before and 1 month after vaccination.

Results

A second PCV13 given about 4 years after a first vaccination induced OPA titers that were significantly higher than those following the initial vaccination for 7 of 13 serotypes in the older group, and 6 of 13 serotypes in the younger group, and responses to the remaining serotypes were largely non-inferior. In contrast, OPA titers following revaccination with PPSV23 were statistically significantly lower for 9 of the 13 serotypes, and non-inferior for the remaining serotypes, when compared to the responses to the first PPSV23. OPA titers in the older adults who received PPSV23 after initial PCV13 were significantly higher than those following a first PPSV23 for 10 of the 13 serotypes.

Conclusion

In adults 50 to 64 years of age, initial vaccination with PCV13 establishes an immune state that results in recall anti-pneumococcal responses upon subsequent vaccination with either conjugated or free polysaccharide vaccine. In contrast, initial vaccination with PPSV23 results in an immune state in which subsequent PPSV23 administration yields generally lower responses compared with the initial responses.     

Costs of vaccine delivery in the Gambia before and after,pentavalent and pneumococcal conjugate vaccine introductions

Background

The Gambia introduced seven-valent pneumococcal conjugate vaccine (PCV) in August 2009 and switched to 13-valent PCV in April 2011. In April 2009 monovalent hepatitis B and combined Diphtheria–Tetanus–Pertussis and Haemophilus influenzae type b vaccines were transitioned to a combined pentavalent vaccine. The current schedule offers three doses of PCV and pentavalent, and continues to give children monovalent hepatitis B vaccine at birth. We estimated the overall costs of the Gambian immunisation programme and the incremental costs of introducing pentavalent and the seven-valent PCV.

Methods

Twenty health facilities out of a total of 56 were surveyed. Data collected included number of vaccine doses delivered, staff time spent on vaccine delivery, distance travelled to collect vaccines, and cold chain expansion due to new vaccine introduction. National level data were collected from key informant interviews. Annualised costs were calculated in 2009 US$.

Results

With a PCV price of US$7 per dose, the incremental costs of introducing PCV was US$1.6 million, equivalent to US$25 per fully immunised child, with systems costs accounting for US$1.90. The switch to pentavalent vaccine resulted in cost savings of US$0.45 per fully immunised child. Total annual costs increased by 45% after the introduction of the new vaccines, amounting to US$ 3.0 million, or US$45 per fully immunised child.

Conclusion

Vaccine prices were the most important determinant of total incremental costs and cold chain expansion the biggest cost component of systems costs.     

The Impact of Socio-Economic Determinants on the Vaccination Rates with Rotavirus and Human Papiloma Virus Vaccine

Background

Socio-economic inequalities may have an impact on the uptake of selfpaid vaccines. The aim of the study was to identify the effect of some socio economic determinants on vaccination rates with self-paid human papilloma virus (HPV) and rotavirus (RV) vaccines.

Methods

Vaccination coverage data, available in electronic database cepljenje.net (administered by the National Institute of Public Health), were collected at administrative unit level. The socio-economic determinants (the average gross pay in euros, the unemployment rate, the educational and households structure, the population density, the number of inhabitants, the number of children aged from 0 to 4, the number of women aged from 15 to 30) were extracted from Statistical Office of the Republic of Slovenia web page. The strength of the correlation between socioeconomic variables and self-paid HPV and RV vaccination rates was determined.

Results

Rotavirus vaccination rates show a slight negative correlation with the number of residents per administrative unit (ρ=−0.29, p=0.04), and no correlation with other socio-economic variables. Likewise, no correlation has been found between HPV vaccination rates and the selected socio-economic variables.

Conclusion

Ecological study did not reveal any correlations between socio economic variables and vaccination rates with RV and HPV self-paid vaccines on administrative unit level.     

The cost-effectiveness of a 13-valent pneumococcal conjugate vaccination for infants in England

Background

In the immunisation schedule in England and Wales, the 7-valent pneumococcal conjugate vaccine (PCV-7) was replaced by the 13-valent vaccine (PCV-13) in April 2010 after having been used since September 2006. The introduction of PCV-7 was informed by a cost effectiveness analysis using an infectious disease model which projected herd immunity and serotype replacement effects based on the post-vaccine experience in the United States at that time.

Aim

To investigate the cost effectiveness of the introduction of PCV-13.

Method

Invasive disease incidence following vaccination was projected from a dynamic infectious disease model, and combined with serotype specific disease outcomes obtained from a large hospital dataset linked to laboratory confirmation of invasive pneumococcal disease. The economic impact of replacing PCV-7 with PCV-13 was compared to stopping the use of pneumococcal conjugate vaccination altogether.

Results

Discontinuing PCV-7 would lead to a projected increase in invasive pneumococcal disease, costs and loss of quality of life compared to the introduction of PCV-13. However under base case assumptions (assuming no impact on non-invasive disease, maximal competition between vaccine and non-vaccine types, time horizon of 30 years, vaccine price of £49.60 a dose + £7.50 administration costs and discounting of costs and benefits at 3.5%) the introduction of PCV-13 is only borderline cost effective compared to a scenario of discontinuing of PCV-7. The intervention becomes more cost-effective when projected impact of non-invasive disease is included or the discount factor for benefits is reduced to 1.5%.

Conclusion

To our knowledge this is the first evaluation of a transition from PCV-7 to PCV-13 based on a dynamic model. The cost-effectiveness of such a policy change depends on a number of crucial assumptions for which evidence is limited, particularly the impact of PCV-13 on non-invasive disease.     

Risk factors of underutilization of childhood immunizations in ultraorthodox Jewish communities in Israel despite high access to health care services

Background

The risk factors of underutilization of childhood vaccines in populations with high access to health services are not fully understood.

Objectives

To determine vaccination coverage and factors associated with underutilization of childhood vaccines in a population with sub-optimal vaccination compliance, despite a high health care access.

Methods

The study was conducted among 430 children from ultraorthodox Jewish communities in the Bnei Brak city and Jerusalem district. Data on immunization status, socio-demographic factors and on parents’ attitudes regarding vaccines were obtained from medical records and through parents’ interviews.

Results

The proportion of fully vaccinated children was 65% in 2- to 5-year-old ultraorthodox children from Jerusalem district, and 86% in 2.5-year-old children from Bnei Brak city. The factors that were significantly associated with vaccines underutilization in Bnei Brak were having >6 siblings, maternal academic education, parental religious beliefs against vaccination, perceived risk of vaccine preventable diseases as low, and mistrust in the Ministry of Health (MOH). Similarly, in Jerusalem, religious beliefs against vaccination, and the perceived low risk of vaccine preventable diseases significantly increased the likelihood of under-immunization, while having a complementary health insurance was inversely related with vaccines underutilization.

Conclusions

The risk factors of under-immunization are in part modifiable, by means of health education on the risks of vaccine preventable diseases and by improving the trust in the MOH. The leaders of the ultraorthodox communities could play an important role in such interventions.