Community,parental and adolescent awareness and knowledge of meningococcal disease

Objective

To assess knowledge of invasive meningococcal disease (IMD) and concern about the disease in the South Australian Community including adolescents, adults, parents and non-parents.

Methods

This cross-sectional study was conducted by face to face interviews in South Australia in 2012. Participants were scored on their knowledge and concern about IMD. Univariate and multivariate regression analyses were performed with the survey data weighted by age and gender in accordance with 2011 Census data.

Results

Of 5200 households randomly selected and stratified by metropolitan or rural location, 3055 participants were interviewed with a response rate of 60.3%. The majority were Australian born (74.2%, n = 2267) with 31.8% (n = 972) of those interviewed being parents, and 15.9% (n = 487) adolescents (15–24 years). Almost a quarter of participants (23.5%, n = 717) do not know what meningococcal disease is, with 9.1% (n = 278) believing incorrectly that IMD is a viral infection. 36.6% (n = 1114) had low overall knowledge of IMD. Adolescents (p < 0.050), non-Australian born (p < 0.001), low educational attainment (p = 0.019), low household income (p = 0.011), low/medium socio-economic status (p < 0.050) or living in a metropolitan area (p = 0.006) were more likely to have lower overall knowledge of IMD. Participants who were not parents (p < 0.001), male gender (p < 0.001), single (p < 0.001), highly educated (p = 0.022) or had high household income (p = 0.015), had lower concern about IMD.

Conclusion

Large community knowledge gaps for IMD were observed, particularly amongst adolescents and adults with low educational attainment and low socio-economic status. Improving community knowledge of IMD could help ensure optimal uptake of a new meningococcal vaccine. Our study results can help guide development of community tailored immunisation education programs.     

Parental and community acceptance of the benefits and risks associated with meningococcal B vaccines

Objective

A new meningococcal serogroup B (Men B) vaccine has been licensed in the European Union (EU) and Australia. This study aimed to assess community and parental attitudes to introduction of new Men B vaccines and identify facilitators and barriers to vaccine implementation.

Methods

Cross-sectional survey including face-to-face interviews with adolescents, parents and adults from randomly selected households in South Australia in 2012. Survey data were weighted to the age, gender and geographical area profile of the population.

Results

3055 interviews were conducted with individuals aged 15–97 years, including 966 parents. Participation rate was 66.4%. 82.5% (95% CI 79.7–85.4) of parents (797/966) wanted their child to receive the Men B vaccine, with 12.2% (9.7–14.7) (118/966) unsure. Main parental concerns included potential side effects (41.3% (26.7–46.0)) and adequate vaccine testing (11.7% (9.4–14.1)). Potential for an extra injection at an immunisation visit resulted in 15.7% (12.8–18.5) of parents (n = 152/966) less likely to have their child immunised. Potential redness/swelling at the injection site or mild/moderate fever resulted in only 8.5% (6.3–10.7) and 10.8% (8.5–13.2) of parents, respectively, less likely to have their child immunised. Children being up to date with vaccinations and recommendation from family physician were the strongest independent predictors of parents agreeing their children should be immunised with Men B vaccine (OR = 6.58; p = 0.006 and OR = 4.15; p < 0.001, respectively). Only 16.4% (14.9–17.9) of adults (501/3055) stated that they would not want to receive a Men B vaccine, with family physician recommendation the strongest independent predictor of acceptance (OR = 3.81; p < 0.001).

Conclusions

There is strong community support for introduction of Men B vaccines, with parental willingness to have children immunised, impacted more by number of injections than potential for adverse events such as local reactions or fever.     

The inpatient costs and hospital service use associated with invasive meningococcal disease in South Australian children

Background

Invasive meningococcal disease (IMD) remains a serious public health concern due to a sustained high case fatality rate and morbidity in survivors. This study aimed to estimate the hospital service costs associated with IMD and variables associated with the highest costs in Australian children admitted to a tertiary paediatric hospital.

Methods

Clinical details were obtained from medical records and associated inpatient costs were collected and inflated to 2011 Australian dollars using the medical and hospital services component of the Australian Consumer Price Index. Both unadjusted and adjusted analyses were undertaken. Multivariate regression models were used to adjust for potential covariates and determine independent predictors of high costs and increased length of hospital stay.

Results

Of 109 children hospitalised with IMD between May 2000 and April 2011, the majority were caused by serogroup B (70.6%). Presence of sequelae, serogroup B infection, male gender, infants less than one year of age, and previous medical diagnosis were associated with higher inpatient costs and length of stay (LOS) in hospital (p < 0.001) during the acute admissions. Children diagnosed with septicaemia had a longer predicted LOS (p = 0.033) during the acute admissions compared to those diagnosed with meningitis alone or meningitis with septicaemia. Serogroup B cases incurred a significantly higher risk of IMD related readmissions (IRR: 21.1, p = 0.008) for patients with sequelae. Serogroup B infection, male gender, diagnosis of septicaemia, infants less than one year of age, and no previous medical diagnosis were more likely to have higher inpatient costs and LOS during the IMD related readmissions for patients with sequelae (p < 0.05).

Conclusion

Although IMD is uncommon, the disease severity and associated long-term sequelae result in high health care costs, which should be considered in meningococcal B vaccine funding considerations.     

Persistence of the immune response at 5 years of age following infant immunisation with investigational quadrivalent MenACWY conjugate vaccine formulations

Background and aims

Serogroup A, C, W-135 and Y meningococcal (MenACWY) conjugate vaccines are recommended for routine adolescent immunisation in the United States and Canada. We evaluated the persistence of bactericidal antibodies through early childhood, following infant immunisation with varying schedules of MenACWY-CRM₁₉₇ vaccine.

Methods

UK and Canadian infants were immunised with 2–3 doses of MenACWY-CRM₁₉₇ or 2 doses of serogroup C meningococcal (MenC) conjugate vaccine, and either MenACWY-CRM₁₉₇, 1/5 dose of MenACWY polysaccharide vaccine or no booster at 12 months. Control groups recruited at 60 months had received country-specific infant doses of MenC conjugate vaccine. hSBA titres were measured in participants at 40 and 60 months of age.

Results

382 children were enrolled in 12 groups (22–40 per group). By age 60 months, 3–11% of children primed and boosted with MenACWY-CRM₁₉₇ had hSBA titres ≥ 1:8 against serogroup A, 14–45% against serogroup C, 57–85% against serogroup W-135 and 42–71% against serogroup Y. Children primed with MenC and boosted with MenACWY-CRM₁₉₇ had similar results, except for serogroup C (59%). In age-matched controls administered MenC vaccine at 2, 3, and 4 months (UK), 2 and 12 months or 12 months only (Canada), percentages with hSBA titres ≥ 1:8 were 0–3%, 29–53%, 34–36% and 10–29% against serogroups A, C, W-135 and Y respectively.

Conclusions

Serogroup-specific bactericidal antibody wane following infant immunisation with MenACWY-CRM₁₉₇, most markedly against serogroup A. Best persistence against serogroup C is observed with MenC conjugate vaccine priming and MenACWY-CRM₁₉₇ at 12 months, compared to schedules using only MenACWY-CRM₁₉₇, with the potential for providing broader protection compared to monovalent MenC vaccines alone.     

Safety of a quadrivalent meningococcal serogroups A,C, W and Y conjugate vaccine (MenACWY-CRM) administered with routine infant vaccinations: Results of an open-label,randomized, phase 3b controlled study in healthy infants

Background

The highest risk for invasive meningococcal disease (IMD) is in infants aged <1 year. Quadrivalent meningococcal conjugate vaccination has the potential to prevent IMD caused by serogroups A, C, W and Y. This phase 3b, multinational, open-label, randomized, parallel-group, multicenter study evaluated the safety of a 4-dose series of MenACWY-CRM, a quadrivalent meningococcal conjugate vaccine, concomitantly administered with routine vaccinations to healthy infants.

Methods

Two-month-old infants were randomized 3:1 to receive MenACWY-CRM with routine vaccines or routine vaccines alone at ages 2, 4, 6 and 12 months. Adverse events (AEs) that were medically attended and serious adverse events (SAEs) were collected from all subjects from enrollment through 18 months of age. In a subset, detailed safety data (local and systemic solicited reactions and all AEs) were collected for 7 days post vaccination. The primary objective was a non-inferiority comparison of the percentages of subjects with ≥1 severe systemic reaction during Days 1–7 after any vaccination of MenACWY-CRM plus routine vaccinations versus routine vaccinations alone (criterion: upper limit of 95% confidence interval [CI] of group difference <6%).

Results

A total of 7744 subjects were randomized with 1898 in the detailed safety arm. The percentage of subjects with severe systemic reactions was 16% after MenACWY-CRM plus routine vaccines and 13% after routine vaccines alone (group difference 3.0% (95% CI −0.8, 6.4%). Although the non-inferiority criterion was not met, post hoc analysis controlling for significant center and group-by-center differences revealed that MenACWY-CRM plus routine vaccinations was non-inferior to routine vaccinations alone (group difference −0.1% [95% CI −4.9%, 4.7%]). Rates of solicited AEs, medically attended AEs, and SAEs were similar across groups.

Conclusion

In a large multinational safety study, a 4-dose series of MenACWY-CRM concomitantly administered with routine vaccines was clinically acceptable with a similar safety profile to routine vaccines given alone.     

Seasonal influenza vaccine efficacy and its determinants in children and non-elderly adults: A systematic review with meta-analyses of controlled trials

Context

The true level of influenza vaccine efficacy is controversial and many factors may influence its estimation.

Objectives

To estimate the efficacy of vaccination of children and non-elderly adults for the prevention of influenza and to explore the impact of type of vaccine, age, degree of strain matching, influenza type and case ascertainment methods on vaccine efficacy estimates.

Data sources

Medline and EmBase databases until October 2011. References of relevant articles were also reviewed.

Study selection

Controlled trials evaluating seasonal influenza vaccines and presenting incidence of laboratory-confirmed influenza illness were eligible. Studies exploring efficacy after experimental challenge, presenting duplicate data, employing group randomization, or focusing on special populations were excluded.

Data extraction

The vaccine effect on influenza prevention was evaluated by calculating Mantel–Haenszel risk ratios (RR) and using random-effects models. Vaccine efficacies were calculated for each comparison as (1 − RR) × 100.

Results

Thirty studies were included in one or more of a total of 101 analyses, comprising 88.468 study participants. There was evidence of heterogeneity in 49% of the analyses. Summary vaccine efficacy was 65% against any strain, 78% against matched strains and 55% against not-matched strains. Both live-attenuated and inactivated vaccines showed similar levels of protection against not-matched strains (60% and 55%, respectively). Live-attenuated vaccines performed better than inactivated vaccines in children (80% versus 48%), whereas inactivated vaccines performed better than live-attenuated vaccines in adults (59% versus 39%). There was a large difference (20%) in efficacy against influenza A (69%) and influenza B (49%) types for not-matched strains. Summary estimates of vaccine efficacy were highest when ascertainment was based on culture confirmation.

Conclusion

Influenza vaccines are efficacious, but efficacy estimates depend on many variables including type of vaccine and age of vaccinees, degree of matching of the circulating strains to the vaccine, influenza type, and methods of case ascertainment.     

Introducing vaccination against serogroup B meningococcal disease: An economic and mathematical modelling study of potential impact

Background

Meningococcal disease remains an important cause of morbidity and mortality worldwide. The first broadly effective vaccine against group B disease (which causes considerable meningococcal disease in Europe, the Americas and Australasia) was licensed in the EU in January 2013; our objective was to estimate the potential impact of introducing such a vaccine in England.

Methods

We developed two models to estimate the impact of introducing a new ‘MenB’ vaccine. The cohort model assumes the vaccine protects against disease only; the transmission dynamic model also allows the vaccine to protect against carriage (accounting for herd effects). We used these, and economic models, to estimate the case reduction and cost-effectiveness of a number of different vaccine strategies.

Results

We estimate 27% of meningococcal disease cases could be prevented over the lifetime of an English birth cohort by vaccinating infants at 2,3,4 and 12 months of age with a vaccine that prevents disease only; this strategy could be cost-effective at £9 per vaccine dose. Substantial reductions in disease (71%) can be produced after 10 years by routinely vaccinating infants in combination with a large-scale catch-up campaign, using a vaccine which protects against carriage as well as disease; this could be cost-effective at £17 per vaccine dose.

Conclusions

New ‘MenB’ vaccines could substantially reduce disease in England and be cost-effective if competitively priced, particularly if the vaccines can prevent carriage as well as disease. These results are relevant to other countries, with a similar epidemiology to England, considering the introduction of a new ‘MenB’ vaccine.     

Impact on disease incidence of a routine universal and catch-up vaccination strategy against Neisseria meningitidis C in Tuscany,Italy

Background

Invasive infections due to Neisseria meningitidis are still an important public health issue worldwide. In Europe, meningococcal meningitis is differently distributed in the EU countries, but most cases of meningococcal diseases are caused by serogroups B and C. In Italy, each year about 900 cases of bacterial meningitis occur, of whom one third are caused by N. meningitidis. In March 2005, the Regional Health Authority of Tuscany approved a policy of active offer of conjugate meningococcus C (MCC) vaccination with three doses to all newborns at 3, 5 and 13 months of age (subsequently turning to a single dose at 13 months as of 2008) and a catch-up until age 6 years with a single dose.

Objective

The aim of the present study was to evaluate the effectiveness of the vaccination strategy adopted by Tuscany in preventing cases of invasive meningococcal C disease.

Methods

Surveillance data for the calculation of disease incidence, immunization coverage with MCC vaccine and vaccination status of meningitis cases were collected from 2005 to 2011.

Results

Incidence rates of meningococcal meningitis and septicemia decreased in all age groups involved in the immunization campaign, as a result of the progressively increasing vaccination coverage. Since 2006, no cases of invasive meningococcal C infection in vaccinated subjects were observed in Tuscany. A herd immunity effect was measured in unvaccinated age groups.

Conclusion

MCC vaccination implementation in Tuscany was successful in the prevention of meningococcal C disease. Our results should prompt all Italian Regions to consider introducing MCC vaccination in order to protect their 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.     

Determinants of the public intent to receive the seasonal influenza vaccine and protective behaviors: A population-based study in Taiwan

Background and study aims

this study aims to identify the determinants of perceived changes in protective behaviors against seasonal influenza and the intent to receive the seasonal influenza vaccine among Taiwanese in 2011.

Methods

During the early 2011–2012 influenza season, we conducted a nationwide survey with randomly stratified samples and collected 1400 self-reported questionnaires from respondents aged 15 years and above using the computer-aided telephone interviewing software in Taiwan.

Results

One-third of the respondents intended to receive the seasonal influenza vaccine. Knowledge of protective behaviors against influenza was the most common predictor of perceived changes in different protective behaviors and the intent to receive the seasonal influenza vaccine. Older respondents were significantly more inclined to perceive changes in protective behaviors than younger respondents (adjusted odds ratio [AOR] ranging from 1.7 to 2.5). Female respondents were significantly more likely to change their behavior in wearing a face mask (AOR = 1.5; 95% CI, 1.09 to 2.07) and buying antimicrobial products (AOR = 1.45; 95% CI, 1.09 to 1.92) compared with males. Furthermore, recipients of past H1N1 (AOR = 4.45; 95% CI, 3.03 to 6.53) and seasonal influenza vaccines (AOR = 6.1; 95% CI, 3.31 to 11.23) were more likely to obtain the seasonal influenza vaccine. In contrast, individuals aged 30–49 (AOR = 0.53; 95% CI, 0.38 to 0.74) and females (AOR = 0.65; 95% CI, 0.48 to 0.87) were significantly less likely to intend to receive the seasonal influenza vaccine.

Conclusions

The findings suggest that the predictors of perceived changes in protective behaviors and intent to receive the seasonal influenza vaccine differ. We provide perspectives and suggestions for overcoming the perceived barriers and for developing targeted risk-communication campaigns.     

Meningococcal conjugate vaccination among adolescents aged 13–17 years,United States, 2007

Background

An estimated 1000–2000 cases of invasive meningococcal diseases occur annually in the United States. In 2005, a new quadrivalent meningococcal conjugate vaccine (MCV4) was approved and, because of supply constraints, was recommended for routine vaccination of some groups of adolescents. In August 2007, vaccination recommendations were expanded for all adolescents 11–18 years.

Methods

We analyzed data from the 2007 National Immunization Survey-Teen (NIS-Teen), a nationally representative random digit dialed telephone survey. Estimates of MCV4 coverage were assessed from provider-reported vaccination histories. A multivariable logistic regression analysis and predictive marginal model were performed to identify factors independently associated with MCV4 vaccination.

Results

Provider-reported vaccination histories were available for 2947 adolescents aged 13–17 years with a response rate of 55.9%. Overall, MCV4 coverage was 32.4% (95% confidence interval (CI) = 30.2–34.7%) in 2007. Vaccination coverage was similar among adolescents aged 13–14 years compared to those aged 15–17 years (32.1% vs. 32.6%, respectively). Coverage was 30.6% for non-Hispanic whites, 35.9% for non-Hispanic blacks, and 36.1% for Hispanics; however, these variations were not statistically significant. Characteristics independently associated with a higher likelihood of MCV4 vaccination included having ≥2 physician contacts in the past year, having a well child visit at age 11–12 years, and ever having a doctor recommendation for meningitis vaccination of the adolescent.

Conclusions

In 2007, MCV4 coverage among 13–17 years old increased 20.7 percentage points from 2006. Achieving high vaccination coverage among adolescents will be challenging. Targeting adolescents with no health insurance and no recent healthcare provider visits may be important to increase coverage.     

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.     

Hepatitis B virus vaccination by French family physicians

Vaccine coverage against hepatitis B virus (HBV) in France has decreased to one of the lowest levels among countries that recommend it, over the last decade. The probable cause was that the vaccine was suspected to induce demyelinating diseases. We studied the factors limiting the use of HBV vaccine amongst French family physicians (FPs), who play a significant role in the implementation of the vaccination policy.

Method

We conducted a national survey in 2008, using an interactive questionnaire sent by e-mail to 2175 private general practitioners in metropolitan France. This questionnaire provided us with demographic data and information on perception, opinions and practices of FPs regarding HBV vaccination. It also assessed practical barriers to vaccination FPs encountered. The answer structure was analyzed by multiple correspondence analysis (MCA). An agglomerative hierarchical clustering (AHC) identified typical behaviors among FPs. We determined and tested specific links among answers. The representativeness of the final sample (341 FPs) was tested.

Results

HBV vaccination for infants is increasingly recommended; children and teenage vaccine catch-up is less routinely recommended; 25% of FPs are opposed to systematic vaccination; the main barrier to vaccination, according to FPs, remains public opinion on the vaccine's potential adverse effects; barriers among physicians include excessive precaution principle in prescribing the vaccine and misconceptions on hepatitis B and vaccination.     

Increasing adolescent immunization by webinar: a brief provider intervention at federally qualified health centers

Objective

To evaluate a brief intervention to increase provision of adolescent vaccines at health centers that reach the medically underserved.

Method

In April 2010, clinical coordinators from 17 federally qualified health centers (serving 7827 patients ages 12–17) participated in a competition to increase uptake of recommended adolescent vaccines: tetanus, diphtheria, and pertussis booster; meningococcal conjugate; and human papillomavirus. Vaccination coordinators attended a webinar that reviewed provider-based changes recommended by the CDC's Assessment, Feedback, Incentives, and eXchanges (AFIX) program and received weekly follow-up emails. Data on vaccine uptake came from the North Carolina Immunization Registry.

Results

Uptake of targeted adolescent vaccines increased during the one-month intervention period by about 1–2% (all p < .05). These small but reliable increases were greater than those observed for non-targeted vaccines (measles, mumps, and rubella; hepatitis B; and varicella).

Conclusion

This AFIX webinar led to small increases in provision of targeted adolescent vaccines over a one-month period. Similar, sustainable programs at healthcare facilities, including federally qualified health centers that function as safety net providers for medically underserved populations could help reach populations with great need.     

Vaccination with 3-dose paediatric rotavirus vaccine (RotaTeq®): impact on the timeliness of uptake of the primary course of DTPa vaccine

Background

In countries like Australia where high coverage rates of early childhood vaccines has been achieved, ensuring timely vaccination is the next challenge – particularly where multiple doses are required for protection (e.g. DTPa vaccine). Since July 2007, for the first time, the Australian childhood vaccination schedule has included a vaccine (rotavirus vaccine) that must be administered within strict dosing windows.

Aim

To determine whether the introduction of a 3-dose rotavirus vaccine (RotaTeq^®) into the national childhood immunisation program in Victoria, Australia, had an impact on the timeliness of the primary course of DTPa vaccine that is also scheduled at the same ages (2, 4 and 6 months).

Study

We studied de-identified data of >17,000 children residing in four large and culturally diverse localities in the Eastern Region of Melbourne, Victoria who were born prior to or after the introduction of RotaTeq^® into the National Immunisation Program schedule. Timeliness was defined as the proportion of children who received a particular dose of DTPa vaccine within the dosing window for the equivalent dose of RotaTeq^®. We were particularly interested in any change in the timeliness of dose 3 of DTPa vaccine.

Results

Before the introduction of RotaTeq^®, timely uptake of doses 1 and 2 of DTPa vaccine was high (93–97%). However, timeliness of the 3rd dose was markedly lower, dropping to 80% in one locality. In the post-RotaTeq^® cohort, rates of timely uptake for doses 1 and 2 of DTPa vaccine remained high (97–99%). However, for DTPa vaccine dose 3, there was a clear trend toward improved timeliness – increasing by 5 to up to 12 percentage points compared with the pre-RotaTeq^® cohort.

Conclusion

Inclusion in the national immunisation schedule of the 3-dose vaccine RotaTeq^® that has strict dosing windows encourages parents to present in a timely fashion for their child's vaccination, which in turn may drive an improvement in timeliness of other concurrently scheduled vaccines (e.g. DTPa). Introduction of government-funded RotaTeq^® may improve the uptake of the crucial 3rd dose of DTPa vaccine, where traditionally the greatest delays are noted.     

Provider knowledge of trivalent inactivated and high-dose influenza vaccines

Objective

The objective of this study was to assess provider knowledge about trivalent inactivated and high dose influenza vaccines. Hence, a 20-item survey was distributed to providers within the Internal Medicine department at an urban academic medical center.

Results

Two hundred and eighty-one (24.5%) providers responded. The correct response rate was 63.2%. The highest performing subspecialties were infectious diseases (80.5%), endocrinology (69.2%), and pulmonary (68%). Those who received an influenza vaccine during the most recent season scored significantly higher than those who did not (63.6% vs. 43.6%, p = .001). Areas where respondents did poorly included questions pertaining to contraindications to immunizations (27.4%), common adverse events after immunization (29.2%), target antigen (73.5%), number of strains in the trivalent inactivated vaccine (62.9%), and time to immunity (61.4%). High dose vaccine knowledge was poor, with 37% of providers unaware of its existence.

Conclusion

Significant gaps in provider knowledge exist regarding both trivalent inactivated and high dose influenza vaccines.     

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.     

Acceptability of a hypothetical group B strep vaccine among pregnant and recently delivered women

Objective

Group B Streptococcus (GBS) causes significant infant morbidity and mortality. Promising GBS vaccines are currently in clinical trials. Because GBS vaccines would be the first to specifically target pregnant women, we sought to assess acceptability of a hypothetical GBS vaccine.

Study design

We performed an internet survey among currently pregnant or recently delivered women receiving care at one of 9 Ob/Gyn practices in Colorado. Vaccine acceptability was assessed using questions based on constructs from the Health Belief Model. Multivariable analyses assessed the characteristics associated with GBS vaccine acceptability during the current/recent pregnancy.

Results

The response rate was 50% (n = 231). While 78% agreed that a GBS vaccine would be a good way to protect newborns, 90% and 83% agreed, respectively, that they worried generally about the safety and effectiveness of new vaccines. Moreover, 39% believed it is generally dangerous for pregnant women to get vaccines. Seventy nine percent ‘definitely’ or ‘probably’ would have gotten a GBS vaccine in their most recent pregnancy if available. The most influential factors associated with this outcome were a strong belief in the vaccine's benefits (adjusted odds ratio [AOR] 6.37, 95% confidence interval [CI] 2.01–20.16), and low perceived barriers to vaccination (AOR 0.11, 95% CI (0.03–0.37)).

Conclusion

A GBS vaccine may be acceptable to pregnant women but would benefit from strong provider support and education about the risks and consequences of GBS infection and the benefits to vaccination.     

Decreased immune response to pneumococcal conjugate vaccine after 23-valent pneumococcal polysaccharide vaccine in children

Background

Pneumococcal polysaccharide vaccine (PPV) is used in children at high risk of IPD. PPV is generally not considered to induce immunologic memory, whereas pneumococcal conjugate vaccines (PCVs) elicit protective antibody responses in infants and induce immunologic memory. Little is known about the characteristics of immune responses to PCV in children who previously received PCV and PPV in series.

Objective

To characterize immune responses to 13-valent pneumococcal CRM₁₉₇ conjugate vaccine (PCV13; serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, and 23F) in children vaccinated in infancy with 9-valent pneumococcal–meningococcal C-CRM₁₉₇ conjugate combination vaccine (PCV9-MnCC), followed by a toddler dose of PCV9-MnCC or 23-valent pneumococcal polysaccharide vaccine (PPV23).

Methods

Children (n = 89) who received PCV9-MnCC in infancy and PPV23 or PCV9-MnCC at age 12 months in a previous (2002–2003) study were vaccinated at age 7.5 years with PCV13; groups PPV23/PCV13 (n = 50) and PCV9/PCV13 (n = 39). Immunoglobulin (Ig)G antibodies, avidity, and opsonophagocytic activity (OPA) were measured before and at 1 and 4 weeks postvaccination.

Results

One week postvaccination, IgG levels increased significantly for all serotypes in both groups, and >97% of vaccinees achieved IgG ≥0.35 μg/ml 4 weeks after PCV13 vaccination. The PCV9/PCV13 group had higher IgG responses compared with the PPV23/PCV13 group. The upper limits of the 95% confidence intervals of the PPV23/PCV13:PCV9/PCV13 IgG geometric mean concentration ratios were <1.0 for serotypes 1, 4, 5, 9V, 18C, and 23F at 1 week. OPA and avidity results supported these findings.

Conclusions

PPV23 vaccination of toddlers may compromise subsequent responses to pneumococcal conjugate vaccines. The clinical relevance of this finding is unclear.     

Evaluation of meningococcal serogroup C conjugate vaccine programs in Canadian children: interim analysis

Background

To assess antibody titers afforded by meningococcal C- (MenC) tetanus toxoid conjugate vaccine at 12 months of age in three different immunization schedules.

Methods

This prospective study included three similar cohorts of healthy infants from 1-dose, 2-dose and 3-dose MenC infant immunization programs. Infants were enrolled at 12 months of age and given the final scheduled dose of MenC-tetanus toxoid conjugate vaccine with sera collected prior to and 1 month after the vaccination. Serum bactericidal activity (SBA) titers ≥ 1:8 were considered protective.

Results

Before the 12 month dose, participants had significantly different protective titers according to the number of prior doses received: 100% (95% CI 97.6–100%) of infants who had 2 prior doses (at 2 and 4 months) were protected compared to 84.0% (76.7–89.3%) of participants with one dose (at 2 months) and 27.6% (21.0–35.4%) of unvaccinated infants. All subjects were protected after the 12 month MenC dose, but titers were higher with prior priming.

Conclusions

Two MenC doses given in infancy afford optimal protection during the first year of life; however, substantial protection was seen after one dose at 2 months.