Knowledge and attitiudes of pregnant women and their providers towards recommendations for immunization during pregnancy

ObjectivesTetanus, diphtheria and acellular pertussis (Tdap) and influenza vaccination is recommended during each pregnancy but uptake is suboptimal. We evaluated knowledge and acceptance of vaccination recommendations among pregnant women.MethodsProspective, convenience survey of pregnant women presenting for antenatal care at the Pavilion for Women, Texas Children's Hospital, Houston, and their healthcare providers.Results796 of 825 (96.5%) of women and 63 of 87 (72.4%) providers completed surveys. Mean age of pregnant women was 30.2 (18–45) years. Self-identified race/ethnicity was 45% white, 26% Hispanic, 13% black, 12% Asian and 4% other. Most women had college degrees (84%) and private health insurance (83%). Mean gestation was 28.5 weeks with 4.8%, 37.8% and 57.4%, in the 1st, 2nd and 3rd trimesters, respectively. Women used various sources for pregnancy information (personal contacts, providers, print, audiovisual and online media) but 89.1% cited a provider as their most trusted source, predominantly (85.8%) their physician. 668 (84%) knew vaccines are recommended during pregnancy, specifically influenza (77%) and Tdap (61%) vaccines. 659 (83%) were willing to receive vaccines if recommended by their physician. Factors impacting vaccination decisions included safety for baby, safety for mother and sufficient information, scoring 4.7, 4.5 and 4.2, respectively, on a 5-point scale; less important were additional visit time (2.6), cost (1.9) or needle phobia (1). Women surveyed in the 3rd trimester showed greater acceptance than those earlier in gestation (87% vs 78%; P0.003). Maternal education, ethnicity, insurance, multiple gestation or history of serious illness in a prior infant did not affect willingness to receive vaccines.ConclusionsPregnant women are willing to accept vaccination in pregnancy if recommended by their physician and if sufficient discussion of safety and rationale occurs. Strong physician recommendation, as reported for pediatric vaccination, is essential to optimizing uptake of vaccines during pregnancy.     

Strategies for increasing uptake of vaccination in pregnancy in high-income countries: A systematic review

IntroductionVaccination in pregnancy is an effective method to protect against disease for the pregnant woman, foetus and new born infant. In England, it is recommended that pregnant women are vaccinated against pertussis and influenza. Improvement in the uptake of both pertussis and influenza vaccination among pregnant women is needed to prevent morbidity and mortality for both the pregnant women and unborn child.AimTo identify effective strategies in increasing the uptake of vaccination in pregnancy in high-income countries and to make recommendations for England.MethodsA systematic review of peer reviewed literature was conducted using a keyword search strategy applied across six databases (Medline, Embase, PsychInfo, PubMed, CINAHL and Web of Science). Articles were screened against an inclusion and exclusion criteria and papers included within the review were quality assessed.Results and conclusionsTwenty-two articles were included in the review. The majority of the papers included were conducted in the USA and looked at strategies to increase influenza vaccination in pregnancy. There is limited high quality evidence for strategies in high-income countries to increase coverage of pertussis and influenza vaccination in pregnancy. A number of strategies have been found to be effective; reminders about vaccination on antenatal healthcare records, midwives providing vaccination, and education and information provision for healthcare staff and patients. Future interventions to increase vaccination in pregnancy should be evaluated to ensure efficacy and to contribute to the evidence base.     

Combined tetanus-diphtheria and pertussis vaccine during pregnancy: transfer of maternal pertussis antibodies to the newborn

Background and objectivesPertussis is currently an emerging public health concern in some countries with high vaccination coverage. It is expected that maternal pertussis immunization could provide newborn protection. We compared pertussis toxin antibody (anti-PT) levels in women during pregnancy (pre- and post-vaccination) with respect to levels in the newborn at delivery in women vaccinated during pregnancy. We also estimated anti-PT titers at primary infant vaccination.MethodsObservational study of pregnant women vaccinated with Tdap (≥20 weeks gestation) and their newborns between May 2012 and August 2013. Anti-PT levels were determined by ELISA in maternal (pre- and post-vaccination) and newborn blood.ResultsPre-vaccination, post-vaccination maternal and newborn samples were available in 132 subjects. Mean maternal age was 34.2 (SD 4.3) years. Median weeks of gestation at vaccination were 27.2 (Q1–Q3 21.7–30.8). Anti-PT (≥10 IU/ml) levels were found in 37.1% of maternal pre-vaccination samples (geometric mean titer (GMT) 7.9 IU/ml (95% CI 6.8–9.2)), 90.2% of post-vaccination samples (GMT 31.1 IU/ml (95% CI 26.6–36.3)) and 94.7% of newborns (GMT 37.8 IU/ml (95% CI 32.3–44.1)). The Lin concordance index between post-vaccination maternal and newborn samples was 0.8 (95% CI 0.8–0.9). Transplacental transfer ratio was 146.6%. At two months of age, 66% of newborns had estimated anti-PT levels ≥10 IU/ml.ConclusionsThere was a high correlation between anti-PT levels in mothers and newborns, with higher levels in newborns, which should be sufficient to provide protection against pertussis during the first months of life. Vaccination of pregnant women seems to be an immunogenic strategy to protect newborns until primary infant immunization.     

Patient attitudes toward influenza and tetanus,diphtheria and acellular pertussis vaccination in pregnancy

BackgroundRoutine influenza and tetanus, diphtheria and acellular pertussis (Tdap) vaccination of pregnant women to prevent poor maternal, fetal and neonatal outcomes is recommended practice; however, actual rates of influenza vaccine acceptance are typically well below the (Healthy People 2020, 2015) goal of 80%.ObjectiveWe sought to identify barriers to accepting either vaccination.Materials and MethodsFrom December 2014 to April 2015 women were given a questionnaire eliciting their experiences, attitudes and history of influenza and Tdap vaccination in pregnancy during their routine prenatal care appointments at a tertiary care center. Patient demographics were included in the questionnaire. A similar questionnaire was administered to prenatal care providers. Patient influenza and Tdap vaccination acceptance rates were compared and predictors of vaccine acceptance were analyzed with bivariate logistic regression.ResultsOut of the 400 patient questionnaires distributed, 338 (84.5%) were completed and returned; 24 of 45 (53.3%) provider questionnaires were returned. Vaccination acceptance rates were 70.7% for the influenza vaccine and 76.3% for the Tdap vaccine. The logistic regression model indicated that predictors of acceptance for either vaccine in pregnancy are patient attitude and previous vaccination history. Patient attitudes were more favorable towards Tdap than influenza vaccination. The combination of healthcare provider recommendation and educational materials was significantly predictive of both Tdap and influenza vaccine acceptance. The most common reasons given for declining the influenza vaccine were safety concerns; the most common reasons given for declining the Tdap vaccine were that patients did not think it was required again when they received the vaccine before pregnancy.ConclusionsOur study suggests that providers can improve Tdap and influenza vaccination acceptance in pregnancy by recommending the vaccination in combination with provision of educational materials on the vaccines.     

The free vaccination policy of influenza in Beijing,China: The vaccine coverage and its associated factors

BackgroundIn order to improve influenza vaccination coverage, the coverage rate and reasons for non-vaccination need to be determined. In 2007, the Beijing Government published a policy providing free influenza vaccinations to elderly people living in Beijing who are older than 60. This study examines the vaccination coverage after the policy was carried out and factors influencing vaccination among the elderly in Beijing.MethodsA cross-sectional survey was conducted through the use of questionnaires in 2013. A total of 1673 eligible participants were selected by multistage stratified random sampling in Beijing using anonymous questionnaires in-person. They were surveyed to determine vaccination status and social demographic information.ResultsThe influenza vaccination coverage was 38.7% among elderly people in Beijing in 2012. The most common reason for not being vaccinated was people thinking they did not need to have a flu shot. After controlling for age, gender, income, self-reported health status, and the acceptance of health promotion, the rate in rural areas was 2.566 (95% confidence interval [CI], 1.801–3.655, P < 0.010) times greater than that in urban areas. Different mechanisms of health education and health promotion have different influences on vaccination uptake. Those whom received information through television, community boards, or doctors were more likely to get vaccinated compared to those who did not (Odds Ratio [OR] = 1.403, P < 0.010; OR = 1.812, P < 0.010; OR = 2.647, P < 0.010).ConclusionThe influenza vaccine coverage in Beijing is much lower than that of developed countries with similar policies. The rural–urban disparity in coverage rate (64.1% versus 33.5%), may be explained by differing health provision systems and personal attitudes toward free services due to socioeconomic factors. Methods for increasing vaccination levels include increasing the focus on primary care and health education programs, particularly recommendations from doctors, to the distinct target populations, especially with a focus on expanding these efforts in urban areas.     

Association between patient reminders and influenza vaccination status among children

BackgroundPatient reminders are recommended to increase vaccination rates. The objectives of this study were to estimate the percentage of children 6 months–17 years for whom a patient reminder for influenza vaccination was received by a child’s parent or guardian, estimate influenza vaccination coverage by receipt of a patient reminder, and identify factors associated with receipt of a patient reminder.MethodsNational Immunization Survey-Flu (NIS-Flu) data for the 2013–14 influenza season were analyzed. Tests of association between patient reminders and demographic characteristics were conducted using Wald chi-square tests and pairwise comparison t-tests. Multivariable logistic regression was used to determine variables independently associated with receiving a patient reminder.ResultsApproximately 22% of children had a parent or guardian report receiving a patient reminder for influenza vaccination for their child, ranging from 12.9% in Idaho to 41.2% in Mississippi. Children with a patient reminder were more likely to be vaccinated compared with children without a patient reminder (73.7% versus 55.5%). In the multivariable model, reminder receipt was higher for children 6–23 months compared with children 13–17 years, black children compared with white children, and children whose parent completed the survey in English compared with children whose parent completed the survey in a language other than English or Spanish.ConclusionsAlthough patient reminders are associated with a higher likelihood of influenza vaccination, nationally, less than one-fourth of children had a parent report receiving one. Despite being based on parental report, with its limitations, this study suggests that increasing the number of parents who receive patient reminders for their children may improve vaccination coverage among children.     

Influenza vaccination coverage of Vaccine for Children (VFC)-entitled versus privately insured children,United States, 2011–2013

BackgroundThe Vaccines for Children (VFC) program provides vaccines at no cost to children who are Medicaid-eligible, uninsured, American Indian or Alaska Native (AI/AN), or underinsured and vaccinated at Federally Qualified Health Centers or Rural Health Clinics. The objective of this study was to compare influenza vaccination coverage of VFC-entitled to privately insured children in the United States, nationally, by state, and by selected socio-demographic variables.MethodsData from the National Immunization Survey-Flu (NIS-Flu) surveys were analyzed for the 2011–2012 and 2012–2013 influenza seasons for households with children 6 months–17 years. VFC-entitlement and private insurance status were defined based upon questions asked of the parent during the telephone interview. Influenza vaccination coverage estimates of children VFC-entitled versus privately insured were compared by t-tests, both nationally and within state, and within selected socio-demographic variables.ResultsFor both seasons studied, influenza coverage for VFC-entitled children did not significantly differ from coverage for privately insured children (2011–2012: 52.0% ± 1.9% versus 50.7% ± 1.2%; 2012–2013: 56.0% ± 1.6% versus 57.2% ± 1.2%). Among VFC-entitled children, uninsured children had lower coverage (2011–2012: 38.9% ± 4.7%; 2012–2013: 44.8% ± 3.5%) than Medicaid-eligible (2011–2012: 55.2% ± 2.1%; 2012–2013: 58.6% ± 1.9%) and AI/AN children (2011–2012: 54.4% ± 11.3%; 2012–2013: 54.6% ± 7.0%). Significant differences in vaccination coverage among VFC-entitled and privately insured children were observed within some subgroups of race/ethnicity, income, age, region, and living in a metropolitan statistical area principle city.ConclusionsAlthough finding few differences in influenza vaccination coverage among VFC-entitled versus privately insured children was encouraging, nearly half of all children were not vaccinated for influenza and coverage was particularly low among uninsured children. Additional public health interventions are needed to ensure that more children are vaccinated such as a strong recommendation from health care providers, utilization of immunization information systems, provider reminders, standing orders, and community-based interventions such as educational activities and expanded access to vaccination services.     

Influenza vaccine effectiveness against laboratory confirmed influenza in Greece during the 2013–2014 season: A test-negative study

BackgroundIn 2013–2014 Greece experienced a resurgence of severe influenza cases, coincidental with a shift to H1N1pdm09 predominance. We sought to estimate Vaccine Effectiveness (VE) for this season using available surveillance data from hospitals (including both inpatients and outpatients).MethodsSwab samples were sent by hospital physicians to one of three laboratories, covering the entire country, to be tested for influenza using RT-PCR. The test-negative design was employed, with patients testing positive serving as cases and those testing negative serving as controls. VE was estimated using logistic regression, adjusted for age group, sex, region and calendar time, with further adjustment for unknown vaccination status using inverse response propensity weights. Additional age group stratified estimates and subgroup estimates of VE against H1N1pdm09 and H3N2 were calculated.ResultsOut of 1310 patients with known vaccination status, 124 (9.5%) were vaccinated, and 543 patients (41.5%) tested positive for influenza. Adjusted VE was 34.5% (95% CI: 4.1–55.3%) against any influenza, and 56.7% (95% CI: 22.8–75.7%) against H1N1pdm09. VE estimates appeared to be higher for people aged 60 and older, while in those under 60 there was limited evidence of effectiveness. Isolated circulating strains were genetically close to the vaccine strain, with limited evidence of antigenic drift.ConclusionsThese results suggest a moderate protective effect of the 2013–2014 influenza vaccine, mainly against H1N1pdm09 and in people aged 60 and over. Vaccine coverage was very low in Greece, even among groups targeted for vaccination, and substantial efforts should be made to improve it. VE can and should be routinely monitored, and the results taken into account when deciding on influenza vaccine composition for next season.     

Association between provider recommendation and influenza vaccination status among children

BackgroundProvider recommendation is associated with influenza vaccination receipt. The objectives of this study were to estimate the percentage of children 6 months–17 years for whom a provider recommendation for influenza vaccination was received, identify factors associated with receipt of provider recommendation, and evaluate the association between provider recommendation and influenza vaccination status among children.MethodsNational Immunization Survey-Flu (NIS-Flu) parentally reported data for the 2013–14, 2014–15, and 2015–16 seasons were analyzed. Tests of association between provider recommendation and demographic characteristics were conducted using Wald chi-square tests and pairwise comparison t-tests. Multivariable logistic regression was used to determine variables independently associated with receiving provider recommendation and the association between provider recommendation and influenza vaccination status.ResultsApproximately 70% of children had a parent report receiving a provider recommendation for influenza vaccination for their child. The strongest association between receipt of provider recommendation and demographic characteristics was with child’s age, with younger children (6–23 months, 2–4 years, and 5–12 years) being more likely to have a provider recommendation than older children (13–17 years). In addition, children living in a household above poverty with household income >$75,000 were more likely to have a parent report receipt of a provider recommendation than children living below poverty. Children with a provider recommendation were twice as likely to be vaccinated than those without.ConclusionsThis study affirms the importance of provider recommendation for influenza vaccination among children. Ensuring that parents of all children receive a provider recommendation may improve vaccination coverage.     

Pertussis Immunisation in Pregnancy Safety (PIPS) Study: A retrospective cohort study of safety outcomes in pregnant women vaccinated with Tdap vaccine

BackgroundNew Zealand has funded the administration of tetanus, diphtheria and acellular pertussis (Tdap) vaccine during pregnancy to prevent infant pertussis since 2013. The aim of this study was to assess the safety of Tdap vaccine administered to pregnant women as part of a national maternal immunisation programme.MethodsWe conducted a national retrospective observational study using linked administrative New Zealand datasets. The study population consisted of pregnant women eligible to receive funded Tdap vaccination from 28 to 38 weeks gestation in 2013. Primary study outcomes were based on prioritised adverse events for the assessment of vaccine safety in pregnant women, as defined by WHO and Brighton Collaboration taskforces. We examined the effect of Tdap vaccination on prioritised maternal outcomes using Cox proportional hazard models. Adjusted hazard ratios controlled for key confounding variables.ResultsIn the cohort of 68,550 women eligible to receive funded antenatal Tdap vaccination during 2013, 8178 (11.9%) were vaccinated and 60,372 (88.1%) were unvaccinated. The use of Tdap in pregnancy was not associated with an increase in the rate of primary outcomes, including preterm labour; pre-eclampsia; pre-eclampsia with severe features; eclampsia; gestational hypertension; fetal growth restriction; or post-partum haemorrhage. Tdap also did not increase secondary outcomes, including gestational diabetes mellitus; antenatal bleeding; placental abruption; premature rupture of membranes; preterm delivery; fetal distress; chorioamnionitis; or, maternal fever during or after labour. Lactation disorders was the only secondary maternal outcome with a significantly increased hazard ratio. Tdap vaccine had a protective effect on pre-eclampsia with severe features, preterm labour, preterm delivery, and antenatal bleeding.ConclusionWe did not detect any biologically plausible adverse maternal outcomes following Tdap vaccination during pregnancy. This study provides further assurance that Tdap administration during pregnancy is not associated with unexpected safety risks.     

Waning vaccine protection against influenza A (H3N2) illness in children and older adults during a single season

BackgroundRecent studies have suggested that vaccine-induced protection against influenza may decline within one season. We reanalyzed data from a study of influenza vaccine effectiveness to determine if time since vaccination was an independent predictor of influenza A (H3N2).MethodsPatients with acute respiratory illness were actively recruited during the 2007–2008 season. Respiratory swabs were tested for influenza, and vaccination dates were determined by a validated immunization registry. The association between influenza RT-PCR result and vaccination interval (days) was examined using multivariable logistic regression, adjusting for calendar time, age and other confounders.ResultsThere were 629 vaccinated participants, including 177 influenza A (H3N2) cases and 452 test negative controls. The mean (SD) interval from vaccination to illness onset was 101.7 (25.9) days for influenza cases and 93.0 (29.9) days for controls. There was a significant association between vaccination interval and influenza result in the main effects model. The adjusted odds ratio (aOR) for influenza was 1.12 (CI 1.01, 1.26) for every 14 day increase in the vaccination interval. Age modified the association between vaccination interval and influenza (p = 0.005 for interaction). Influenza was associated with increasing vaccination interval in young children and older adults, but not in adolescents or non-elderly adults. Similar results were found when calendar week of vaccine receipt was assessed as the primary exposure variable.ConclusionsIdentification of influenza A (H3N2) was associated with increasing time since vaccination among young children and older adults during a single influenza season.     

Tetanus,diphtheria, and acellular pertussis vaccination during pregnancy and reduced risk of infant acute respiratory infections

BackgroundTo protect infants from pertussis infection, the Advisory Committee on Immunization Practices (ACIP) recommends women receive the tetanus toxoid, reduced diphtheria toxoid, acellular pertussis (Tdap) vaccine between 27 and 36 weeks of pregnancy. Here, we assessed the association between timing of maternal Tdap vaccination during pregnancy and acute respiratory infection (ARI) in infants <2 months of age.MethodsThis retrospective cohort study included 99,434 infants born to active duty military women in the Department of Defense Birth and Infant Health Registry from 2006 through 2013. Multivariable log-binomial regression was used to calculate relative risks (RRs) and 95% confidence intervals (CIs) for the association between maternal Tdap vaccination during pregnancy and infant ARI at <2 months of age.ResultsInfants of mothers who received Tdap vaccination during pregnancy vs those who did not were 9% less likely to be diagnosed with an ARI at <2 months of age (RR, 0.91; 95% CI, 0.84–0.99), and the risk was 17% lower if vaccination was received between 27 and 36 weeks of pregnancy (RR, 0.83; 95% CI, 0.74–0.93). Similar results were observed when comparing mothers who received Tdap vaccination prior to pregnancy in addition to Tdap vaccination between 27 and 36 weeks of pregnancy versus mothers who only received vaccination prior to pregnancy (RR, 0.85; 95% CI, 0.74–0.98).ConclusionsMaternal Tdap vaccination between 27 and 36 weeks of pregnancy was consistently protective against infant ARI in the first 2 months of life vs no vaccination during pregnancy, regardless of Tdap vaccination prior to pregnancy. Our findings strongly support current ACIP guidelines recommending Tdap vaccination in late pregnancy for every pregnancy.     

Improved immunogenicity of high-dose influenza vaccine compared to standard-dose influenza vaccine in adult oncology patients younger than 65 years receiving chemotherapy: A pilot randomized clinical trial

PurposePatients undergoing chemotherapy often fail to develop robust responses to influenza vaccination. Compared to standard-dose influenza vaccine (SD), high-dose influenza vaccine (HD) has shown improved immunogenicity and protection against influenza illness in adults 65 years and older. This study compared the immunogenicity and tolerability of HD to SD in adults younger than 65 years of age receiving chemotherapy.MethodsThis double-blind study randomized patients receiving chemotherapy to vaccination with either SD or HD influenza vaccine. Hemagglutination inhibition assays (HAI) were performed prior to and 4 weeks after vaccination. HAI were summarized as geometric mean titers (GMT), seroconversion rates, and seroprotection rates.ResultsA total of 105 subjects were enrolled in the trial (51 received SD and 54 received HD). Subjects were well matched for demographic and medical conditions. Both vaccines were well tolerated with no SAEs. Of the 100 subjects with evaluable data, seroconversion rates for all 3 influenza antigens & post-vaccination GMTs for H3N2 & B strains were significantly improved with HD compared to SD. Seroprotection was excellent and equivalent in both groups.ConclusionsTrivalent high-dose influenza vaccine can be safely administered to patients receiving chemotherapy with improved immunogenicity and seroconversion compared to standard-dose vaccine. Post-vaccination seroprotection rates were similar in both groups. A larger study is needed to show clinical benefits with HD in this population.This study was registered at ClinicalTrials.gov as NCT01666782.     

The effectiveness of influenza vaccination in preventing hospitalisation in children in Western Australia

BackgroundThere is increasing evidence demonstrating influenza vaccine effectiveness (VE) in the prevention of influenza in children, including the very young. Data demonstrating the effectiveness against severe disease, including hospitalisation, are limited. We aimed to determine the VE of the southern hemisphere trivalent inactivated influenza vaccine (TIV) in preventing laboratory-confirmed influenza-associated hospitalisation in children.Patients and MethodsLaboratory records were used to identify children with confirmed influenza hospitalised (i.e., cases) during a 5 year period (2008, 2010–2013) at the only tertiary paediatric facility in Western Australia. Cases and time, age and ward matched controls were retrospectively reviewed to determine risk factors, vaccination status and outcome. Adjusted odds ratios and VE estimates were derived using conditional logistic regression models.ResultsThree hundred and eighty five cases were identified (Influenza A, 64.9%; Influenza B, 35.1%). Influenza-like illness and pneumonia were the most frequent presentation (74.5% and 23.9%, respectively). The median length of stay was 2 days (Interquartile range 1–4 days). Twenty children (5.2%) required admission to the intensive care unit. Vaccine uptake in cases and controls was low (4.9% and 8.5%, respectively). Three hundred and six case-control pairs were included in the VE analysis, of which 19 pairs were informative with discrepant vaccination status. VE (fully vaccinated vs. unvaccinated) was estimated to be 62.3% (95% CI: −6.6%, 86.7%).ConclusionIn this study, the point estimate for the effectiveness of TIV in preventing influenza-associated hospitalisation in children was similar to that reported for emergency or outpatient attended, laboratory-confirmed influenza, yet confidence intervals were wide. Vaccine uptake remains low. Studies, enroling larger numbers of children, ideally with higher vaccine uptake, are needed to provide additional evidence on TIV protection against influenza hospitalisation in children.     

Hepatitis A vaccination coverage among adolescents (13–17 years) in the United States, 2008–2016

BackgroundThe hepatitis A (HepA) vaccine was recommended by the Advisory Committee on Immunization Practices (ACIP) incrementally from 1996 to 1999. In 2006, HepA vaccine was recommended (1) universally for children aged 12–23 months, (2) for persons who are at increased risk for infection, or (3) for any person wishing to obtain immunity. Catch-up vaccination can be considered.ObjectiveTo assess HepA vaccine coverage among adolescents and factors independently associated with vaccination administration in the US.MethodsThe 2008–2016 National Immunization Survey–Teen was utilized to determine 1 and ≥2 dose HepA vaccination coverage among adolescents aged 13–17 years. Factors associated with HepA vaccine series initiation (1 dose) were determined by bivariate and multivariable analyses. Data were stratified by state groups based on ACIP recommendation: universal child vaccination recommended since 1999 (group 1); child vaccination considered since 1999 (group 2); universal child vaccination recommendation since 2006 (group 3).ResultsIn 2016, national vaccination coverage for 1 and ≥2 doses of HepA vaccine among adolescents was 73.9% and 64.4%, respectively. Nationally, a 40 percentage point increase in vaccination coverage occurred among adolescents born in 1995 compared to adolescents born in 2003. Nationally, the independent factors associated with increased vaccine initiation was race/ethnicity (Hispanic, American Indian/Alaskan Native, Asian), military payment source and provider recommendation for HepA vaccination (2008–2013). Living in a suburban or rural region, living in poverty (level <1.33–5.03), and absence of state daycare or school HepA requirement were common factors associated with decreased likelihood of vaccine initiation.ConclusionsEfforts to increase HepA vaccine coverage in adolescents in all regions of the country would strengthen population protection from hepatitis A virus (HAV).     

Do parents prefer inactivated or live attenuated influenza vaccine for their children?

ObjectivesTo determine the proportion of children whose parents prefer them to receive live, attenuated influenza vaccine (LAIV) or inactivated influenza vaccine (IIV), examine reasons for preferences, and determine what percentage of vaccinated children receive other than the preferred type of vaccine and why.MethodsParental-reported data for the 2014–15 and 2015–16 influenza seasons from the National Immunization Survey-Flu (NIS-Flu), a random-digit-dialed, dual frame (landline and cellular telephone) survey of households with children, were analyzed. We calculated the proportions of vaccinated children aged 2–17 years whose parents preferred LAIV, IIV, or had no preference, and the proportions that were vaccinated with other than the preferred type of vaccine.ResultsFor the 2014–15 and 2015–16 seasons, 55.2% and 53.7%, respectively, of vaccinated children had parents who reported no preference for either IIV or LAIV. The percentage who preferred LAIV was 22.7% and 21.7%, and IIV was 22.1% and 24.7%. The most common reason given by parents for preferring LAIV was the child’s fear of needles (70.9%) and for preferring IIV was belief that the shot is more effective (29.0%). Approximately one-third of vaccinated children whose parents preferred LAIV received IIV only.ConclusionsThe main finding of this study was that most parents do not have a vaccine type preference for their children. The lack of overwhelming preference is advantageous for the maintenance of vaccination coverage levels during times when one vaccine type is not available or not recommended such as in the 2016–17 and 2017–18 seasons when there was a temporary recommendation not to administer LAIV.     

Immunogenicity and safety of double versus standard dose of the seasonal influenza vaccine in solid-organ transplant recipients: A randomized controlled trial

BackgroundThe use of vaccines with higher doses of antigen is an attractive strategy to improve the immunogenicity of influenza vaccination in transplant recipients. However, the effect of vaccination with a double-dose (DD) containing 30 µg of antigen in this population remains unknown.MethodsWe performed a randomized controlled trial to compare the immunogenicity and safety of DD (30 µg) vs. standard dose (SD, 15 µg) of a trivalent inactivated influenza vaccine in kidney and liver transplant recipients. Immunogenicity was assessed by hemagglutination-inhibition assay. Vaccine response was defined as seroconversion to at least one viral strain 2 weeks after vaccination and seroprotection as a titer ≥40.ResultsSixty-three kidney and 16 liver transplant recipients were enrolled. Forty patients received the DD and 39 the SD vaccine. Overall, 40% of patients in the DD compared to 26% in the SD group (P = 0.174) responded to vaccine. In the DD arm, more patients were seroprotected to all viral strains after vaccination (88% vs 69%, P = 0.048). Post vaccination geometric mean titers of antibodies were 131.9 vs. 89.7 (P = 0.187) for H1N1, 185.4 vs. 138.7 (P = 0.182) for H3N2, and 96.6 vs. 68.8 (P = 0.081) for influenza B with the DD vs. SD. In both groups, most of the adverse events were mild and no vaccine-related severe adverse events were observed.ConclusionDouble-dose influenza vaccine is safe and may increase antibody response in transplant recipients. In this population, DD vaccination could be an alternative when high-dose vaccine is not available. NCT02746783.     

Why do we not want to recommend influenza vaccination to young children? A qualitative study of Australian parents and primary care providers

IntroductionInfluenza vaccination has been shown to be safe and effective against influenza and in the prevention of complicating secondary respiratory illnesses. However, its uptake in young children remains low. This study explored the views, attitudes and practices of parents and primary care providers (PCPs) on their knowledge and acceptance of influenza vaccination in children under 5.MethodsUsing a cross-sectional qualitative research design, we conducted 30 in-depth interviews with PCPs (i.e., general practitioners, practice nurses, maternal and child health nurses, and pharmacists) and five focus groups with parents (n = 50) between June 2014 and July 2015 in Melbourne, Australia. Data were thematically analysed.ResultsParents thought the vaccine could cause influenza, and influenza vaccination was not necessary for their children as they needed to build their own ‘immunity’. Parents said that they would consider vaccinating their children if recommended by their GP and if the influenza vaccine was part of the immunisation schedule. PCPs also expressed concerns regarding the efficacy of the vaccine as well as out-of-pocket costs incurred by families, and uncertainty regarding the mortality and morbidity of influenza in otherwise healthy children. However, they said they would recommend the vaccine to high-risk groups (e.g. children with chronic disease(s), and asthma).ConclusionDespite the established safety of influenza vaccines, barriers to uptake include concerns regarding the iatrogenic effects of vaccination, its administration schedule, and knowledge of influenza severity. Updated information on influenza and the efficacy of the vaccine, and incorporating influenza vaccination into the immunisation schedule may overcome some of these barriers to increase influenza vaccination in this vulnerable cohort.     

MMR vaccination status of children exempted from school-entry immunization mandates

BackgroundChild immunizations are one of the most successful public health interventions of the past century. Still, parental vaccine hesitancy is widespread and increasing. One manifestation of this are rising rates of nonmedical or “personal beliefs” exemptions (PBEs) from school-entry immunization mandates. Exemptions have been shown to be associated with increased risk of disease outbreak, but the strength of this association depends critically on the true vaccination status of exempted children, which has not been assessed.ObjectiveTo estimate the true measles-mumps-rubella (MMR) vaccination status of children with PBEs.MethodsWe use administrative data collected by the California Department of Public Health in 2009 and imputation to estimate the MMR vaccination status of children with PBEs under varying scenarios.ResultsResults from 2009 surveillance data indicate MMR1/MMR2 coverage of 18–47% among children with PBEs at typical schools and 11–34% among children with PBEs at schools with high PBE rates. Imputation scenarios point to much higher coverage (64–92% for MMR1 and 25–58% for MMR2 at typical schools; 49–90% for MMR1 and 16–63% for MMR2 at high PBE schools) but still below levels needed to maintain herd immunity against measles.ConclusionsThese coverage estimates suggest that prior analyses of the relative risk of measles associated with vaccine refusal underestimate that risk by an order of magnitude of 2–10 times.     

Decennial administration in young adults of a reduced-antigen content diphtheria,tetanus, acellular pertussis vaccine containing two different concentrations of aluminium

BackgroundRegular booster vaccination might be necessary throughout life to protect against pertussis infection. Nevertheless the duration of protection after booster vaccination remains unclear. In this study, antibody persistence up to 10 years after previous vaccination of adolescents (N = 478) with combined reduced-antigen-content diphtheria-tetanus-acellular pertussis vaccine (dTpa, Boostrix™, GlaxoSmithKline Belgium) containing 0.5 mg, 0.3 mg or 0.133 mg of aluminium was assessed. The immunogenicity, reactogenicity and safety of a decennial booster dTpa dose were also investigated.MethodsYoung adults vaccinated as adolescents in the initial booster study were invited to participate in an assessment of antibody persistence at years 8.5 and 10, and to receive a dTpa booster dose at year 10 with immunogenicity assessment one month later. Those who originally received the 0.5 mg or 0.3 mg formulations received the same vaccine at year 10. Those in the 0.133 mg group received the 0.5 mg formulation. Reactogenicity and safety endpoints were captured until 30 days after booster vaccination.ResultsPrior to the decennial booster at year 8.5 and year 10, all participants had seroprotective antibodies for diphtheria (ELISA or neutralisation assay) and tetanus. At least 77.8% were seropositive for anti-pertussis toxin (PT) antibodies at year 8.5 and 82.8% at year 10. All participants were seropositive for antibodies for filamentous haemagglutinin and pertactin at both time points. The decennial booster dose induced robust increases in antibody GMCs to all antigens. The post-booster anti-PT geometric mean concentration was 82.5 EL.U/ml (95%CI 67.0–101.6) and 124.0 (103.5–148.5) in the 0.3 mg and 0.5 mg groups, respectively. The reactogenicity and safety profile of the decennial booster dose was consistent with the known safety profile of dTpa. No serious adverse events were reported.ConclusionsDecennial booster vaccination with either of the two licensed formulations of dTpa was highly immunogenic and well tolerated in young adults. Either formulation could be confidently used as a decennial booster.This study is registered at www.clinicaltrials.gov NCT01147900