Clinician satisfaction with vaccination visits and the role of multiple injections, results from the COVISE Study (Combination Vaccines Impact on Satisfaction and Epidemiology)

Safety and immunogenicity of a combined DTacP-sIPV-Hib vaccine in animal models

The DTacP-sIPV-Hib combination vaccine can replace the single-component acellular pertussis, diphtheria, tetanus, polio, and Haemophilus influenzae type B vaccines. In this study, we evaluated the safety and immunogenicity of a newly developed DTacP-sIPV-Hib combination vaccine in animal models. We used 40 mice and 46 cynomolgus monkeys to evaluate acute and long-term toxicity. Thirty-six guinea pigs were used for sensitization assessment. For immunogenicity assessment, 50 NIH mice and 50 rats were equally randomized to receive 3 doses of 3 different batches of the tested vaccine at an interval of 21 d, or physiological saline solution (0.5 mL). Orbital blood was collected at an interval of 21 d post inoculation to detect related antibody titers or neutralizing antibody titers against poliovirus. Gross autopsy and histopathological examination revealed no abnormal toxicity or irritation in mice and cynomolgus monkeys. Sensitization assessment in guinea pigs indicated the lack of evident allergic symptoms in the high- and low-dose vaccine groups within 30 min after repeated stimulation. The DTacP-sIPV-Hib combination vaccine induced significant immune responses in mice, rats, and cynomolgus monkeys, with 100% seroconversion rates after 3 doses. The DTacP-sIPV-Hib combination vaccine is safe and immunogenic in animal models. Three doses of the vaccine elicited satisfactory antibody responses in mice, rats, and cynomolgus monkeys.

Timing of Monovalent Vaccine Administration in Infants Receiving DTaP-based Combination Vaccines in the United States

BACKGROUND

The recommended US infant immunization schedule includes doses of diphtheria, tetanus, acellular pertussis (DTaP), inactivated poliovirus (IPV), Haemophilus influenzae type b (Hib) and hepatitis B virus (HepB) during the first 6 months of life. Little information is available about the timing of associated, complementary monovalent vaccine administration in infants receiving DTaP-based pentavalent combination vaccines.

METHODS

This was a retrospective cohort study of infants born between July 1, 2010, and June 30, 2018, in the US MarketScan commercial claims and encounters database. Descriptive statistics were used to assess vaccine administration patterns. Multivariate logistic regression was performed to explore factors associated with coadministration of DTaP-IPV/Hib and HepB.

RESULTS

Among infants who received DTaP-HepB-IPV (n = 129,885), 93.7% had claims for at least 2 Hib doses; most (91.5%-98.3%) of these doses were administered on the same day as DTaP-HepB-IPV doses. Among infants who received DTaP-IPV/Hib (n=214,172), 95.3% had claims for ≥2 doses of HepB. Although coverage was high, 59.2% received the second HepB dose on the same day as the first DTaP-IPV/Hib dose, and 44.6% received the third dose of HepB on the same day as the third DTaP-IPV/Hib dose. Differences in coadministration of the second and third HepB doses with DTaP-IPV/Hib were associated with the region of residence, provider type, health plan type and coadministration of pneumococcal conjugate vaccine and rotavirus vaccine.

CONCLUSIONS

Almost all infants received the appropriate, complementary monovalent vaccine series. However, this study found variability in the timing of HepB doses in relation to DTaP-IPV/Hib doses with many infants not completing the HepB series until 9 months of age.

Frequency and cost of live vaccines administered too soon after prior live vaccine in children aged 12 months through 6 years, 2014-2017

OBJECTIVE

To identify number of children who received live vaccines outside recommended intervals between doses and calculate corrective revaccination costs.

METHODS

We analyzed >1.6 million vaccination records for children aged 12 months through 6 years from six immunization information system (IIS) Sentinel Sites from 2014-15 when live attenuated influenza vaccine (LAIV, FluMist® Quadrivalent) was recommended for use, and from 2016-17, when not recommended for use. Depending on the vaccine, insufficient intervals between live vaccine doses are less than 24 or 28 days from a preceding live vaccine dose. Private and public purchase costs of vaccines were used to determine revaccination costs of live vaccine doses administered during the live vaccine conflict interval. Measles, mumps, rubella (MMR), varicella, combined MMRV, and LAIV were live vaccines evaluated in this study.

RESULTS

Among 946,659 children who received at least one live vaccine dose from 2014-15, 4,873 (0.5%) received at least one dose too soon after a prior live vaccine (revaccination cost, $786,413) with a median conflict interval of 16 days. Among 704,591 children who received at least one live vaccine dose from 2016-17, 1,001 (0.1%) received at least one dose too soon after a prior live vaccine (revaccination cost, $181,565) with a median conflict interval of 14 days. The live vaccine most frequently administered outside of the recommended intervals was LAIV from 2014-15, and varicella from 2016-17.

CONCLUSIONS

Live vaccine interval errors were rare (0.5%), indicating an adherence to recommendations. If all invalid doses were corrected by revaccination over the two time periods, the cost within the IIS Sentinel Sites would be nearly one million dollars. Provider awareness about live vaccine conflicts, especially with LAIV, could prevent errors, and utilization of clinical decision support functionality within IISs and Electronic Health Record Systems can facilitate better vaccination practices.

Knowledge and practices regarding infant vaccination: results of a survey of French physicians

A prospective, observational, survey of pediatricians and general practitioners (GPs) was conducted to assess pediatric vaccination knowledge and practices. The survey was distributed by email to 1069 pediatricians and 1700 GPs and completed by 151 pediatricians (14.1%) and 201 GPs (11.8%). Knowledge of the vaccination calendar was very good (99% overall). Of the respondents, 98% were confident in vaccine efficacy. Eight-one percent of pediatricians and 62% of GPs agreed that recommended vaccinations should become obligatory; all prescribed hexavalent vaccines often or always. More pediatricians (88%) than GPs (75%) used anti-pyretics; the use of anesthetic cream/patches was similar in each group (79% and 75%, respectively). The ambience at vaccination was considered to be important by both groups, and was disturbed in 37% of cases. Seventy percent of pediatricians and 57% of GPs agreed that vaccine reconstitution (e.g., Hib pellet) is a complicating factor: overall, 28% reported occasionally omitting to reconstitute a pentavalent or hexavalent vaccine in error, and 60% reported having not fully reconstituted the vaccine. Almost all (93%) considered non-reconstitution as an important error.Conclusion: Overall, adherence to good vaccination practices was good, although errors in reconstitution were reported by physicians. These problems would be minimized by wider use of fully liquid vaccines. What is Known: • Pediatric vaccination schedules are crowded. • Good vaccination practices and the use of multivalent vaccines are essential to maintain good compliance to pediatric vaccination recommendations. What is New: • Overall good compliance to good vaccination practices by both pediatricians and GPs in France. • Omission of pentavalent or hexavalent vaccine reconstitution of Hib pellet and incomplete reconstitution reported by pediatricians/GPs. Awareness of pediatricians/GPs that omission and incomplete reconstitution are important errors.

Increased Immune Response Variability during Simultaneous Viral Coinfection Leads to Unpredictability in CD8 T Cell Immunity and Pathogenesis

T cell memory is usually studied in the context of infection with a single pathogen in naive mice, but how memory develops during a coinfection with two pathogens, as frequently occurs in nature or after vaccination, is far less studied. Here, we questioned how the competition between immune responses to two viruses in the same naive host would influence the development of CD8 T cell memory and subsequent disease outcome upon challenge. Using two different models of coinfection, including the well-studied lymphocytic choriomeningitis (LCMV) and Pichinde (PICV) viruses, several differences were observed within the CD8 T cell responses to either virus. Compared to single-virus infection, coinfection resulted in substantial variation among mice in the size of epitope-specific T cell responses to each virus. Some mice had an overall reduced number of virus-specific cells to either one of the viruses, and other mice developed an immunodominant response to a normally subdominant, cross-reactive epitope (nucleoprotein residues 205 to 212, or NP205). These changes led to decreased protective immunity and enhanced pathology in some mice upon challenge with either of the original coinfecting viruses. In mice with PICV-dominant responses, during a high-dose challenge with LCMV clone 13, increased immunopathology was associated with a reduced number of LCMV-specific effector memory CD8 T cells. In mice with dominant cross-reactive memory responses, during challenge with PICV increased immunopathology was directly associated with these cross-reactive NP205-specific CD8 memory cells. In conclusion, the inherent competition between two simultaneous immune responses results in significant alterations in T cell immunity and subsequent disease outcome upon reexposure.

IMPORTANCE

Combination vaccines and simultaneous administration of vaccines are necessary to accommodate required immunizations and maintain vaccination rates. Antibody responses generally correlate with protection and vaccine efficacy. However, live attenuated vaccines also induce strong CD8 T cell responses, and the impact of these cells on subsequent immunity, whether beneficial or detrimental, has seldom been studied, in part due to the lack of known T cell epitopes to vaccine viruses. We questioned if the inherent increased competition and stochasticity between two immune responses during a simultaneous coinfection would significantly alter CD8 T cell memory in a mouse model where CD8 T cell epitopes are clearly defined. We show that some of the coinfected mice have sufficiently altered memory T cell responses that they have decreased protection and enhanced immunopathology when reexposed to one of the two viruses. These data suggest that a better understanding of human T cell responses to vaccines is needed to optimize immunization strategies.

Experiences with provider and parental attitudes and practices regarding the administration of multiple injections during infant vaccination visits: lessons for vaccine introduction

INTRODUCTION

An increasing proportion of childhood immunization visits include administration of multiple injections. Future introduction of vaccines to protect against multiple diseases will further increase the number of injections at routine immunization childhood visits, particularly in developing countries that are still scaling up introductions. Parental and healthcare provider attitudes toward multiple injections may affect acceptance of recommended vaccines, and understanding these attitudes may help to inform critical decisions about vaccine introduction.

METHODS

We conducted a systematic review of the literature to examine factors underlying reported parental and healthcare provider concerns and practices related to administration of multiple injections during childhood vaccination visits.

RESULTS

Forty-four articles were identified; 42 (95%) were from high income countries, including 27 (61%) from the USA. Providers and parents report concerns about multiple injections, which tend to increase with increasing numbers of injections. Common parental and provider concerns included apprehension about the pain experienced by the child, worry about potential side effects, and uncertainty about vaccine effectiveness. Multiple studies reported that a positive provider recommendation to the parent and a high level of concern about the severity of the target disease were significantly associated with parental acceptance of all injections. Providers often significantly overestimated parental concerns about multiple injections.

DISCUSSION

Providers may play a critical role in the decision for a child to receive all recommended injections. Their overestimation of parental concerns may lead them to postpone recommended vaccinations, which may result in extra visits and delayed vaccination. More research is needed on interventions to overcome provider and parental concern about multiple injections, particularly in developing countries.

A population-based, postlicensure evaluation of the safety of a combination diphtheria, tetanus, acellular pertussis, hepatitis B, and inactivated poliovirus vaccine in a large managed care organization

BACKGROUND

Prelicensure studies of diphtheria, tetanus, acellular pertussis, hepatitis B, inactivated polio virus vaccine suggested that there were higher rates of fever after its administration than when its component antigens were given separately.

METHODS

We conducted an open, controlled, cohort study to evaluate selected potential adverse events after receipt of diphtheria, tetanus, acellular pertussis, hepatitis B, inactivated poliovirus vaccine in the Southern California Kaiser Permanente Health Care Plan. From April 2003 through June 2005, we identified 61,004 infants who received >or=1 dose of vaccine (120000 total doses). This group was compared with a previous cohort of 58,251 age-, gender-, and medical center-matched infants (116,637 doses) who received diphtheria, tetanus, acellular pertussis vaccine and separate doses of hepatitis B and inactivated poliovirus vaccines from January 2002 through March 2003. We compared the incidence of seizures, medically attended events that were associated with fever, and other selected adverse outcomes.

RESULTS

We identified 16 infants (8 with fever) who had a seizure in the diphtheria, tetanus, acellular pertussis, hepatitis B, inactivated poliovirus cohort and 15 infants (6 with fever) among control subjects in the 8-day period after receipt of any dose of vaccine. The incidence of all seizures or seizures associated with fever was not significantly different between cohorts. The incidence of medically attended events that were associated with fever in the 4-day period after any dose of vaccine was also similar in both cohorts. As well, no significant differences between the diphtheria, tetanus, acellular pertussis, hepatitis B, inactivated poliovirus and control cohorts, were noted in the incidence of allergic reactions within 48 hours of any dose of vaccine, outpatient visits within 21 days, hospitalizations within 21 days, or death within 1 year.

CONCLUSIONS

We did not observe a statistically significant increase in any of several clinically important safety events after diphtheria, tetanus, acellular pertussis, hepatitis B, inactivated poliovirus vaccination compared with a historical cohort who received separate component vaccines.

Societal impact of combination vaccines: experiences of physicians, nurses, and parents

Crowded immunization schedules can result in missed or delayed dosing. Combination vaccines help immunize children on time, limit the required number of injections, and allow new vaccines to be added to the schedule. In the United States, a pentavalent vaccine combining diphtheria, tetanus toxoids, and acellular pertussis (DTaP), recombinant hepatitis B (HepB), and inactivated poliovirus vaccine (IPV) is available. Here, we describe the findings of informal surveys among providers, nurse managers, business managers, and parents on their attitudes toward and experiences with the DTaP-HepB-IPV vaccine. Combination vaccine use is expected to increase as more become available and awareness of their benefits grows.

Delays in immunization have potentially serious health consequences

When children are not administered vaccinations according to the recommended schedule, they not only fail to receive timely protection from preventable diseases at a time when they are most vulnerable, but also increase their risk of never fully completing the vaccination course. Both outcomes compromise a successful childhood immunization program. Although current data suggest that vaccination rates are near 95% for school-aged children in the US, the rate of timely vaccination is much lower. A number of large studies have found that the majority of children are not currently vaccinated on schedule. Moreover, immunization levels for 2- to 3-year-old children have reached a plateau. It is essential to recognize that low overall rates of the targeted diseases mask the persistent threat they pose if adherence to vaccination schedules declines. A delay in one vaccine will produce a domino effect if catch-up adjustments in scheduled visits are not implemented aggressively. Published reports have demonstrated that failure to adhere to scheduled booster immunizations, not just the initial inoculation, results in resurgence of disease. Children fall off the vaccination schedule for a variety of reasons. Although many studies suggest that inadequate availability to healthcare is not a major determinant of delayed immunization, it still factors into parental decisions. Parents should be reminded of available healthcare options. From the clinician's end, computerization of healthcare records should allow for the generation of reminders. It is vital for clinicians to be aware that there are few contraindications to vaccination. They should also be prepared to address parental concerns regarding the safety of vaccines and should not hesitate to use topical analgesics or distraction techniques to facilitate inoculation. With the anticipation of several novel vaccines being added to the childhood and adolescent immunization schedule in the future, pediatricians face new challenges to not only provide every vaccination, but to do so in a timely manner. A lack of willingness on the part of the parent, or, occasionally, on the part of the clinician, to have multiple vaccines administered to the child during a single visit has been shown to be a significant cause of delayed vaccination. Since combination vaccines reduce the number of shots that need to be administered, the use of combination vaccines may provide the best opportunity to simplify the immunization schedule, increasing adherence in the process. Improved adherence to established schedules may present a major opportunity to further protect children from disease.

Use of combination vaccines is associated with improved coverage rates

BACKGROUND

The number of shots represented by the routine childhood immunization schedule poses a logistical challenge for providers and a potential deterrent for parents. By reducing the number of injections, use of combination vaccines could lead to fewer deferred doses and improved coverage rates.

OBJECTIVE

To determine the effect of combination vaccines on coverage rates.

METHODS

This was a retrospective study of administrative claims data from the Georgia Department of Community Health Medicaid program conducted from January through September of 2003. Coverage rates were compared between children who received at least 1 dose of HepB/Hib (COMVAX) or DTaP/HepB/IPV (PEDIARIX) (the combination cohort) and children who received no doses of either combination (the reference cohort). Infants with fewer than 4 vaccination visits were excluded from the analysis. Multivariate logistic regression was performed on the whole study population to assess the effect of combination vaccines while controlling for potential confounders. Hepatitis B and pneumococcal conjugate vaccine coverage rates were not included as outcomes.

RESULTS

The study population consisted of 18,821 infants, 16,007 in the combination cohort and 2814 in the reference cohort. Unadjusted coverage rates for DTaP, IPV and the 4 DTaP:3 IPV:1 MMR, 4 DTaP: 3 IPV: 1 MMR: 3 Hib: 1 varicella, and 3 DTaP:3 IPV: 3 Hib series were higher in the combination cohort. Receipt of at least 1 dose of a combination vaccine was independently associated with increased coverage for each of these vaccines and vaccine series when controlling for gender, birth quarter, race, rural versus urban residence and historical provider immunization quality.

CONCLUSIONS

Use of combination vaccines in this Medicaid population was associated with improved coverage rates. Additional studies are warranted, including those examining private sector populations and outcomes such as timeliness and cost.

Impact of the introduction of pneumococcal conjugate vaccine on immunization coverage among infants

Background

The introduction of pneumococcal conjugate vaccine (PCV) to the U.S. recommended childhood immunization schedule in the year 2000 added three injections to the number of vaccinations a child is expected to receive during the first year of life. Surveys have suggested that the addition of PCV has led some immunization providers to move other routine childhood vaccinations to later ages, which could increase the possibility of missing these vaccines. The purpose of this study was to evaluate whether introduction of PCV affected immunization coverage for recommended childhood vaccinations among 13-month olds in four large provider groups.

Methods

In this retrospective cohort study, we analyzed computerized data on vaccinations for 33,319 children in four large provider groups before and after the introduction of PCV. The primary outcome was whether the child was up to date for all non-PCV recommended vaccinations at 13 months of age. Logistic regression was used to evaluate the association between PCV introduction and the primary outcome. The secondary outcome was the number of days spent underimmunized by 13 months. The association between PCV introduction and the secondary outcome was evaluated using a two-part modelling approach using logistic and negative binomial regression.

Results

Overall, 93% of children were up-to-date at 13 months, and 70% received all non-PCV vaccinations without any delay. Among the entire study population, immunization coverage was maintained or slightly increased from the pre-PCV to post-PCV periods. After multivariate adjustment, children born after PCV entered routine use were less likely to be up-to-date at 13 months in one provider group (Group C: OR = 0.5; 95% CI: 0.3 – 0.8) and were less likely to have received all vaccine doses without any delay in two Groups (Group B: OR = 0.4, 95% CI: 0.3 – 0.6; Group C: OR = 0.5, 95% CI: 0.4 – 0.7). This represented 3% fewer children in Group C who were up-to-date and 14% (Group C) to 16% (Group B) fewer children who spent no time underimmunized at 13 months after PCV entered routine use compared to the pre-PCV baseline. Some disruptions in immunization delivery were also observed concurrent with temporary recommendations to suspend the birth dose of hepatitis B vaccine, preceding the introduction of PCV.

Conclusion

These findings suggest that the introduction of PCV did not harm overall immunization coverage rates in populations with good access to primary care. However, we did observe some disruptions in the timely delivery of other vaccines coincident with the introduction of PCV and the suspension of the birth dose of hepatitis B vaccine. This study highlights the need for continued vigilance in coming years as the U.S. introduces new childhood vaccines and policies that may change the timing of existing vaccines.

Physicians' satisfaction with a collaborative disease management program for late-life depression in primary care

OBJECTIVE

This study describes physicians' satisfaction with care for patients with depression before and after the implementation of a primary care-based collaborative care program.

METHOD

Project Improving Mood, Promoting Access to Collaborative Treatment for late-life depression (IMPACT) is a multisite, randomized controlled trial comparing a primary care-based collaborative disease management program for late-life depression with care as usual. A total of 450 primary care physicians at 18 participating clinics participated in a satisfaction survey before and 12 months after IMPACT initiation. The preintervention survey focused on physicians' satisfaction with current mental health resources and ability to provide depression care. The postintervention survey repeated these and added questions about physician's experience with the IMPACT collaborative care model.

RESULTS

Before intervention, about half (54%) of the participating physicians were satisfied with resources to treat patients with depression. After intervention, more than 90% reported the intervention as helpful in treating patients with depression and 82% felt that the intervention improved patients' clinical outcomes. Participating physicians identified proactive patient follow-up and patient education as the most helpful components of the IMPACT model.

CONCLUSIONS

Physicians perceived a substantial need for improving depression treatment in primary care. They were very satisfied with the IMPACT collaborative care model for treating depressed older adults and felt that similar care management models would also be helpful for treating other chronic medical illnesses.

Do too many shots due lead to missed vaccination opportunities? Does it matter?

BACKGROUND

Missed childhood vaccination opportunities have been generally described, yet not since the immunization schedule's recent rapid expansion. Little is known about the relationship between the number of vaccine doses due and whether all scheduled doses are administered, and the effect of dose deferral on immunization coverage.

METHODS

32 private pediatrics centers reviewed medical records covering the first 2 years of life for 858 patients. For each visit during ages 2-8 months, we determined the numbers of vaccine doses due versus administered. Logistic regression was used to assess the effect of dose deferral on immunization coverage at ages 1 and 2 years.

RESULTS

Of 2224 visits during ages 2-8 months at which > or =1 dose was administered, > or =1 due dose was deferred at 26%, 34%, and 48% of the visits at which < or =3, 4, and 5 doses were due, respectively. Absence of a deferred dose visit predicted increased coverage at age 1 (adjusted odds ratio: 2.4, 95% confidence interval: 1.8-3.2) and 2 years (2.1, 1.4-3.0).

CONCLUSIONS

Administering some but not all vaccine doses at visits during ages 2-8 months impairs immunization coverage through age 2 years.