Completeness and timeliness of diphtheria-tetanus-pertussis, measles-mumps-rubella, and polio vaccines in young children with chronic health conditions: A systematic review

Policy of vaccination of "fragile children": Results of a survey of 14 Italian children's hospitals

Children with chronic disease are at higher risk of invasive infectious disease, including several vaccine-preventable infections. The Italian Association of Pediatric Hospitals (AOPI) carried out a survey of immunization practices: 14/16 AOPI hospitals completed the survey; 50% of them include 100-199 beds, while 21% have <100 beds. In 12/14 hospitals (86%) all vaccinations included in the National Immunization Plan (plus influenza e COVID-19 vaccines) are available for inpatients, in selected wards (n = 4), on single pediatrician initiative (n = 3), by a centralized in-hospital immunization service (n = 2), and the remaining 3 in a "protected vaccination area" or in a COVID-19 pathway. The wards in which vaccination is more frequently offered to in-patients are: General Pediatrics, Neonatology, Pediatric Hematology & Oncology, Pediatric Diabetology, Pediatric Cardiology, and Pediatric Infectious Diseases (range, 58% to 83%). In 58% of vaccinating hospitals, <500 vaccinations/year are reported, while in 17% this number is >2,000/year. A COVID-19 vaccination team is in place for any inpatient child older than 12 years in 42% of hospitals, in 42% only for "fragile" children. A centralized in-hospital immunization service is an emerging model that may contribute to increase compliance to vaccination of fragile patients and to fight against vaccination hesitancy.

Immunizations in Children With Chronic Diseases: A State of the Science Review With Implications for Practice Change

INTRODUCTION

Chronic diseases afflict more than 25% of America's children, and it has been reported that some children with chronic illness are underimmunized, compounding their risks of complications from vaccine-preventable infections.

METHOD

To better assess vaccination rates in this population, we systematically reviewed PubMed and CINAHL. Publications were included if specific to immunization rates in U.S. children aged < 18 years and were published between 2010 and 2020. A total of 18 studies were reviewed.

RESULTS

Compared with healthy children, children with chronic illnesses have significantly lower vaccination rates, and they face higher risks if they contract a preventable disease.

DISCUSSION

Barriers to on-time vaccinations included inadequate education for both parents and providers and misconceptions from nonmedical sources. In addition, lack of provider comfort serves to lower vaccination rates of children with chronic illness. This topic requires further research and discussion until all children are protected from preventable illness.

Vaccination deferral among children with seizures in Zhejiang: influence, recommendation, safety and implications

OBJECTIVES

Delayed vaccination in children with seizures was common in China. This study aims to describe the vaccination status, reasons for vaccination deferral, vaccination recommendations and the safety for these patients in Zhejiang.

METHODS

1539 children included were divided into febrile seizure (FS) group, epilepsy (EP) group, unclassified seizure group and other symptomatic seizure group. Medical records and reasons for the vaccination deferral were collected by questionnaire. Vaccination data and Adverse Event Following Immunization were retrieved from vaccination booklets.

RESULTS

The main diseases of children enrolled were FS (756, 49.1%) and EP (443, 28.8%). Most of them (95.6%) were vaccinated on time before the onset of seizure, but their vaccination was delayed after seizure occurred. 76.1% were recommended to receive vaccines normally, of which the FS group accounted for the highest proportion (90.3%). 88.73% of them were vaccinated as recommended, and no serious side effects or seizure occurred. The main reason for vaccination deferral was providers' and parents' hesitation to have them vaccinated.

CONCLUSION

Seizures were overestimated as a contraindication for vaccination in China. Routine vaccination was safe in most circumstances. It is essential to educate providers and parents about the benefits and contraindications of vaccination in children with seizures.

In-hospital and web-based intervention to counteract vaccine hesitancy in very preterm infants' families: a NICU experience

BACKGROUND

Vaccine hesitancy is a global problem, carrying significant health risks for extremely vulnerable population as that of preterm infants. Social media are emerging as significant tools for public health promotion. Our aim was to evaluate both the coverage and the timeliness of routine immunizations in a cohort of preterm infants (< 33 weeks of gestational age) at 24 months of age whose families have been subjected to in-hospital and web-based interventions to counteract vaccine hesitancy.

METHODS

For a period of 2 years parents of preterm infants were instructed during their follow up visits by a member of the NICU team to get correct informations about vaccines from a social network page. Vaccination rates of preterm infants were assessed at 24 months of chronological age with an electronic database and compared to both general population and historical cohort.

RESULTS

Coverage and timeliness of vaccinations at 24 months of age of 170 preterm infants were analyzed in December 2019. Gestational age and birth weight median (IQR) were, respectively, 31.0 (5.0) weeks and 1475.0 (843.8) g. Coverage rates were similar to those of the regional population (p > 0.05), while timeliness of administration was significantly delayed compared to the recommended schedule (p < 0.001). Age of administration was not correlated with either body weight and gestational age at birth (Spearman rank, p > 0.05). DTaP-IPV-HBV-Hib 2nd and 3rd doses, MMR and Varicella vaccines coverage data were higher compared to historical cohort (p < 0.05).

CONCLUSION

Increasing vaccine confidence through web-based interventions could have a positive impact on vaccination acceptance of parents of preterm infants, although timeliness results still delayed. There is a strong need to develop different and effective vaccination strategies to protect this very vulnerable population.

Vaccine coverage among children with epilepsy in two Canadian provinces: A Canadian immunization research network study

OBJECTIVES

Children with epilepsy are at increased risk of complications from vaccine-preventable infections, yet information on vaccine coverage in these children is scarce. We aimed to compare vaccine coverage among children with epilepsy to children without epilepsy.

STUDY DESIGN

We conducted a retrospective cohort study including all 2005-2013 births in Manitoba and Ontario, Canada, creating two cohorts: 2-year-olds and 7-year-olds (followed to age 2 and 7 years). We split each cohort into epilepsy and non-epilepsy subcohorts. We assessed vaccination coverage based on provincial schedules and determined timeliness of MMR (measles, mumps, rubella) dose 1 (recommended at 12 months) and DTaP (diphtheria, tetanus, pertussis) dose 4 (recommended at 18 months). We used logistic regression to calculate adjusted odds ratios (aORs) of the association between epilepsy and vaccination, combining both provincial estimates using random effects meta-analysis.

RESULTS

We included 16,558 2-year-olds (Manitoba, 653; Ontario, 15,905) and 13,004 7-year-olds (Manitoba, 483; Ontario, 12,521) with epilepsy. At age 2 years, the aOR for up-to-date vaccination among children with versus without epilepsy was 0.9 (95% confidence interval 0.8-1.1); at age 7 years it was 1.0 (0.9-1.1). Infants diagnosed with epilepsy before age 6 months were less likely to be up-to-date at age 2 years (0.9; 0.8-0.9), although this difference disappeared by age 7 years. Vaccine timeliness was similar between children with and without epilepsy for MMR dose 1 and DTaP dose 4.

CONCLUSIONS

Overall, this study suggests that children with epilepsy are not significantly under-vaccinated compared to their peers without epilepsy. As children with epilepsy are at a higher risk of complications from vaccine-preventable diseases, vaccination in children with epilepsy should be optimized, especially early in life, as these children may not be able to rely on herd protection.

Vaccine Adjuvants Derived from Marine Organisms

Vaccine adjuvants help to enhance the immunogenicity of weak antigens. The adjuvant effect of certain substances was noted long ago (the 40s of the last century), and since then a large number of adjuvants belonging to different groups of chemicals have been studied. This review presents research data on the nonspecific action of substances originated from marine organisms, their derivatives and complexes, united by the name 'adjuvants'. There are covered the mechanisms of their action, safety, as well as the practical use of adjuvants derived from marine hydrobionts in medical immunology and veterinary medicine to create modern vaccines that should be non-toxic and efficient. The present review is intended to briefly describe some important achievements in the use of marine resources to solve this important problem.