Special immunization considerations of the preterm infant

Vaccinations in Infants Born Preterm: An Update

Infants born prematurely (before completion of 37 weeks of gestation) are at increased risk of morbidity and mortality due to vaccine preventable diseases, mostly because of their immunological immaturity and failure of transfer of maternal protective antibodies. Despite their great need of being vaccinated, concerns on vaccine safety and efficacy, constitute the main reasons for which vaccinations are often delayed in this group. In this review we summarize the latest evidence on vaccine safety, efficacy and immunogenicity in preterm infants which is similar to full-term infants. Therefore there is no reason for delaying vaccination in this population.

Update on vaccination of preterm infants: a systematic review about safety and efficacy/effectiveness. Proposal for a position statement by Italian Society of Pediatric Allergology and Immunology jointly with the Italian Society of Neonatology

INTRODUCTION

Preterm infants (PIs) are at increased risk of vaccine-preventable diseases (VPDs). However, delayed vaccination start and low vaccine coverage are still reported. Areas covered: This systematic review includes 37 articles on preterm vaccination published in 2008-2018 in PubMed. Both live attenuated and inactivated vaccines are safe and well tolerated in PIs. Local reactions, apnea, and reactivity changes are the most frequently reported adverse events. Lower gestational age and birth weight, preimmunization apnea, longer use of continuous positive airway pressure (CPAP) are risk factors for apnea. The proportion of PIs who develop protective humoral and cellular immunity is generally similar to full terms although later gestational age is associated with increased antibody IgG concentrations (i.e. against certain pneumococcal serotypes, influenza, hepatitis B virus and poliovirus 1) and increased mononuclear cells proliferation (i.e. after inactivated poliovirus). Expert opinion: PIs can be safely and adequately protected by available vaccines with the same schedule used for full terms. Data at this regard have been retrieved by studies using a 3-dose primary series for pneumococcal and hexavalent vaccines. Further studies are needed regarding the 2 + 1 schedule. Apnea represents a nonspecific stress response in PIs, thus those hospitalized at 2 months should have cardio-respiratory monitoring after their first vaccination.

Immunization Status of NICU Graduates at a Tertiary Care Children's Hospital

BACKGROUND

Approximately 500,000 infants are born prematurely each year in the United States. Immunization of infants in a neonatal intensive care unit (NICU) set a precedence for future immunizations.

PURPOSES

The objectives of this study were to determine the current rates of immunization and identify variables associated with immunizations of NICU graduates who were aged 60 days or older at time of discharge.

METHODS

This descriptive pilot study utilized retrospective paper medical record review in one tertiary children's hospital. The relationships between immunization status and study variables were examined using t tests and logistic regression.

RESULTS

Of 43 infants discharged at least 60 days of age or older from the NICU, 74.4% were fully immunized in accordance with American Academy of Pediatrics (AAP) recommendations. Significant predictors were age at discharge for immunization and steroid use for nonimmunization.

IMPLICATIONS FOR PRACTICE

Immunization needs to be a priority in order to give NICU infants every advantage regarding their future health status. Nurses need to implement hospital policies ensuring immunizations of NICU graduates.

IMPLICATIONS FOR RESEARCH

Future studies should focus on samples from diverse hospitals and levels of NICUs. Qualitative studies exploring and describing parent and provider knowledge of current AAP guidelines will strengthen our understanding of potential barriers to immunization.

Adverse Events After Routine Immunization of Extremely Low-Birth-Weight Infants

IMPORTANCE

Immunization of extremely low-birth-weight (ELBW) infants in the neonatal intensive care unit (NICU) is associated with adverse events, including fever and apnea or bradycardia, in the immediate postimmunization period. These adverse events present a diagnostic dilemma for physicians, leading to the potential for immunization delay and sepsis evaluations.

OBJECTIVE

To compare the incidence of sepsis evaluations, need for increased respiratory support, intubation, seizures, and death among immunized ELBW infants in the 3 days before and after immunization.

DESIGN, SETTING, AND PARTICIPANTS

In this multicenter retrospective cohort study, we studied 13,926 ELBW infants born at 28 weeks' gestation or less who were discharged from January 1, 2007, through December 31, 2012, from 348 NICUs managed by the Pediatrix Medical Group.

EXPOSURES

At least one immunization between the ages of 53 and 110 days.

MAIN OUTCOMES AND MEASURES

Incidence of sepsis evaluations, need for increased respiratory support, intubation, seizures, and death.

RESULTS

Most of the 13,926 infants (91.2%) received 3 or more immunizations. The incidence of sepsis evaluations increased from 5.4 per 1000 patient-days in the preimmunization period to 19.3 per 1000 patient-days in the postimmunization period (adjusted rate ratio [ARR], 3.7; 95% CI, 3.2-4.4). The need for increased respiratory support increased from 6.6 per 1000 patient-days in the preimmunization period to 14.0 per 1000 patient-days in the postimmunization period (ARR, 2.1; 95% CI, 1.9-2.5), and intubation increased from 2.0 per 1000 patient-days to 3.6 per 1000 patient-days (ARR, 1.7; 95% CI, 1.3-2.2). The postimmunization incidence of adverse events was similar across immunization types, including combination vaccines when compared with single-dose vaccines. Infants who were born at 23 to 24 weeks' gestation had a higher risk of sepsis evaluation and intubation after immunization. A prior history of sepsis was associated with higher risk of sepsis evaluation after immunization.

CONCLUSIONS AND RELEVANCE

All ELBW infants in the NICU had an increased incidence of sepsis evaluations and increased respiratory support and intubation after routine immunization. Our findings provide no evidence to suggest that physicians should not use combination vaccines in ELBW infants. Further studies are needed to determine whether timing or spacing of immunization administrations confers risk for the developing adverse events and whether a prior history of sepsis confers risk for an altered immune response in ELBW infants.

Update on immunizations commonly used in the NICU

With few exceptions, it is currently recommended that all premature infants should receive routine childhood vaccines at the same chronologic age as term infants. Thus, neonatal nurses need to stay current on the recommendations for immunizations commonly used in the NICU setting. It is important for nurses to provide information that is reliable and verifiable with scientific evidence to the parents.