New Method For Delivering Infant Vaccines Identified

Improving pediatric vaccine efficacy could reduce both the age of administration and the need for multiple booster injections

new born crying

Two million infants die each year from infectious diseases before they reach 12 months, many of these diseases are vaccine preventable in older populations.

Young babies and infants are limited in their ability to produce an immune response to infection as well as in response to vaccines. An individual’s innate immune system isn’t fully developed until puberty.

Therefore, in order to complement the developing immune system of a baby, vaccines are given across a 13-month period.

This means the infant is vulnerable to the vaccine-targeted diseases before the necessary vaccine is given.

To address this massive health issue, scientists at Trinity University Dublin, in Ireland, may have discovered a revolutionary way to administer vaccines to infants and newborns. 

Their new research published in The Journal of Immunology aims to find an adjuvant that kick-starts the immature infant’s immune system. Adjuvants instruct the immune system to mount a response to the infection. “Many adjuvants used in vaccines today were developed in adults.” “However, babies and children are not simply little adults, and because of this, a child’s immune system responds differently to that of an adult.

Dr. Kiva Brennan, a Research Fellow in Trinity’s School of Medicine, and her research team have revealed a strong immune response in newborns to cytosolic nucleic acid (CNA).

Dr. Brennan’s team observed that the CNA sensors induced “robust antiviral and pro-inflammatory pathways”.

They showed that in direct contrast to weak TLR-induced type I IFN in human cord blood mononuclear cells, cord blood mononuclear cells are capable of initiating a potent response to CNA, inducing both antiviral type I IFN and, unexpectedly, proinflammatory TNF-α.

A deficiency in Rab11-GTPase endosome formation and consequent lack of IRF3 activation in neonatal monocytes is at least in part responsible for the marked disparity in TLR-induced IFN production between neonatal and adult monocytes.

CNA receptors do not rely on endosome formation, and therefore, these responses remain intact in neonates.

Heightened neonatal responses to CNA challenge are maintained in children up to 2 years of age and, in marked contrast to TLR4/9 agonists, result in IL-12p70 and IFN-γ generation.

CNA sensors induce robust antiviral and proinflammatory pathways in neonates and children and possess great potential for use as immunostimulants or vaccine adjuvants for targeted neonatal and pediatric populations to promote cell-mediated immunity against invasive infectious disease.

This strong response demonstrated by Brennan’s team indicates that vaccines could be given at an earlier age despite the baby’s less developed immune system while mounting the same effective immune response.

Dr. Sarah Doyle, a senior author and Assistant Professor in Immunology at Trinity, said in a press release, “Improving pediatric vaccine efficacy has the potential to reduce both the age of administration and the need for multiple booster injections, likely increasing compliance and protecting more of the pediatric population with fewer doctors’ visit.

This work was supported by The National Children’s Research Centre, Health Research Board HRA_PHR/2013/290, and Science Foundation Ireland 15/CDA/3497. No conflicts of interest were disclosed.