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Breast milk provides the immune support infants need in their first year of life1–3

The first year of life is a critical time for immune system development4,5

Initial immune protection provided by maternal antibodies declines rapidly after birth4,5

illustration-mom-baby illustration-mom-baby-m

What are the factors that influence early immune development?

Several factors can influence the development of an infant's immune system, from antibiotic intake during pregnancy to the natural source of microbes in the environment.6 Discover more information on how immunity is transferred from mother to infant.

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Breast milk contains several factors which help infants build their own immune system after birth:3

protein-signalsImmune signalling proteins

  • Cytokines (e.g. IL-1β, IL-5, IL-13)
  • Growth factors (e.g. epidermal growth factor, vascular endothelial growth factor)
  • Immunoglobulins (e.g. IgA, IgG, IgM)

immune-cellsImmune cells

  • Lymphocytes
  • Macrophages
  • Granulocytes

human-milkHuman milk oligosaccharides

  • Short- to medium-chain carbohydrates, e.g. 2’-fucosyllactose (2’-FL), the most abundant HMO in most mothers’ milk7

Find out how the third most abundant solid component of breast milk can support the immune system.

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Without the protective benefits of breast milk, formula-fed infants with CMA are more vulnerable to immune challenges, particularly in the first year of life2,8–12

Compared with exclusively breastfed infants, formula-fed infants face higher risks of:


50% increased risk of eczema9


260% increased risk of hospitalisation for lower respiratory infection10


Significantly elevated TNF-α and IL-2 serum levels (both p=0.002)2


CMA symptoms present in up to 7% of all infants vs 0.5% breastfed infants11,12


Formula-fed infants with CMA consume additional healthcare resources compared with formula-fed infants without CMA:

More hospital admissions8

(13% vs 5%)*†

More GP appointments8

(mean: 4.7 vs 3.1)*‡

More visits to out-of-hours care8

(24% vs 15%)


IMPORTANT NOTICE: Breastfeeding is best for infants and is recommended for as long as possible during infancy. Alimentum and EleCare are infant formulas for special medical purposes and should only be used under the recommendation or guidance of a healthcare professional.

*Data from infants with CMA or suspected CMA (n=200) and infants who did not have CMA (n=200) and who were exclusively formula fed. Data from the first 12 months of life were collected through general practitioners; GPs did not indicate whether illness occurred before or after diagnosis.
Number of hospital admittances (does not have to include an overnight stay) related to skin, respiratory, and gastrointestinal disorders in the past 12 months.
Mean number of total GP appointments for medical issues related to skin, respiratory, and gastrointestinal disorders in the past 12 months.
§Number of attendances at A&E or out-of-hours urgent care related to skin, respiratory, and gastrointestinal disorders in the past 12 months.

2’-FL: 2’-fucosyllactose; CMA: cow’s milk allergy; GI: gastrointestinal; HMO: human milk oligosaccharide; IgA: immunoglobulin A; IgG: immunoglobulin G; IgM: immunoglobulin M; IL: interleukin; TNF: tumour necrosis factor; WHO: World Health Organization.



IE-SIMILAC-2100003 February 2021