Abstract: In a first aspect, the present invention relates to cyclic dinucleotide compounds, in particular, c-di AMP for use in a method of inducing or promoting an immune response in an individual wherein said individual is a neonate or infant. The compound according to the present invention is particularly useful for use in therapeutic or prophylactic vaccination. In a further aspect, pharmaceutical compositions comprising the compound according to the present invention as an adjuvant, a pharmaceutically active ingredient for use as defined herein, in particular, as an adjuvant in a vaccine for unborn children, neonates and infants are provided. Finally, the present invention relates to a kit comprising a compound according to the present invention as an adjuvant, an antigen comprising antigenic structure as active vaccination component, in particular, to the use of said kit in a use of preventing or treating a disease.