 The purpose of this study is to assess the efficacy in young children in preventing acute otitis media due to vaccine serotype pneumococcal or non typable Hemophilus influenza, following immunization with an 11-valent pneumococcal vaccine according to a 3 dose primary vaccination in the first year of life, with booster dose in the second year of life. Prophylactic immunization with pneumococcal conjugate vaccine is compared to placebo hepatitis A vaccine. 