referencje:

  1. O’Brien KL, et al. Burden of disease caused by Streptococcus pneumoniae in children younger than 5 years: global estimates. Lancet 2009;374:893–902.;
  2. Centers for Disease Control and Prevention. Epidemiology and Prevention of Vaccine-Preventable Diseases, 13th ed. 2015. www.cdc.gov/vaccines/pubs/pinkbook/downloads/pneumo.pdf (dostęp z dn. 07.08.2017).;