Comment on

• A randomized, prospective field trial of a conjugate vaccine in the protection of infants and young children against invasive Haemophilus influenzae type b disease.

  Eskola J, Käyhty H, Takala AK, Peltola H, Rönnberg PR, Kela E, Pekkanen E, McVerry PH, Mäkelä PH. Eskola J, et al. N Engl J Med. 1990 Nov 15;323(20):1381-7. doi: 10.1056/NEJM199011153232004. N Engl J Med. 1990. PMID: 2233904 Clinical Trial.
• Impaired antibody response to Haemophilus influenzae type b polysaccharide and low IgG2 and IgG4 concentrations in Apache children.

  Siber GR, Santosham M, Reid GR, Thompson C, Almeido-Hill J, Morell A, deLange G, Ketcham JK, Callahan EH. Siber GR, et al. N Engl J Med. 1990 Nov 15;323(20):1387-92. doi: 10.1056/NEJM199011153232005. N Engl J Med. 1990. PMID: 2233905
• Limited efficacy of a Haemophilus influenzae type b conjugate vaccine in Alaska Native infants. The Alaska H. influenzae Vaccine Study Group.

  Ward J, Brenneman G, Letson GW, Heyward WL. Ward J, et al. N Engl J Med. 1990 Nov 15;323(20):1393-401. doi: 10.1056/NEJM199011153232006. N Engl J Med. 1990. PMID: 2233906 Clinical Trial.