Haemophilus influenzae type b immunization in infants in the United Kingdom: effects of diphtheria/tetanus/acellular pertussis/Hib combination vaccine, significant prematurity, and a fourth dose.

Abstract

OBJECTIVE:

To measure anti-polyribosylribitolphosphate (PRP) antibody and anti-tetanus toxoid (TT) antibody responses in UK infants to explore the effects of (1) immunization with an acellular diphtheria/tetanus/pertussis/Haemophilus influenzae type b (DTPHib) combination vaccine, (2) significant preterm delivery, and (3) a fourth dose of conjugated Hib vaccine (PRP-T) in those with a low anti-PRP antibody (<1.0 microg/mL) after primary immunization.

METHODS:

A prospective study was conducted in 4 tertiary neonatal units at a time when 2 types of DTPHib vaccines were used interchangeably in the United Kingdom for primary immunization: acellular (DTPaHib) and whole cell. Timing and type of all vaccine doses were as per standard UK practice. Blood was taken before and after immunization. A total of 166 preterm and 45 term infants completed the study; 97 (15 term) infants who had anti-PRP antibody <1.0 microg/mL were offered a fourth dose of PRP-T; 61 (55 preterm) then had repeat antibody measurements. Anti-PRP and anti-TT antibody after primary immunization relative to gestation and number of whole cell vaccine doses received was measured, as well as anti-PRP antibody after a fourth dose of PRP-T.

RESULTS:

A total of 49% of preterm and 33% of term infants had anti-PRP antibody <1.0 microg/mL after full primary immunization. Receipt of 1 or more acellular vaccine doses was associated with lower anti-PRP antibody, a dose response effect being observed. Preterm infants were less likely to have anti-PRP antibody >1.0 microg/mL compared with term infants. A total of 93% of infants who were given a fourth dose had anti-PRP antibody >1.0 microg/mL. Anti-TT antibody responses were satisfactory for all infants but also reduced by each DTPaHib dose received.

CONCLUSION:

Infants who receive DTPaHib, are significantly preterm, or who do not receive a fourth dose of conjugated Hib vaccine may be at increased risk for Hib disease.

• Authors: Janet E Berrington, Andrew J Cant, John N S Matthews, Marilyn O'Keeffe, Gavin P Spickett, Alan C Fenton
• Journal: Pediatrics (Pediatrics) Vol. 117 Issue 4 Pg. e717-24 (Apr 2006) ISSN: 1098-4275 [Electronic] United States
• PMID: 16549502 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Antibodies, Bacterial
• Diphtheria-Tetanus-acellular Pertussis Vaccines
• Haemophilus Vaccines
• Haemophilus influenza type b polysaccharide vaccine-tetanus toxin conjugate
• Haemophilus influenzae type b polysaccharide vaccine
• Polysaccharides
• Polysaccharides, Bacterial
• Tetanus Toxoid
• Vaccines, Combined
• Vaccines, Conjugate
• polyribitol phosphate

Topics

• Antibodies, Bacterial (immunology)
• Bacterial Capsules
• Diphtheria-Tetanus-acellular Pertussis Vaccines (immunology)
• Dose-Response Relationship, Immunologic
• Haemophilus Infections (prevention & control)
• Haemophilus Vaccines (administration & dosage, immunology)
• Haemophilus influenzae type b (immunology)
• Humans
• Immunization
• Immunization, Secondary
• Infant, Newborn
• Infant, Premature (immunology)
• Polysaccharides (immunology)
• Polysaccharides, Bacterial (immunology)
• Tetanus Toxoid (administration & dosage, immunology)
• Vaccines, Combined
• Vaccines, Conjugate