Safety, immunogenicity and an open, retrospective study of efficacy of a monocomponent pertussis toxoid vaccine in infants.
One hundred forty-five infants were vaccinated with 25 micrograms of pertussis toxoid (NICHD-Ptxd) at 3, 5 and 7 or at 3, 5 and 12 months of age. One month after the third vaccination all had high serum IgG and neutralizing antibodies (antitoxin) against pertussis toxin. Vaccination at 3, 5 and 12 months resulted in higher antibody titers than vaccination at 3, 5 and 7 months. Sera obtained from 109 children at 3 years of age showed a decline of antibodies, but all had detectable antibodies. Adverse reactions were confined to local redness and swelling, which exceeded 2 cm after 17% of all injections. When the children were 3 years old, a comparison was made of the incidence of clinical pertussis in 142 of the 145 vaccinated children and in 284 age-matched controls living in the same areas. Information on symptoms of pertussis was obtained from the parents during telephone interviews. None of the vaccinated children had clinical pertussis, defined as a 6-week course of paroxysmal cough with whooping attacks or vomiting, whereas 57 controls (20%) had experienced these symptoms. Sixteen vaccinated children were exposed to pertussis in the household. Two of them had laboratory-verified Bordetella pertussis infections with cough of 2 and 4 weeks, respectively, without whooping attacks or vomiting, whereas 14 did not develop a cough. The study shows that NICHD-Ptxd is immunogenic in infants and that it most likely confers a high degree of protection against pertussis.
Isacson
J
J
Department of Pediatrics, University of Göteborg, Sweden.
Trollfors
B
B
Taranger
J
J
MacDowall
I
I
Johansson
J
J
Lagergård
T
T
Robbins
J B
JB
D000907:Antibodies, Bacterial / Q000097:blood; D001886:Bordetella pertussis / Q000276:immunology; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007223:Infant; D008297:Male; D010567:Pertussis Vaccine / Q000008:administration & dosage* / Q000009:adverse effects; D012189:Retrospective Studies; D016896:Treatment Outcome; D014917:Whooping Cough / Q000097:blood / Q000276:immunology / Q000517:prevention & control*
D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D010567:Pertussis Vaccine