In this randomized trial in subjects between 15 and 65 years old, a new acellular pertussis vaccine was safe and had an efficacy of 92 percent against documented, symptomatic
Bordetella pertussis
...infections. Among controls, the incidence of pertussis was 370 per 100,000 person-years. Vaccination of adults and adolescents could prevent pertussis and reduce the transmission of
B. pertussis
to young children.
In subjects between 15 and 65 years old, a new acellular pertussis vaccine was safe and had an efficacy of 92 percent against documented, symptomatic
Bordetella pertussis
infections.
Bordetella pertussis
infects the human respiratory tract and in nonimmune persons causes whooping cough, a severe illness associated with prolonged cough.
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The severity of illness varies with age, immune status (prior immunization or infection), and probably such factors as the extent of exposure and the virulence of the organism. Disease risk and severity are greatest in unimmunized infants.
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–
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During the past 50 years, routine pediatric pertussis immunization has dramatically decreased the pediatric disease burden.
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In the United States, the annual incidence of pertussis fell from 157 per 100,000 persons in the prevaccine era to less than 1 . . .
Background. Acellular pertussis (aP) booster immunizations have been recommended for adolescents and older persons to enhance long-term protection and to possibly reduce community transmission of ...infections. Methods. This was a multicenter, randomized, double-blind vaccine trial in which one-half of the subjects received aP vaccine and one-half received hepatitis A vaccine (control subjects). All subjects were observed for almost 2 years for cough illnesses, and all underwent microbiologic and serologic studies for detection of pertussis infection. Immunoglobulin G (IgG) and immunoglobulin A (IgA) antibodies to pertussis toxin, filamentous hemagglutinin, pertactin, and fimbriae 2/3 were measured by enzyme-linked immunosorbent assay in serum samples obtained 1 and 12 months after immunization. Infection rates were determined with a variety of serologic criteria for control and vaccinated subjects. The incidence of prolonged cough illness was ascertained for subjects with and subjects without serologic evidence of infection. Results. Infection rates among control subjects are particularly representative of those in nonimmunized adults. Among control subjects, 0.4%–2.7% had increases in pertussis antibody of various types and degrees over 1 year, and 20%–46% had prolonged cough illnesses during this interval. Pertussis toxin antibody had the greatest specificity for detecting increases in antibody levels. Asymptomatic infections were ∼5 times more common than clinical illnesses that met a strict clinical and microbiologic case definition. Relative to control subjects, aP-immunized subjects may have fewer increases in the antibody level (i.e., infections), especially for antibodies to fimbriae 2/3 (an antigen not in the vaccine). Conclusions. Pertussis infections in older persons are largely asymptomatic. aP boosters confer protection for adolescents and adults against symptomatic pertussis and likely confer protection against mild and asymptomatic infections, and use of boosters may reduce transmission to others, especially infants.
As part of a prospective acellular pertussis (ACP) vaccine efficacy trial, 5 serum samples were obtained, over an 18-month period, from 101 ACP-vaccine recipients and 99 control subjects, to assess ...ACP antibody response and decay. Immunoglobulin (Ig) G and IgA antibodies to pertussis toxin (PT), filamentous hemagglutinin (FHA), pertactin (PRN), and fimbriae 2/3 (FIM) were measured by enzyme-linked immunosorbant assay, and titers of agglutinin were determined. Of the subjects, 16%–19% had preimmunization values of antibodies to PT that were above the assay's limit of quantitation (LOQ); in contrast, 36%–63% of the subjects had preimmunization values of antibodies to FHA, PRN, or FIM that were above the LOQ. Substantial increases in titers of IgG and IgA antibodies to the 3 ACP antigens (PT, FHA, and PRN) were observed. Over the 18-months, the percent decay in IgG and IgA antibodies ranged from 56% to 73% and from 57% to 70%, respectively; the IgG antibody response and decay suggests that geometric mean titers likely remain above the LOQ for 2–9 years and above the threshold of detection for 4–13 years. These findings support the use of ACP booster immunizations for adolescents and adults, to provide sustained levels of antibody.
Infants were immunized with 1 of the 3 experimental pneumococcal conjugate vaccines that contain 6B and 19F but not 6A or 19A serotypes. Their sera were studied for the capacity to opsonize ...Streptococcus pneumoniae 6A, 6B, 19A, and 19F serotypes and the level of IgG antibody to the 4 serotypes. Significant increases were observed in the number of infants with detectable opsonophagocytic titers with 3 conjugate vaccines for 6B (vaccine) serotype but with only 2 vaccines for 6A (cross-reactive) serotype. Significant increases were observed with 2 conjugate vaccines for 19F serotype but with only 1 vaccine for 19A serotype. Thus, some conjugate vaccines may elicit cross-protection better than others. In addition, correlations between opsonophagocytic titers and IgG antibody levels by ELISA were high for 6B and 19F serotypes but low for 6A and 19A serotypes. Thus, ELISA may be an inadequate surrogate assay of vaccine response for cross-reactive serotypes.
Serum specimens were obtained from all subjects in the adolescent and adult acellular pertussis (aP) vaccine efficacy trial before and after immunization to study the prevalence of IgG and IgA ...antibody and geometric mean titers to 4 Bordetella pertussis antigens. Of 1793 adolescents and adult subjects who received aP vaccine, only 20%, 68%, 59%, and 39% had concentrations of IgG antibodies to pertussis toxin, filamentous hemagglutinin, pertactin, and fimbriae types 2 and 3, respectively, that were greater than or equal to the limit of quantitation of the enzyme-linked immunosorbent assay used in the analysis. There was minimal variation in antibody prevalence with respect to geographic area, age, sex, or race.
Reply to Baughman et al Ward, Joel I.; Cherry, James D.; Lee, Martin ...
Clinical infectious diseases,
01/2007, Letnik:
44, Številka:
1
Journal Article
We conducted a seroepidemiologic study to evaluate the kinetics of maternal hepatitis A antibody decay in infants. Serum samples obtained from 200 infants at 2 and 4 months of age were tested for ...hepatitis A antibody. Seventy-six infants (38%) were hepatitis A antibody-positive with a geometric mean antibody titer of 2634 mIU/ml. Samples collected at 4, 6 and/or 12 months of age showed seropositivity rates of 100, 95 and 39%, respectively. These data indicate that maternal antibody levels remained high through the first 6 months of life but decayed significantly by 12 months of age.
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