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Levels of diphtheria and tetanus specific IgG of Portuguese adult women, before and after vaccination with adult type Td. Duration of immunity following vaccination.

Gonçalves G, Santos MA, Frade JG, Cunha JS - BMC Public Health (2007)

Bottom Line: Among the 66 women who began vaccination in adolescence and adulthood (Group B), with monovalent TT, ATT IgG levels decreased with age at first dose (p < 0.001) and with time since last vaccination (p = 0.041).Among women not vaccinated with diphtheria toxoid, ADT IgG levels decreased with age.This also seems to apply to protection against diphtheria, but issues on the herd immunity and on the circulation of toxigenic strains need to be better understood.

View Article: PubMed Central - HTML - PubMed

Affiliation: Instituto Gulbenkian de Ciência, Oeiras, Portugal. guilherme.casa@mail.telepac.pt

ABSTRACT

Background: The need for tetanus toxoid decennial booster doses has been questioned by some experts. Several counter arguments have been presented, supporting the maintenance of decennial adult booster doses with tetanus and diphtheria toxoids (adult formulation of the vaccine: Td). This study aimed to evaluate the use of Td in Portuguese adult women under routine conditions. For that purpose we selected a group of women 30+ years of age to which vaccination was recommended. We intended to know if pre-vaccination antibody concentrations were associated with factors as age at first and last vaccination, number of doses and time since last revaccination. We also intended to assess the serological efficacy of Td booster.

Methods: Following the Portuguese guidelines 100 women were vaccinated with Td. Antitetanus toxin IgG (ATT IgG) and antidiphtheria toxin IgG (ADT IgG) levels were measured (mIU/ml) in 100 pre-vaccination and 91 post-vaccination sera. Detailed vaccination records were available from 88 participants.

Results: Twenty-two women (Group A) began vaccination with DPT/DT in their early childhood and their pre-vaccination ATT IgG levels increased with the number of doses received (p = 0.022) and decreased with time since last vaccination (p = 0.016). Among the 66 women who began vaccination in adolescence and adulthood (Group B), with monovalent TT, ATT IgG levels decreased with age at first dose (p < 0.001) and with time since last vaccination (p = 0.041). In Group A, antidiphtheria toxin IgG kinetics was very similar to that observed for ATT IgG. Among women not vaccinated with diphtheria toxoid, ADT IgG levels decreased with age. Serological response to both components of Td was good but more pronounced for ATT IgG.

Conclusion: Our study suggests that, to protect against tetanus, there is no need to administer decennial boosters to the Portuguese adults who have complied with the childhood/adolescent schedule (6 doses of tetanus toxoid). The adult booster intervals could be wider, probably of 20 years. This also seems to apply to protection against diphtheria, but issues on the herd immunity and on the circulation of toxigenic strains need to be better understood.

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Related in: MedlinePlus

Antidiphtheria toxin IgG (ADT IgG) levels, by number of doses of diphtheria-toxoid administered, in pre-vaccination sera of women who had been vaccinated with diphtheria-toxoid (Group A). Regression line (stippled) and threshold level of 100 mIU/ml.
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Figure 7: Antidiphtheria toxin IgG (ADT IgG) levels, by number of doses of diphtheria-toxoid administered, in pre-vaccination sera of women who had been vaccinated with diphtheria-toxoid (Group A). Regression line (stippled) and threshold level of 100 mIU/ml.

Mentions: Among the 22 women who had received diphtheria toxoid (Group A), on univariate analysis, ADT IgG levels increased with the number of doses of diphtheria toxoid received (Fig. 7; p = 0.013); all women who had received 6+ doses were immune. On univariate analysis ADT IgG levels were also associated with time since last dose (Fig. 8; p = 0.028) (in the case of diphtheria antibodies there was no need for log transformation of this variable); all susceptible women had received diphtheria toxoid more than 25 years before. It was not possible to assess the relative weight of these two independent variables because they were highly correlated with each other: women receiving fewer doses were the ones that had received the last dose longer ago. Present age was not associated with ADT IgG levels.


Levels of diphtheria and tetanus specific IgG of Portuguese adult women, before and after vaccination with adult type Td. Duration of immunity following vaccination.

Gonçalves G, Santos MA, Frade JG, Cunha JS - BMC Public Health (2007)

Antidiphtheria toxin IgG (ADT IgG) levels, by number of doses of diphtheria-toxoid administered, in pre-vaccination sera of women who had been vaccinated with diphtheria-toxoid (Group A). Regression line (stippled) and threshold level of 100 mIU/ml.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC1904210&req=5

Figure 7: Antidiphtheria toxin IgG (ADT IgG) levels, by number of doses of diphtheria-toxoid administered, in pre-vaccination sera of women who had been vaccinated with diphtheria-toxoid (Group A). Regression line (stippled) and threshold level of 100 mIU/ml.
Mentions: Among the 22 women who had received diphtheria toxoid (Group A), on univariate analysis, ADT IgG levels increased with the number of doses of diphtheria toxoid received (Fig. 7; p = 0.013); all women who had received 6+ doses were immune. On univariate analysis ADT IgG levels were also associated with time since last dose (Fig. 8; p = 0.028) (in the case of diphtheria antibodies there was no need for log transformation of this variable); all susceptible women had received diphtheria toxoid more than 25 years before. It was not possible to assess the relative weight of these two independent variables because they were highly correlated with each other: women receiving fewer doses were the ones that had received the last dose longer ago. Present age was not associated with ADT IgG levels.

Bottom Line: Among the 66 women who began vaccination in adolescence and adulthood (Group B), with monovalent TT, ATT IgG levels decreased with age at first dose (p < 0.001) and with time since last vaccination (p = 0.041).Among women not vaccinated with diphtheria toxoid, ADT IgG levels decreased with age.This also seems to apply to protection against diphtheria, but issues on the herd immunity and on the circulation of toxigenic strains need to be better understood.

View Article: PubMed Central - HTML - PubMed

Affiliation: Instituto Gulbenkian de Ciência, Oeiras, Portugal. guilherme.casa@mail.telepac.pt

ABSTRACT

Background: The need for tetanus toxoid decennial booster doses has been questioned by some experts. Several counter arguments have been presented, supporting the maintenance of decennial adult booster doses with tetanus and diphtheria toxoids (adult formulation of the vaccine: Td). This study aimed to evaluate the use of Td in Portuguese adult women under routine conditions. For that purpose we selected a group of women 30+ years of age to which vaccination was recommended. We intended to know if pre-vaccination antibody concentrations were associated with factors as age at first and last vaccination, number of doses and time since last revaccination. We also intended to assess the serological efficacy of Td booster.

Methods: Following the Portuguese guidelines 100 women were vaccinated with Td. Antitetanus toxin IgG (ATT IgG) and antidiphtheria toxin IgG (ADT IgG) levels were measured (mIU/ml) in 100 pre-vaccination and 91 post-vaccination sera. Detailed vaccination records were available from 88 participants.

Results: Twenty-two women (Group A) began vaccination with DPT/DT in their early childhood and their pre-vaccination ATT IgG levels increased with the number of doses received (p = 0.022) and decreased with time since last vaccination (p = 0.016). Among the 66 women who began vaccination in adolescence and adulthood (Group B), with monovalent TT, ATT IgG levels decreased with age at first dose (p < 0.001) and with time since last vaccination (p = 0.041). In Group A, antidiphtheria toxin IgG kinetics was very similar to that observed for ATT IgG. Among women not vaccinated with diphtheria toxoid, ADT IgG levels decreased with age. Serological response to both components of Td was good but more pronounced for ATT IgG.

Conclusion: Our study suggests that, to protect against tetanus, there is no need to administer decennial boosters to the Portuguese adults who have complied with the childhood/adolescent schedule (6 doses of tetanus toxoid). The adult booster intervals could be wider, probably of 20 years. This also seems to apply to protection against diphtheria, but issues on the herd immunity and on the circulation of toxigenic strains need to be better understood.

Show MeSH
Related in: MedlinePlus