Limits...
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.

Show MeSH

Related in: MedlinePlus

Antitetanus toxin IgG (ATT IgG) levels in pre-vaccination sera, by age at first dose of tetanus-toxoid received in women who began vaccination with TT (Group B). Regression line (stippled) and threshold level of 160 mIU/ml.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC1904210&req=5

Figure 4: Antitetanus toxin IgG (ATT IgG) levels in pre-vaccination sera, by age at first dose of tetanus-toxoid received in women who began vaccination with TT (Group B). Regression line (stippled) and threshold level of 160 mIU/ml.

Mentions: In Group B (those who began vaccination with TT), on univariate analysis, ATT IgG levels decreased with time elapsed since last dose (log transformed variable) (Fig. 3; p = 0.007). The levels of ATT IgG were not dependent (p = 0.376) on the number of doses of tetanus toxoid received, but all susceptible women (n = 9) had received less than 4 doses of tetanus toxoid; on the other hand, 8 out of the 9 women who had received 4+ doses of tetanus toxoid (Table 1) had received the last boost more than 10 years before. Furthermore, the decrease of ATT IgG levels with time since last dose was only significant for those who had received 3+ doses. ATT IgG levels were inversely associated with the age at first vaccination (p < 0.001); all 9 women susceptible to tetanus had received the first dose of tetanus toxoid after the age of 33 years (Fig. 4). On univariate analysis, present age and age at last dose were also significantly associated with ATT IgG levels (Table 3) but they were dropped from the final model because of the confounding effect of age at first vaccination. The final model explained 32% of variability of ATT IgG levels and included age at first vaccination with tetanus toxoid and time since the last dose (Table 3).


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)

Antitetanus toxin IgG (ATT IgG) levels in pre-vaccination sera, by age at first dose of tetanus-toxoid received in women who began vaccination with TT (Group B). Regression line (stippled) and threshold level of 160 mIU/ml.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 4: Antitetanus toxin IgG (ATT IgG) levels in pre-vaccination sera, by age at first dose of tetanus-toxoid received in women who began vaccination with TT (Group B). Regression line (stippled) and threshold level of 160 mIU/ml.
Mentions: In Group B (those who began vaccination with TT), on univariate analysis, ATT IgG levels decreased with time elapsed since last dose (log transformed variable) (Fig. 3; p = 0.007). The levels of ATT IgG were not dependent (p = 0.376) on the number of doses of tetanus toxoid received, but all susceptible women (n = 9) had received less than 4 doses of tetanus toxoid; on the other hand, 8 out of the 9 women who had received 4+ doses of tetanus toxoid (Table 1) had received the last boost more than 10 years before. Furthermore, the decrease of ATT IgG levels with time since last dose was only significant for those who had received 3+ doses. ATT IgG levels were inversely associated with the age at first vaccination (p < 0.001); all 9 women susceptible to tetanus had received the first dose of tetanus toxoid after the age of 33 years (Fig. 4). On univariate analysis, present age and age at last dose were also significantly associated with ATT IgG levels (Table 3) but they were dropped from the final model because of the confounding effect of age at first vaccination. The final model explained 32% of variability of ATT IgG levels and included age at first vaccination with tetanus toxoid and time since the last dose (Table 3).

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