Vaccines (Oct 2019)

Factors Influencing Persistence of Diphtheria Immunity and Immune Response to a Booster Dose in Healthy Slovak Adults

  • Marek Petráš,
  • Vladimir Oleár,
  • Milica Molitorisová,
  • Jana Dáňová,
  • Alexander M. Čelko,
  • Elena Nováková,
  • Mária Štefkovičová,
  • Zuzana Krištúfková,
  • Jana Malinová,
  • Ivana Králová Lesná

DOI
https://doi.org/10.3390/vaccines7040139
Journal volume & issue
Vol. 7, no. 4
p. 139

Abstract

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We assessed the long-term persistence of humoral immunity against diphtheria in adults with childhood vaccination and the immunogenicity of a booster dose considering demographic, behavioural and vaccinating factors. We conducted a trial in 200 healthy Slovak adults aged 24−65 years, immunised against diphtheria in childhood and against tetanus at regular 10−15 year intervals, and receiving a dose of a tetanus-diphtheria toxoid vaccine. The response was determined by ELISA antibody concentrations of paired sera before and at 4 weeks post-vaccination. A seroprotection rate of 21% (95% confidence interval, CI 15.6−27.3%) was found in adults up to 59 years since the last vaccination with seroprotective levels of antibodies against diphtheria ≥0.1 IU/mL and a geometric mean concentration of 0.05 IU/mL. Conversely, seropositive levels ≥0.01 IU/mL were observed in 98% of adults (95% CI 95−99.5%). Booster-induced seroprotection was achieved in 78% of adults (95% CI 71.6−83.5%) clearly depending on pre-booster antibody levels correlating with age and time since the last vaccination. Moreover, only 54.2% of smokers and 53.3% of patients on statins exhibited seroprotection. Booster vaccination against diphtheria was unable to confer seroprotection in all recipients of only childhood vaccination.

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