Does vaccination ensure protection? Assessing diphtheria and tetanus antibody levels in a population of healthy children

Abstract

Vaccination effectiveness is proven when the disease does not develop after a patient is exposed to the pathogen. In the case of rare diseases, vaccination effectiveness is assessed by monitoring specific antibody levels in the population. Such recurrent analyses allow the evaluation of vaccination programs. The primary schedule of diphtheria and tetanus vaccinations is similar in various countries, with differences mainly in the number and timing of booster doses. The aim of the study was to assess diphtheria and tetanus antibody concentrations in a population of healthy children.Diphtheria and tetanus antibody levels were analyzed in a group of 324 children aged 18 to 180 months. All children were vaccinated in accordance with the Polish vaccination schedule.Specific antibody concentrations greater than 0.1 IU/mL were considered protective against tetanus or diphtheria. Levels above 1.0 were considered to ensure long-term protection.Protective levels of diphtheria antibodies were found in 229 patients (70.46%), and of tetanus in 306 patients (94.15%). Statistically significant differences were found in tetanus antibody levels in different age groups. Mean concentrations and the percentage of children with high tetanus antibody titers increased with age. No similar correlation was found for diphtheria antibodies. High diphtheria antibody levels co-occurred in 72% of the children with high tetanus antibody levels; 95% of the children with low tetanus antibody levels had low levels of diphtheria antibodies.The percentage of children with protective diphtheria antibody levels is lower than that in the case of tetanus antibodies, both in Poland and abroad, but the high proportion of children without diphtheria protection in Poland is an exception. This is all the more puzzling when taking into account that Polish children are administered a total of 5 doses containing a high concentration of diphtheria toxoid, at intervals shorter than 5 years. The decrease in antibody titers occurring over time is a significant factor in vaccination program planning.Tetanus antibody concentrations were found to be high, but responses to the diphtheria and tetanus components were divergent. The percentage of children protected against diphtheria was significantly lower than protected against tetanus.

Protection against Haemophilus influenzae Type B, Diphtheria, and Tetanus in Children from Major Cities of Pakistan: A Community-Based Study

“…34 A similar finding was reported recently from Poland where the seroprotection against diphtheria was only 29.32%. 23 Our findings were however contrary to those reported from Iran, United Arab Emirates, and Palestine where seroprotection rate against diphtheria was 99, 86, and 87%, respectively. 24,26,27 Since the early 1990s, there has been a gradual introduction of the HiB conjugate vaccine into more and more routine programs.…”

“…21,22 A recent report from Poland regarding the immunization status against tetanus in vaccinated children (number ¼ 324; aged 18-180 months) showed that 29% of children were protected, 5.86% were unprotected, and 65.12% were considered as an intermediate. 23 A study from United Arab Emirates regarding the tetanus vaccine efficacy in a group of 227 children showed that 89.9% of children were protected, 4% showed lack of protection, and 2.2% were equivocal against tetanus. 24 From Gaza, Al Aswad reported that the protection of tetanus from the vaccine was 95% out of 180 children.…”

Risk factors for diphtheria outbreak in children aged 1-10 years in East Kalimantan Province, Indonesia

“…Previously, Gowin et al . 21 proved that even though tetanus and diphtheria antibody concentrations are quite high in children that have been immunized, the percentage of children protected against diphtheria is smaller than those against tetanus. Likewise, the results of research by Phadke et al .…”

Post Vaccination Titers of Serum Anti-Diphtheria in Indonesian Young and Middle-Aged Adults

“…Measurement were done using a standardized and calibrated instrument, and titers were expressed in IU/mL. Specific antibody titers greater than 0.1 IU/mL are considered protective against tetanus or diphtheria, levels above 1.0 IU/mL are considered a sign of long-term protection, while titer of 0.01 IU/mL is considered as partial protection [23].…”