Seroprevalence of diphtheria toxoid IgG antibodies in children, adolescents and adults in Poland

Abstract

BackgroundRecommendations for diphtheria immunization are to apply an effective primary immunization in infancy and to maintain immunity throughout life. Immunity against diphtheria depends primarily on antibody to the diphtheria toxin. This study evaluated the seroprevalence of IgG diphtheria antitoxin in sera of healthy children, adolescents and adults in Poland.MethodsA total of 1387 serum samples collected between 2010 and 2012 from individuals with ages ranging from 1 month to 85 years were investigated. Antibody concentrations were measured with an enzyme-linked immunosorbent assay (Anti-Diphtheria Toxoid ELISA IgG, Euroimmun, Germany).ResultsThe results showed that among 1387 individuals examined, 547 (39.4%) had anti-diphtheria toxoid IgG antibody levels below 0.1 IU/ml (36.9% ≤18 years and 40.5% >18 years old, respectively). The 212 (50.8%) children and 542 (55.9%) adults showed only basic protection (0.1-1.0 IU/ml) and need immediate booster. High levels of anti-diphtheria toxoid IgG antibodies (>1.0 IU/ml) were found more often in children and adolescent (12.2%) than in adults (3.6%) and this was statistically significant (P < 0.05). The proportion of seronegatives (< 0.1 IU/ml) in children below 2 years old, adolescents and young adults to 25 years old decreased from 53.5% to 17.4%. However, in older individuals the seronegative proportion tended to increase with age, from 22.7% in adults (26–30 years old) to 67.1% in subjects > 60 years old. Characteristically, in individuals > 40 years old high levels of anti-diphtheria toxoid IgG antibodies (>1.0 IU/ml) were not seen. There were no statistically significant differences in results in relation to gender.ConclusionsThe present study showed inadequate immunity levels to diphtheria amongst the Polish population, especially in adults > 40 years old and children ≤ 2 years old. To prevent reemergence of diphtheria an information campaign reminding people about recommendations concerning diphtheria booster vaccination in adults should be conducted. Moreover, the immunogenicity of the DTP vaccine used in Poland should be verified.

Seroprevalence and Determinants of Immunity to Diphtheria for Children Living in Two Districts of Contrasting Incidence During an Outbreak in East Java, Indonesia

“…Certainly, more recent diphtheria vaccination is a strong predictor of immunity in adults 7 and children, 21 where booster vaccines coincide with increasing antibody titre. 22 The combination of immunization (complete or partial) and natural challenge through exposure may also contribute to a quantitatively different level of response in areas where the reservoir of bacteria is relatively larger. We were unable to include in our analysis the time since immunization with specific vaccines, the inclusion of which would have helped to explore this further.…”

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

“…Similar results were obtained in other Polish studies, showing that up to 30% lacked the adequate protective level of diphtheria antibodies, even though a high percentage of children had undergone vaccinations in accordance with the official schedule. [11,12] …”

Immunity to Diphtheria and Tetanus in Army Personnel and Adult Civilians in Mashhad, Iran

“…Optical density was measured at 450/620 nm and antitoxin levels were determined by standard curves. According to manufacturer-recommended thresholds and the work of previous studies (13,17,21), the results were classified into 3 groups. The diphtheria groups were as follows: susceptibility (antitoxin level ＜0.1 IU/ mL), full protection (antitoxin level ＞1 IU/mL), and basic protection (antitoxin level ＞0.1 IU/mL and ＜1 IU/mL).…”

“…Prior studies have reported on diphtheria and tetanus immunity status in different populations (9)(10)(11)(12)(13). Some have studied special age groups (children, adults, or the elderly) (14)(15)(16) or special occupation groups (health care workers or military personnel) (17)(18)(19).…”