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Lubimova et al. | Journal of Clinical and Translational Research 2023; 9(6): 392-397 393
have protective levels of post-vaccination antibodies [7]. It is 2. Methods
known that younger children (≤4 years) with juvenile idiopathic
arthritis (JIA) and patients with higher disease activity have an In the cross-sectional study, we included information about
increased incidence of infection [8,9]. The majority of vaccinations patients, who continued (n = 25) or declined (n = 51) vaccination
against vaccine-controlled infections occur at the age of 4 years. against diphtheria due to the onset of JIA. Study inclusion lasted
Immune-mediated disease and immunosuppressive treatment from 2019 to 2020 years and was conducted in the Department
(corticosteroids, tumor necrosis factor-alpha (TNF-α) inhibitors, of Pediatric Rheumatology of Saint-Petersburg State Pediatric
and anti-B cell therapy) may influence the protective level of anti- Medical University.
vaccine antibodies, and memory B-cell function [10-12]. Many Inclusion criteria were as follows: (i) Diagnosis of JIA was
national and international professional associations are calling established according to International League of Associations for
for the commitment of physicians and patients to the vaccination Rheumatology criteria [21]; (ii) age <18 years; (iii) done initial
st
process [10]. However, despite this, many patients, parents, and vaccination against diphtheria in the 1 year of life; and (iv) similar
physicians are opposed to vaccinations due to fear of flare of the demographic characteristics of the patients with a similar number
disease or low efficacy of the vaccination [9,13,14]. In the Russian of vaccines before the onset of the JIA.
Federation, the vaccination coverage of children with JIA in the Exclusion criteria were as follows: (i) Incomplete initial
st
last decade against major vaccine-controlled infections remains at vaccination in the 1 year of life and (ii) patients, whose
a low level and amounts to 50 – 58% [9]. demographic characteristics and number of vaccines differed
In recent years, the number of cases of diphtheria reported between groups.
worldwide has been gradually increasing. In 2018, 16,651 cases We evaluated demography, JIA category, treatment, vaccination
were registered, which is more than twice the annual average for status, and levels of antibodies against the diphtheria vaccine.
1996 – 2017 (8105 cases) [15]. The coronavirus disease 2019 The data about the JIA course and treatment were obtained from
pandemic caused the largest decline in vaccination in the past the patient’s charts. We selected the oligoarticular course (<5 active
three decades [16,17]. In 2021, according to the World Health joints), polyarticular course (extended oligoarthritis, rheumatoid
Organization, 25 million children did not receive a vaccine against factor [RF]-positive, and RF-negative polyarthritis), and systemic
measles, diphtheria, and tetanus [18]. It is known that diphtheria arthritis. The following classes of immunosuppressive medications,
is a life-threatening disease, with high mortality associated which were used by the patients during study recruitment, were
with asphyxia due to obstruction of the respiratory tract by taken into account: corticosteroids, methotrexate, and biologics.
edema and patches, as well as myocardial and nervous system 2.1. National vaccine schedule
involvement resulting from exposure to bacterial toxins [19]. In
the early stages, anti-diphtheria serum and antibacterial therapy Russian national vaccine schedule supposes diphtheria-
are used for treatment, which may eventually become ineffective tetanus-pertussis vaccination in 3, 4½, 6, and 18 months and
due to the development of resistance of C. diphtheriae to further diphtheria-tetanus vaccination in 6 – 7 and 14 years.
antibiotics [15]. The schedule of primary vaccinations against Vaccination is mandatory in the Russian Federation. According
diphtheria and tetanus is the same in different countries, with to national recommendations, immunosuppressive drugs were not
differences mainly in the number and timing of booster doses [20]. discontinued before/during diphtheria vaccination.
In the Russian Federation, vaccination against diphtheria is carried 2.2. Assessment of the levels of antibodies against diphtheria
out from the age of 3 months. The primary vaccination consists
of three doses, starting from 3 months, performed at intervals In all patients, the levels of post-vaccination antibodies
of 45 days. Revaccination is carried out 1 year after the initial (immunoglobulin G [IgG]) for diphtheria were measured with
vaccination, then at 7 and 14 years, for adults – every 10 years enzyme-linked immunosorbent assay during study inclusion.
throughout life [21]. Vaccination with three doses of diphtheria IgG concentrations were determined from calibration curves
toxoid vaccine is highly (87%) effective against symptomatic constructed using Dynex Technologies Inc. Software (USA).
disease and reduces transmission by 60% [19]. The protective level of antibodies was established by the criteria
Despite the developed immunization schedules, the global specified in the manufacturer’s instructions for diphtheria –
suboptimal vaccination coverage is typical for many countries. It 0.09 IU/ml (7, 5%; 0.004 IU/ml). To detect diphtheria antibodies,
may lead to outbreaks of vaccine-controlled infections, including we used the commercial kit, created by IBL International GMBH
diphtheria, due to a lack of collective immunity. To reduce (Germany). Information about the scheduled vaccination against
morbidity, it is necessary to achieve high vaccination coverage diphtheria was obtained from the personal vaccine certificates.
and introduce recommended booster doses, and it is also important 2.3. Statistical analysis
to identify persons, who require routine assessment of the level
of anti-vaccine antibody over the safety of post-vaccination Statistical analysis was performed with the software
immunity. The study aimed to evaluate the characteristics of JIA STATISTICA, version 10.0 (StatSoft Inc., USA) and MedCalc
associated with the refusal of the following vaccinations against (MedCalc Software, Belgium). The sample size was not calculated,
diphtheria. the power was 0.409. All continuous variables were checked by the
DOI: http://dx.doi.org/10.18053/jctres.09.202306.23-00103