A new inactivated whole-virion QazCovid-in® vaccine against COVID-19 was developed from SARS-CoV-2 isolated in Kazakhstan, inactivated by formaldehyde, and adjuvanted with aluminium hydroxide. Phase 1 and 2 clinical trials aimed at assessing the vaccine's safety, immunogenicity, and the duration of immunity induced by the QazCovid-in® vaccine after one or two immunisations. From 23.09.2020 to 19.03.2021 we performed a randomised, single-blind, placebo-controlled phase 1 clinical trial and from 18.10.2020 to 17.04.2021 an open-label phase 2 clinical trials of the QazCovid-in® vaccine with a 6 months follow-up at a single centre in Almaty, the Republic of Kazakhstan. Eligible healthy adults aged 18 years and older with no history of laboratory-confirmed SARS-CoV-2 infection were randomly assigned to the treatment groups using a computerised randomisation scheme generator. In the phase 1 clinical trial, two doses of the vaccine (5 μg each) or placebo (0·9% NaCl) were administered intramuscularly to 44 subjects aged 18–50 years, 21 days apart. In the phase 2 trial, 200 healthy participants were randomised into four equal-sized groups according to the age (18–49 or ≥50 years) and either single (day 1) or double (day 1 and 21) vaccination protocol. The primary outcomes were safety and tolerability. The secondary outcome was immunogenicity. The cellular response was measured by a whole-blood cytokine release assay (phase 1 only). The trials were registered with ClinicalTrials.gov NCT04530357. The QazCovid-in® vaccine was safe and well-tolerated and induced predominantly mild adverse events; no serious or severe adverse events were recorded in both trials. In the phase 1 trial, the percentage of subjects with a fourfold increase of antibody titres (sero conversion) in MNA was 59% after one vaccine dose and amounted to 100% after two doses. Neutralizing antibody titres reached the geometric mean titre (GMT) of 100 after administration of two doses. A statistically significant increase in the levels of pro-inflammatory cytokines after vaccination indicated the Th1-biased response. On day 180, 40% of placebo-treated subjects demonstrated a statistically significant increase in the levels of antibodies measured by both ELISA and MNA, which suggests the infection with SARS-CoV-2. In the phase 2 trial, 100% of subjects aged 18–49 years seroconverted for SARS-CoV-2 on day 21 after the first dose, as indicated by MNA yielding the GMTs of 32 or 30 in the one- and two-dose groups, respectively. Amongst ≥50-year-old subjects, the number of sero conversions in the two- and one-dose groups on day 21 was 94% and 92% with the respective GMTs of 25 and 24. After the second dose, the sero conversion rate reached 100%; however, the GMT was significantly lower when compared with the corresponding value measured in subjects aged 18–49 years (83 vs 143). In both trials, specific antibodies were detected in MNA and ELISA on study day 180, but the titres dropped in comparison to day 42. The results of this study serve as the rationale for the phase 3 study. The QazCovid-in® vaccine is safe and well-tolerated and promotes pronounced humoral immunity which lasts for at least 6 months after double intramuscular immunisation.

Background: The study was aimed at comparative evaluation of seasonal influenza vaccine RIBSP versus commercial vaccine VAXIGRIP® for immunogenicity and safety in the course of clinical trial phase II on healthy volunteers aged 18–60 years. Methods: The trial involved 150 subjects in randomized 2:1 groups that received either RIBSP vaccine or comparator vaccine VAXIGRIP®. One dose (0.5 ml) of either vaccine contained 15 μg of hemagglutinin of each influenza virus strain recommended by WHO for the Northern hemisphere in 2016–2017 flu season. The observation period lasted 21 day. The trial was registered at ClinicalTrials.gov identifier NCT 03016143. Results: Assessment of immunogenic activity of the vaccine under study showed that in 21 day the portion of participants with 4-fold seroconversions was 87.0% to A/H1N1; 63.0% to A/H3N2 and 59.0% to B virus. Antibody titer increase factor in the group of subjects that received RIBSP vaccine was 23.3 for A/H1N1; 4.4 for A/H3N2 and 4.5 for B virus. The volunteers that received RIBSP vaccine demonstrated 95% seroprotection level against A/H1N1; 84% against A/H3N2 and 80% against B virus. RIBSP vaccine met the CHMP criteria of the Committee for Medicinal Products for Human Use (CPMP/BWP/214/96). In the course of evaluating the vaccine safety no serious undesirable effects were recorded. All changes of laboratory data were slight and single in most cases. All recorded local reactions have been light in character and these have been predicted reactions observed at vaccination against influenza. Conclusion: Comparison of the allantoic inactivated split vaccine obtained in vaccines RIBSP and VAXIGRIP®, showed similar immunogenic activity. Both vaccines were safe for the study participants.

Background: The study was aimed at comparative evaluation of seasonal influenza vaccine RIBSP versus commercial vaccine VAXIGRIP® for immunogenicity and safety in the course of clinical trial phase II on healthy subjects up to 60 years. Methods: The trial involved 150 subjects in randomized 2:1 groups that received either RIBSP vaccine or comparator vaccine VAXIGRIP®. One dose (0.5 ml) of either vaccine contained 15 µg of hemagglutinin of each influenza virus strain recommended by WHO for the Northern hemisphere in 2016–2017 flu season. The observation period lasted 21 days. The trial was registered at ClinicalTrials.gov identifier NCT 03016143. Results: Assessment of immunogenic activity of the vaccine under study showed that in 21 days the portion of participants with 4-fold seroconversions was 80.0% to А/H1N1; 65.0% to А/H3N2 and 64.0% to B virus. Antibody titer increase factor in the group of subjects that received RIBSP vaccine was 13.4 for А/H1N1; 5.2 for А/H3N2 and 5.2 for B virus. The subjects that received RIBSP vaccine demonstrated 88% seroprotection rate against А/H1N1; 75% against А/H3N2 and 61% against B virus. In the course of evaluating the vaccine safety, no serious adverse events were recorded. All changes of laboratory data were slight and single in most cases. All recorded local reactions have been light in character and these have been predicted reactions observed at vaccination against influenza. Conclusion: Comparison vaccines RIBSP and VAXIGRIP®, showed similar immunogenic activity. The RIBSP vaccine is safe and immunogenic for the elderly and conforms to international criteria in CPMP/BWP/214/96.

Lyme borreliosis (LB) is an infectious disease caused by spirochetes of the Borrelia burgdorferi sensu lato complex. Transmission occurs through the bites of hard ticks within the genus Ixodes. Cases of fever of unknown origin are recorded in southern Kazakhstan, however, the prevalence of LB in this area remains unstudied. Almaty oblast is recognized as an endemic area for LB. Ixodid tick vectors also inhabit Jambyl oblast, where antibodies to LB agent were previously detected among residents, while it is classified as non-endemic. Turkistan oblast is also considered non-endemic for LB. The purpose of this study was to investigate the seroprevalence of IgG antibodies to B. burgdorferi s.l. among apparently healthy residents of Almaty city (Almaty oblast), Taraz city (Jambyl oblast), and Shymkent city (Turkistan oblast). A total of 465 human serum samples were collected from March 2022 to September 2023. Using the ELISA method, we detected the presence of IgG antibodies to the LB agent in 5.4% of the entire study group (24/465, 95% CI: 3.3-7.6%), and specifically in 9.3% of residents of Almaty city (11/118, 95% CI: 4.7-16.1%, p=0.03), 4.5% – Taraz city (11/242, 95% CI: 2.3-8.0%) and 1.9% – Shymkent city (2/105, 95% CI: 0.2-6.7%). The results of the study confirm the seroprevalence of IgG antibodies to B. burgdorferi s.l. among the population of Almaty city and Jambyl oblast, and also reveal seropositive samples in residents of Turkistan oblast, suggesting possible infection during travel to endemic regions. It is important to continue LB surveillance in endemic and emerging regions, as well as to raise awareness of the infection among healthcare workers and the general public in non-endemic areas.

Background: The aim of the present study was to develop and optimize an experimental ELISA test system for the detection of IgG antibodies to Toxocara canis and subsequently apply it for the assessment of human and canine exposure in Uralsk, Kazakhstan, within a One Health framework. Methods: A native somatic antigen of T. canis was fractionated by gel filtration, and the working fraction was selected by SDS-PAGE and pilot ELISA. The optimized test system was used for the analysis of sera of 1000 adult volunteers. Antibody avidity was determined in IgG-positive human specimens, and human seropositivity was evaluated for associations with demographic and questionnaire-derived variables. Serum samples from 100 stray dogs were tested by ELISA and fecal samples by copromicroscopy. Agreement with the commercial DRG ELISA was tested with 50 positive and 50 negative human serum samples. Results: The antigen fraction of 18–22 kDa showed the best separation between positive and negative sera. IgG antibodies against T. canis were detected in 116/1000 volunteers (11.6%). Seropositivity was 17.0% in the 2025 sample and 6.2% in the 2026 sample (odds ratio 3.10; 95% confidence interval 2.01–4.77; p < 0.001). No significant associations were found with sex, age, residence, or questionnaire-derived variables. Among seropositive volunteers, 28.4% had low-avidity, 26.7% intermediate-avidity, 29.3% intermediate/high-avidity and 15.5% high-avidity IgG. Overall, 78/100 of the stray dogs were copropositive, and 93/100 were seropositive. All copropositive dogs were seropositive, and 15 additional seropositive dogs were copronegative. Agreement with the DRG ELISA was 97.0% (Cohen’s κ = 0.94). Conclusions: The experimental ELISA allowed the assessment of T. canis exposure of humans and dogs. Seropositivity in humans in Uralsk showed exposure. High seropositivity in dogs and frequent egg shedding showed a substantial canine reservoir and a potential for environmental contamination. These results support integrated surveillance and control within a One Health context.