COVID-19 Vaccines over Three Years after the Outbreak of the COVID-19 Epidemic.

The outbreak of COVID-19 started in December 2019 and spread rapidly all over the world. It became clear that the development of an effective vaccine was the only way to stop the pandemic. It was the first time in the history of infectious diseases that the process of the development of a new vaccine was conducted on such a large scale and accelerated so rapidly. At the end of 2020, the first COVID-19 vaccines were approved for marketing. At the end of March 2023, over three years after the outbreak of the COVID-19 pandemic, 199 vaccines were in pre-clinical development and 183 in clinical development. The candidate vaccines in the clinical phase are based on the following platforms: protein subunit, DNA, RNA, non-replication viral vector, replicating viral vector, inactivated virus, virus-like particles, live attenuated virus, replicating viral vector combined with an antigen-presenting cell, non-replication viral vector combined with an antigen-presenting cell, and bacterial antigen-spore expression vector. Some of the new vaccine platforms have been approved for the first time for human application. This review presents COVID-19 vaccines currently available in the world, procedures for assurance of the quality and safety of the vaccines, the vaccinated population, as well as future perspectives for the new vaccine platforms in drug and therapy development for infectious and non-infectious diseases.

Application of loop-mediated isothermal amplification combined with colorimetric and lateral flow dipstick visualization as the potential point-of-care testing for Corynebacterium diphtheriae.

BACKGROUND: Diphtheria outbreaks occurred in endemic areas and imported and indigenous cases are reported in UE/EEA. Because of the high infectiveness and severity of the disease, early and accurate diagnosis of each suspected case is essential for the treatment and management of the case and close contacts. The aim of the study was to establish simple and rapid testing methods based on Loop-Mediated Isothermal Amplification (LAMP) assay for the detection of Corynebacterium diphtheriae and differentiation between toxigenic and non-toxigenic strains. METHODS: Corynebacterium diphtheriae and Corynebacterium ulcerans isolates from the National Institute of Public Health-National Institute of Hygiene collection were used for the development of LAMP assay for the diagnosis of diphtheria and nontoxigenic C. diphtheriae infections. Various colorimetric methods for visualization of results were investigated. Sensitivity and specificity of the assay were examined using a collection of DNA samples from various gram-positive and gram-negative bacteria. RESULTS: The LAMP assay for tox and dtxR genes was developed. The sensitivity and specificity of the assay were calculated as 100%. The detection limit was estimated as 1.42 pg/µl concentration of DNA template when the reaction was conducted for 60 min. However, the detection limit was lowered 10 times for every 10 min of reduction in the time of incubation during the reaction. Positive results were successfully detected colorimetrically using hydroxynaphthol blue, calcein, QuantiFluor, and lateral flow Milenia HybriDetect dipsticks. CONCLUSION: The assay developed in the study might be applied for point-of-care testing of diphtheria and other C. diphtheriae infections as well as for other infections caused by diphtheria-toxin producing Corynebacterium species. It is highly sensitive, specific, inexpensive, easy to use, and suitable for low-resource settings.

Changes in MLST profiles and biotypes of Corynebacterium diphtheriae isolates from the diphtheria outbreak period to the period of invasive infections caused by nontoxigenic strains in Poland (1950-2016).

BACKGROUND: Corynebacterium diphtheriae is a re-emerging pathogen in Europe causing invasive infections in vaccinated persons and classical diphtheria in unvaccinated persons. In the presented study we analysed genetic changes in C. diphtheriae isolates collected in Poland from the period before the introduction of the mass anti-diphtheria vaccination to the present time when over 98% of the population is vaccinated. METHODS: A total of 62 C. diphtheriae isolates collected in the 1950s-1960s, 1990s and 2000-2016 in Poland were investigated. Examined properties of the isolates included toxigenic status, presence of tox gene, biotype, MLST type (ST) and type of infection. RESULTS: A total of 12 sequence types (STs) were identified among the analysed C. diphtheriae isolates. The highest variability of STs was observed among isolates from diphtheria and asymptomatic carriers collected in the XX century. Over 95% of isolates collected from invasive and wound infections in 2004-2016 belonged to ST8. Isolates from the XX century represented all four biotypes: mitis, gravis, intermedius and belfanti, but the belfanti biotype appeared only after the epidemic in the 1990s. All except three isolates from the XXI century represented the biotype gravis. CONCLUSIONS: During a diphtheria epidemic period, non-epidemic clones of C. diphtheriae might also disseminate and persist in a particular area after the epidemic. An increase of the anti-diphtheria antibody level in the population causes not only the elimination of toxigenic strains from the population but may also influence the reduction of diversity of C. diphtheriae isolates. MLST types do not reflect the virulence of isolates. Each ST can be represented by various virulent variants representing various pathogenic capacities, for example toxigenic non-invasive, nontoxigenic invasive and nontoxigenic non-invasive.

[Susceptibility of Lactobacillus rhamnosus strains isolated from probiotic products to antimicrobial agents]. / Lekowrazliwosc szczepów Lactobacillus rhamnosus wyizolowanych z produktów probiotycznych.

INTRODUCTION: Probiotics Generally Recognized as Safe (GRAS), when given in relevant dose, are able to induce strain-specific beneficial effects for health of humans or animals. METHODS: L. rhamnosus strains originating from four medicinal products, 2 dietary foods for special medical purposes and dietary supplement, were tested for susceptibility to antibiotics and chemotherapeutics following L. rhamnosus and L.rhamnosus GG strain identity confirmation with use of PCR, rep-PCR and AFLP methods. RESULTS AND CONCLUSIONS: L. rhamnosus working seeds of medicinal products and isolates originating from dietary foods for special medical purposes or dietary supplement were found correctly classified on the levels of species or L. rhamnosus GG strain identities. Antibiotics and chemotherapeutics susceptibility profiles of L. rhamnosus strains allowed for choice of treatment options in six out of seven products under study.

Effect of different Bacillus Calmette-Guerin substrains on growth inhibition of T24 bladder cancer cells and cytokines secretion by BCG activated peripheral blood mononuclear cells of PBMCs.

BACKGROUND: Bladder carcinoma is the most common malignancy of the urinary tract. Approximately 75-85% of patients present non-muscle invasive bladder cancer (NMIBC). Standard primary treatment for NIMBC is transurethral resection (TUR) followed by intravesical Bacillus Calmette-Guerin (BCG) immunotherapy. BCG has been accepted as the most effective agent in clinical use against NMIBC. Various BCG substrains are used worldwide for bladder cancer immunotherapy although the impact of used BCG substrain on BCG antitumor capacity is a little investigated. OBJECTIVES: The aim of this study was to compare the antitumor capacity and the ability to trigger cytokines production of three BCG substrains by stimulation of the local innate immunity in vitro. MATERIAL AND METHODS: The human bladder cancer cell line T24 was co-cultured with each of the BCG substrains: Moreau, Tice and RIVM alone or with BCG pretreated DCs (dendric cells) and allogenic PBMCs derived from the same donor. The inhibition of T24 cell growth was evaluated by 3H-thymidine incorporation. Production of Th1 cytokines (IFN-γ, TNF-α, IL-12) and Th2 cytokines (IL-10, IL-4) was measured in cultures of BCG-activated PBMCs by ELISA test. RESULTS: An approximately two-fold inhibition of T24 cell proliferation was observed as a direct cytotoxic effect of tested BCG substrains on T24 cells. However, BCG inhibited the growth of tumor cells mainly by activating the effector cells of innate immunity. About a 10-fold inhibition of T24 cell proliferation was observed when T24 cells were co-cultured with allogenic BCG pretreated DCs and PBMCs derived from the same donor. The PBMCs activated by compared live BCG substrains secreted large amounts of TNF-α and IFN-γ cytokines. CONCLUSIONS: Tested BCG substrains had little direct inhibitory effect on T24 cell proliferation. Moreau evolutionarily early BCG substrain showed similar strong, indirect antitumor effects as evolutionarily late BCG substrains Tice and RIVM.

[Phenotypic and genotypic characterization of probiotic bacterial strains used in medicinal products]. / Fenotypowa i genotypowa charakterystyka probiotycznych szczepów bakteryjnych stosowanych w produktach leczniczych.

INTRODUCTION: The optimization of quality testing strategy of products containing probiotics might allow to general improvement of its safer use in humans. The goal of the study was the evaluation of quality expressed by identity, colony forming unit (CFU) and antibiotic sensitivity ofprobiotics used in medicinal products available in Poland using the appropriate and validated procedures. METHODS: The medicinal products containing L. rhamnosus, L. acidophilus, L. delbrueckii subsp. bulgaricus and B. animalis subsp. lactis, L. helveticus, and L. gasseri were tested for species identity performed with validated rep-PCR (BOXA 1R) method. The antimicrobial susceptibility of working seeds and strains isolated to 26 antibiotics were tested by disk diffusion and E-test methods using relevant references as recommended by EUCAST. The numbers of probiotic strains, expressed as cfu count per package, was done using plating plunge method. RESULTS: All strains tested, except B. lactis, were found to be resistant to trimethoprim-sulphamethoxazole, nalidixic acid, metronidazole, and colistin. B. lactis was resistant to aminoglycosides. L. rhamnosus strains were found to be resistant to vancomycin, (MIC > 256 microg/ml) similarly to ATCC strains (L. rhamnosus GG 53103 and 244). The sensitivity to other antibiotics was strain specific. The rep-PCR method was found species and strain specific. All products tested fulfilled declared countent as measured by cfu count/package. CONCLUSIONS: Quality of medicinal products containing probiotics was found undoubted and confirmed. The optimized strategy of quality monitoring of probiotics used in medicinal products can be used in dietary supplements and foodstuffs intended for particular nutritional uses.

Mechanism of Vipera berus venom activity and the principles of antivenom administration in treatment.

In the present paper, the actual knowledge on the composition and toxic properties of the European common viper venom was analyzed. The organism response to the particular components and the methods of neutralization of venom toxin in bitten person were presented. On the basis of literature data, the clinical course of envenomation with its classification according to the severity of symptoms was characterized. In the paper the situations in which administration of antivenom is required to neutralize toxic properties of venom and its possible adverse reactions were also described.

[Induction of micronuclei in somatic cells of mice exposed to x-rays or nonylphenol and to a combination of both agents]. / Indukcja mikrojader w komórkach somatycznych myszy eksponowanych na dzialanie promieniowania x lub nonylfenolu oraz na skojarzone dzialanie obu czynników.

The effects of X-rays, nonylphenol (NL) and combination of both agents on the induction of micronuclei in mouse somatic cells were investigated. Pzh: SFIS mice were exposed during 2 weeks, 5 days per week to X-rays (doses: 0.05 Gy, 0.10 Gy,0.20 Gy), nonylphenol (doses: 25 mg/kg bw NL, 50 mg/kg bw NL, 100 mg/kg bw NL) and to a combination of X-rays and nonylphenol (doses: 0.05 Gy + 25 mg/kg bw NL, 0.10 Gy + 50 mg/kg bw NL). Samples from peripheral blood were taken 1 week after the start of exposure and 24 h after the end of exposure, whereas samples from bone marrow were taken 24 h after the end of exposure. Results obtained show that ionizing radiation, nonylphenol and combination of X-rays-NL in low doses induced micronuclei in peripheral blood and bone marrow reticulocytes. In contrast combined exposure to higher doses of both agents caused reduction frequency of micronuclei in the comparison to effects of X-rays acting alone. In bone marrow polychromatic erythrocytes the induction of micronuclei was enhanced after combined exposure to both agents in lower and higher doses.

Reproductive effects after exposure of male mice to vincristine and to a combination of X-rays and vincristine.

This study was performed to investigate the effects of exposure to vincristine (VCR) alone (1 mg kg(-1) or 2 mg kg(-1)) and in combination with X-rays (0.25 Gy + 1 mg kg(-1) VCR or 1.00 Gy + 2 mg kg(-1) VCR) on the quality and quantity of spermatozoa, and the offspring of exposed Pzh : Sfis male mice. Both VCR and X-rays plus VCR reduced testis weight and sperm count, caused deterioration with respect to sperm morphology, and caused a slight increase in DNA damage. Exposure of some stages of male germ cells to high doses of VCR either alone or in combination with X-rays reduced the rate of pregnant females and the fertility of males. Such treatments reduced the number of total and live implantations, and induced dominant lethal mutations. The results of this study demonstrated the reproductive genotoxicity of VCR with or without X-rays, but did not unequivocally confirm their ability to cause external malformations in offspring.

Male-mediated developmental toxicity in mice after 8 weeks'exposure to low doses of X-rays.

PURPOSE: The aim of the study was to investigate the effects of subchronic irradiation of male mice on reproduction ability and induction of male-mediated teratogenesis. MATERIALS AND METHODS: Male mice were irradiated to 0.05 Gy, 0.10 Gy and 0.20 Gy daily for 8 weeks, 5 days per week. The total doses were 2.00 Gy, 4.00 Gy and 8.00 Gy, respectively. After the end of exposure each male was caged with two untreated females. The females were sacrificed on day 17 based on the finding of a vaginal plug. Females were examined for the number of live and dead implantations and the incidence of congenital malformations of survival foetuses. RESULTS: The fertilization ability of males was not diminished. The exposure to 0.20 Gy daily significantly decreased the percent of pregnant females and the number of total implantations. Exposure to 0.10 Gy and 0.20 Gy daily caused decreases in the number of live foetuses and induced dominant lethal mutations (over 50% at the highest dose). Exposure to each dose significantly enhanced the number of deaths (especially early) implants. The incidence of gross and skeletal malformations was not statistically significant, except for skeletal malformations at the highest dose. CONCLUSIONS: Results confirmed that irradiation of male germ cells cause genetic effects which could be transmitted to the offspring. After subchronic exposure to low doses the majority of mutations caused premature death. Subchronic exposure to low doses of X-rays did not induce external and skeletal malformations of surviving foetuses.