THE POTENTIAL USE OF ANTIBODIES FROM EGG YOLKS OF BIRD EGGS IN THE CONTEXT OF FOOD SECURITY OF THE RUSSIAN FEDERATION

Bering E. proposed the principle of passive immunization at the end of the 19th century. Today, it is still used to treat tetanus, diphtheria, botulism, rabies and poisonous animal bites (snakes, spiders and scorpions). As before, equine antibodies or their fragments are used as an antidote. But the unique properties of antibodies from the yolks of chicken eggs (IgY) make it possible to use them for a wide range of therapeutic and prophylactic purposes. IgY-antibodies are used in several countries (Canada, Germany, Japan, China) on an industrial scale to produce medical and veterinary drugs to protect humans and animals against pathogens, providing highly effective immunological protection. The Romanian Romvac Company SA is a separate company in the series of manufacturers of these drugs. This company produces IgY preparations in limited batches against many antigens and practices the production of personalized antibodies directed at pathogens of a particular patient. This approach is guaranteed to damage the pathogen, however unique it may be. The authors have analyzed many review articles on the use of IgY-technology. These antibodies are nonaddictive, non-toxic, do not interact with rheumatoid factor, complement, or Fc-fragments of immunocompetent cells, and do not cause antibody-dependent reinforcement of infection. Oral administration of specific IgY-antibodies significantly reduces the manifestations of celiac disease and pathological conditions caused by activation of pathogens in the gastrointestinal tract. Passive immunization of young farm animals with IgY-antibodies is economical and practical against many mammals, birds and aquatic animals. The great potential of this new direction can provide a rapid and cost-effective breakthrough in improving the adequate food security of the Russian Federation.

Tuberculosis, BCG Vaccination and COVID-19: Are They Connected?

Evidence from multiple scientific studies suggests that the Bacillus Calmette–Guérin (BCG) vaccine, widely used worldwide as a preventive measure against tuberculosis, also offers cross-protection against other pathogens. This review aimed to gather data from research that studied the mechanisms involved in the immunological protection induced by the BCG vaccine, which may be important in the control of viral infections, such as COVID-19. Through a literature review, we compiled information about the different BCG strains used worldwide, as well as the responses and protection elicited by them. We commented on the mechanisms of immune response to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and we discussed the possibility of cross-protection of different BCG strains on the control of COVID-19. Due to the immunomodulatory properties of BCG, some BCG strains were able to induce an effective cellular immune response and, through epigenetic modifications, activate cells of the innate immune system, such as monocytes, macrophages and natural killer cells, which are crucial for the control of viral infections. Although several vaccines have already been developed and used in an attempt to control the COVID-19 pandemic, some BCG vaccine strains may help stimulate the basal defences against these pathogens and can be used as additional defences in this and future pandemics.

Determination of diphtheria risk indicators based on the study of antidiphtheria immunity in the population of Dnipropetrovsk region

Background. Vaccination is the most effective part of primary prevention. Serological monitoring of infectious diseases covered by national immunization programs is very important as it provides up-to-date information on the burden of the infection and the immunological status of the population. The study was aimed to present an analysis of epidemiological monitoring of the protection against diphtheria of the population, to show the generalized epidemiological situation regarding diphtheria, and to determine the risk of diphtheria among the population of Dnipropetrovsk region. Materials and methods. Epidemiological analysis of diphtheria immunity (2017–2019) was performed based on the results of enzyme-linked immunosorbent assay of IgG antibodies levels against diphtheria toxin in 271 residents of Dnipropetrovsk region. Results. Analysis of the results revealed that only 30.6 % (n = 83) of the population have levels of antitoxic antibodies of 1.0 IU/ml or more, which provides sufficient protection against diphtheria in the next 5–7 years of life. At that time, the majority of the population (69.4 %) needs immediate one-time booster vaccination (n = 134; 49.5 %) or immediate basic vaccination (n = 54; 19.9 %) due to low levels of antitoxic diphtheria antibodies. In the age group 8–15 years, 65.9 % (n = 62) of patients require immediate basic or booster vaccination, which indicates that children of this age do not have basic immunological protection due to violations of the vaccination schedule or its absence. In the group aged 27 years and older, 79.1 % (n = 72) of the subjects do not have protective levels of anti-diphtheria antibodies, which indicates a lack of actual protection against diphtheria. Conclusions. The results indicate insufficient protection of the population against diphtheria. In this regard, the development of strategic measures for mass immunoprophylaxis of diphtheria both in children and adults is relevant. The country should conduct regular epidemiological monitoring, which would study the population’s immunity against diphtheria and other controlled infections, and draw up a long-term strategic and tactical plan to address shortcomings in the work of mass immunoprophylaxis of the population.

Investigation of the interaction of keratinocytes and Candida species

Our skin provides immunological protection against several pathogens. Skin epithelial cells respond to microbial stimuli in various ways, such as through the production of antimicrobial peptides or secretion of cytokines, although phagocytosis of potentially evading microbes was also reported. Relatively little is known about how skin keratinocytes differentiate between the presence of pathogenic and commensal fungi. In this project, we aimed to investigate how human keratinocytes interact with different Candida species, as common colonizers of the skin. While C. albicans is a common cause of cutaneous candidiasis, C. parapsilosisis rarely associated with this disease.For the experimentshuman skin keratinocyte cell lines (HaCaT, HPV-KER)were applied andchallengedwith C. albicans (SC5314 and WO1 strains) and C. parapsilosis (GA1 and CLIB214 strains)strains.We aimedto determine the extent to which C. albicans and C. parapsilosis damage human keratinocytes, their attachment to host cells, the keratinocytes’ ability to internalize these fungi and to examinecytokine production in response to stimuli. Our results suggest that C. albicans causes significantly more damage to human keratinocytes than C. parapsilosis and the HPV-KER cell line was more susceptibleto the infection. In both HaCaT and HPV-KER cells, the production of IL-6, IL-8, and CCL5 increased primarilyafter C. albicans infection. Based on the adhesion studies, there was a low degree of association in case of C. parapsilosis GA1 and CLIB214 compared to C. albicans SC5314 and WO1.

COVID-19: pathogen characteristics, natural and adaptive immune response mechanisms, genetic diversity and distribution

COVID-19 is a pandemic disease caused by a member of the Coronaviridae family, a beta-2 coronavirus named SARS-CoV-2. The COVID-19 pandemic lasting about 19 months has caused serious damage to the health of people on our planet – by the 13 of July 2021, more than 187.9 000 000 patients have been diagnosed and more than 4.0 mln patients died from infection (> 2.0 %). Scientists around the world are actively investigating the critically important molecular-genetic aspects of the biology of the pathogen (genome RNA structure, proteins properties) that are important for understanding the disease mechanisms, as well as the mechanisms of individual and collective immunological protection and vaccines development with non-specific prophylactics.

Efficiency of human plague vaccination in tuvinian natural plague focus. Message 2: dynamics of immune status indicators after revaccination

Relevance. In Russia, the live plague vaccine (LPV) is used for specific prophylaxis of plague. Immunological monitoring of humans vaccinated by LPV in order to search for informative diagnostic markers, as well as to improve the tactics of epidemiological surveillance of plague enzootic territories is an urgent area of research.The aim is to assess the parameters of cellular and humoral immunity in humans revaccinated by LPV who permanently reside on territory of the Tuvinian natural plague focus.Materials and methods. The study involved 76 volunteers from the Republic of Tuva, revaccinated by LPV. Blood sampling was performed before vaccination and 1, 3, and 6 months after revaccination. The study included the determination of cytokine production (IFN-γ, IL-4, TNF-α), specific antibodies, immunoglobulins (IgM, IgG, IgA and IgE) and lymphocyte subpopulation composition (CD3, CD4, CD8, CD16, CD19, immunoregulatory index).Results. A decrease in IgG and IgM and an increase in IgA were found after vaccination with LPV and their increase after revaccination. Correlation relationships were revealed between immunoglobulins, B cells and IL-4. Revaccination leads to an increase seroconversion. The activation of humoral immunity in humans vaccinated against plague is also evidenced by dynamics of changes in the subpopulation composition: an increase in B-lymphocytes and natural killer cells, a decrease in T-helpers and immunoregulatory index, and cellular immunity stimulation is an increase in spontaneous and induced production of pro- and anti-inflammatory cytokines.Conclusion. It has been shown that LPV is capable of causing the body’s immune restructuring and activating the cellular and humoral mechanisms of immunological protection. For a complete understanding of the development and preservation of antiplague immunity, it is necessary to continue the annual immunological monitoring of the population living on the territory of the Tuvinian natural plague focus, using additional modern research methods.

COVID-19 mRNA vaccine and antibody response in lactating women: a prospective cohort study

Background Immunological protection via breastfeeding is well known. The immunological profile of human milk changes during lactation. No clinical trials have been conducted in lactating women with the newest mRNA vaccines against SARS- CoV-2. A Few studies have shown the presence of antibodies in breastmilk after vaccination. The aim of this work is to study possible antibodies transfer via breastmilk and also the immunological characteristics of lactating women compared to non-lactating women, after using the BNT162b2 Pfizer vaccine. Methods This is a prospective cohort study with a convenience homogenous sample of 24 healthcare workers (14 lactating and 10 non-lactating women) enrolled at the time of COVID-19 vaccination. Clinical data was registered in a questionnaire. Titers of SARS-CoV-2 spike IgG, IgA and IgM were quantified in post vaccination blood and human milk. Antibody quantification was performed by an in-house ELISA to SARS-CoV-2 trimeric spike protein. Results All women showed immunity after vaccination with positive antibodies for IgM, IgA and IgG antibodies. The dominant serum antibody response was IgG. Modest levels of antibodies in breastmilk of lactating mothers were observed in this study, especially IgG in 42.9%. There was a moderate association between higher titers of IgG and a longer duration of breastfeeding (R= 0.55, p=0.041). Conclusions Evidence of antibody transfer in human milk after COVID-19 vaccination is scarce. The presence of antibodies in human milk is reported, but immunization through breastfeeding is still to be established.

Molecular Characterization of a Natural Mutant of Feline Calicivirus in China

During epidemiological surveillance of Feline calicivirus (FCV) isolates in Shanghai, China, a natural mutant of FCV, designated SH1909, was successfully isolated from a stray cat. The complete genome sequence of SH1909 was determined in this study. Sequence comparison and analysis showed that thirteen unique aa residues substitutions and single-aa insertion of N or Y were observed in SH1909, which indicated that SH1909 was a novel and natural mutant of FCV. Interestingly, phylogenetic analysis based on LC-VP1 showed SH1909 could be clustered into an independent evolutionary branch with some Chinese isolates and was more distantly related to vaccine strains, indicating its potential to escape from vaccine-elicited immunity. According to the predicted B-cell epitopes of LC-VP1, amino acid mutation sites and positive selective sites, peptide C (aa sites: 445–460) and, peptide D (aa sites: 425–440) located in the hypervariable regions of LC-VP1, may result in the decreased immunological protection. Moreover, amino acid sites 439 and 449 may be responsible for the potential immune escape of SH1909. This study provides an important insight into genetic variations of FCV and vaccine development.

Persistence of Anti-S Titre among Healthcare Workers Vaccinated with BNT162b2 mRNA COVID-19

The COVID-19 pandemic has led to health, social and economic consequences for public health systems. As a result, the development of safe and effective vaccines, in order to contain the infection quickly became a priority. The first vaccine approved by the Italian Agency for Drugs Authorization (AIFA) was the BNT162b2 mRNA vaccine, developed by BioNTech and Pfizer (Comirnaty). Comirnaty contains a molecule called messenger RNA (mRNA), which is a nucleoside-modified RNA that encodes the SARS-CoV-2 spike glycoprotein. Even if data from phase I suggest that vaccine induced antibodies can persist for up to six months following the second shot of BNT vaccine, data regarding the real duration of immunological protection are lacking. In this study, we aimed to evaluate the duration of serological protection by detecting the presence of anti-S-RBD (receptor-binding domain) antibodies for SARS-CoV-2 among a large group of healthcare workers (HCWs) three months after vaccination. 99% of HCWs had a detectable titre of anti-S SARS-CoV-2 antibodies 90 days after the second vaccine shot. Elderly operators showed significantly lower levels of protective antibodies when compared to the younger ones, thus they could become unprotected earlier than other operators.