Prevention Of Respiratory Infections Research Articles

Masks and respirators for prevention of respiratory infections: a state of the science review.

SUMMARYThis narrative review and meta-analysis summarizes a broad evidence base on the benefits-and also the practicalities, disbenefits, harms and personal, sociocultural and environmental impacts-of masks and masking. Our synthesis of evidence from over 100 published reviews and selected primary studies, including re-analyzing contested meta-analyses of key clinical trials, produced seven key findings. First, there is strong and consistent evidence for airborne transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other respiratory pathogens. Second, masks are, if correctly and consistently worn, effective in reducing transmission of respiratory diseases and show a dose-response effect. Third, respirators are significantly more effective than medical or cloth masks. Fourth, mask mandates are, overall, effective in reducing community transmission of respiratory pathogens. Fifth, masks are important sociocultural symbols; non-adherence to masking is sometimes linked to political and ideological beliefs and to widely circulated mis- or disinformation. Sixth, while there is much evidence that masks are not generally harmful to the general population, masking may be relatively contraindicated in individuals with certain medical conditions, who may require exemption. Furthermore, certain groups (notably D/deaf people) are disadvantaged when others are masked. Finally, there are risks to the environment from single-use masks and respirators. We propose an agenda for future research, including improved characterization of the situations in which masking should be recommended or mandated; attention to comfort and acceptability; generalized and disability-focused communication support in settings where masks are worn; and development and testing of novel materials and designs for improved filtration, breathability, and environmental impact.

On the Possibility of Using the Topical form of the Recombinant Interferon alpha-2b Drug in the Prevention of Acute Respiratory Viral Infections in Organized Groups

Relevance. Respiratory infections are an urgent problem for organized groups, including military ones, since the transmission of pathogens by airborne droplets and household contact routes, physical and psychological stress on adaptive mechanisms contribute to the development of the epidemic process. There is no doubt that vaccination makes a significant contribution to the prevention of respiratory infections, but the contingent remains vulnerable to other pathogens against which there are no vaccines. Therefore, the search for new methods of non-specific prevention is necessary in maintaining the health of persons permanently residing in collectives. Aim. Evaluation of the possibility of using the topical form of the recombinant interferon α-2b drug for the prevention of acute respiratory viral infections in organized groups. Materials and methods. The work was carried out according to the methodology of a multicenter (3 Centers) double-blind controlled trial involving 3,235 people aged 18 to 22 years, who were divided into three groups: 1 gy. - received a recombinant interferon α-2b (Grippferon) drug 3 drops in each nasal passage 2 times a day in for two weeks; 2 g. - saline solution intranasally according to the same scheme; 3 g. - the volunteers did not receive anything. The frequency of respiratory infections was studied. Results and discussion. Medical monitoring of the study participants, which was carried out for 2 months, showed that in the groups from the Center 1, the incidence of acute respiratory diseases for 2 months in the main group (gr. 1) was 2.3 times lower than in the control (gr. 2) and the comparison group (gr. 3). In the Center 2 The data corresponded to the dynamics of Center 1: the incidence values were 2.4-2.5 times lower in Group 1. In Center 3, the values were 2.0-2.1, respectively. The epidemic effect of intranasal administration of the topical form of the drug recombinant interferon α-2b is due to its effect on the factors of mucosal immunity, which contributes to non-specific protection and increased body resistance against respiratory infections. Conclusions. The presented advantages of the recombinant interferon α-2b drug make it possible to draw attention to the clinical feasibility of its use for preventive purposes in organized groups, including military ones, from the position of high epidemiological effectiveness, both pre-exposure and post-exposure prevention of acute respiratory viral infections.

Echinacea Reduces Antibiotics by Preventing Respiratory Infections: A Meta-Analysis (ERA-PRIMA).

Respiratory tract infections (RTIs) are the leading cause of antibiotic prescriptions, primarily due to the risk for secondary bacterial infections. In this study, we examined whether Echinacea could reduce the need for antibiotics by preventing RTIs and their complications, and subsequently investigated its safety profile. A comprehensive search of EMBASE, PubMed, Google Scholar, Cochrane DARE and clinicaltrials.gov identified 30 clinical trials (39 comparisons) studying Echinacea for the prevention or treatment of RTIs in 5652 subjects. Echinacea significantly reduced the monthly RTI occurrence, risk ratio (RR) 0.68 (95% CI 0.61-0.77) and number of patients with ≥1 RTI, RR = 0.75 [95% CI 0.69-0.81] corresponding to an odds ratio 0.53 [95% CI 0.42-0.67]. Echinacea reduced the risk of recurrent infections (RR = 0.60; 95% CI 0.46-0.80), RTI complications (RR = 0.44; 95% CI 0.36-0.54) and the need for antibiotic therapy (RR = 0.60; 95% CI 0.39-0.93), with total antibiotic therapy days reduced by 70% (IRR = 0.29; 95% CI 0.11-0.74). Alcoholic extracts from freshly harvested Echinacea purpurea were the strongest, with an 80% reduction of antibiotic treatment days, IRR 0.21 [95% CI 0.15-0.28]. An equal number of adverse events occurred with Echinacea and control treatment. Echinacea can safely prevent RTIs and associated complications, thereby decreasing the demand for antibiotics. Relevant differences exist between Echinacea preparations.

MV130 in the Prevention of Recurrent Respiratory Tract Infections: A Retrospective Real-World Study in Children and Adults.

Respiratory tract infections (RTIs) are among the most common and important problems in clinical medicine, making antibiotics the gold standard therapeutic option regardless of their frequent viral etiology. Their excessive and inappropriate use contributes to the rapid rise of antibiotic resistance and underscores the need for alternative strategies, especially when dealing with recurrent RTIs. Prevention is the ideal alternative, but specific vaccines targeting a wide range of respiratory pathogens are scarce. MV130 is a sublingual bacterial vaccine that induces trained immunity and provides non-specific protection against respiratory pathogens in various clinical settings according to the concept of TIbV (Trained Immunity-based Vaccine). A retrospective real-world study (RWS) was conducted to evaluate the annual incidence of RTIs and the consumption of antibiotics before and after the administration of MV130, using data sourced from the medical records of 599 patients (186 children and 413 adults) who suffered from recurrent RTIs. The median number of infectious episodes in children was significantly reduced by more than 70% from 5 episodes (interquartile range (IQR) 4.0-6.0) to 1 (IQR, 0.0-2.0) (p < 0.001) after MV130. Similarly, in adults, the median number of episodes before MV130 immunization was 5 (IQR, 4.0-6.0), which dropped by more than 80% to 1 (IQR, 0.0-1.0) during the year following MV130 immunization (p < 0.001). The median number of antibiotic courses also significantly decreased for both children and adults by over 80% (p < 0.001). This RWS showed that MV130 is an effective strategy for the prevention of respiratory infections and the reduction of associated antibiotic consumption.

Vitamin D Primary Prevention of Respiratory Infections and Asthma in Early Childhood: Evidence and Mechanisms

Respiratory infections are a leading cause of child morbidity worldwide and asthma is the most common chronic disorder in childhood. Both conditions associate with high socioeconomic costs and are major reasons for medication prescriptions and hospitalizations in children. Vitamin D deficiency has concomitantly increased with asthma prevalence and is hypothesized to play a key role in the development. Current evidence suggests that high prenatal and early childhood vitamin D could be protective against respiratory infections and asthma in some studies where several mechanisms are proposed. However, other studies have reported no effects on these outcomes. Therefore, future large intervention studies on this topic are warranted. Mechanistic studies have shown that vitamin D holds antimicrobial properties by inducing production of several peptides through altered gene expression. Others have shown a complex interplay between asthma risk genotypes, the sphingolipid pathway and prenatal vitamin D in early childhood asthma. Vitamin D has also been suggested to change both airway immune- and microbiota profiles, which are directly related to asthma risk. Finally, systemic low-grade inflammation seems to be regulated by vitamin D exposure. This review presents current literature of the primary preventive effect of vitamin D on early childhood asthma and respiratory infections. Mechanisms of actions are discussed and gaps in knowledge are highlighted to facilitate planning of future intervention trials.

Non-specific prevention of respiratory infections during vaccination against COVID-19

The novel coronavirus infection (COVID-19) has a suppressive effect on innate immunity, which is a prerequisite for developing strategies to enhance this non-specific link as a preventive measure to protect against other respiratory infections during the ongoing circulation of mutating strains of the SARS-CoV-2 virus. Despite the currently developed and available preventive measures, it has been noted that in persons who have undergone COVID-19, repeated episodes of both coronavirus infection and diseases caused by other pathogens have been recorded.&#x0D; This review analyzes data from the biomedical literature and considers examples of health risks associated with continued infection with pathogens that cause respiratory tract pathologies. It also reflects the ways and approaches of possible preventive measures, the purpose of which is to prevent the development of pathologies of both the respiratory organs and other systems.

Transpiring, phytoncidal and gas-absorbing properties of indoor plants and their role in improving the air quality in preschool environments

BACKGROUND: The high incidence of respiratory diseases among children attending preschool educational institutions highlights the need for prevention of respiratory tract infections. With children spending on average up to 10 hours a day in educational settings, the quality of the indoor air environment, including microbial contamination and low relative humidity, poses a risk for respiratory diseases. Placing a selection of plants in organized groups of children can offer a promising and cost-effective approach to promote health and well-being in the modern preschool education system. AIM: To select indoor plants based on their species and quantity to improve the air quality in organized children’s groups. Moreover, the paper presents recommendations for the installation and maintenance of the plants to create healthier environment for children. MATERIALS AND METHODS: Among more than 820 species of indoor plants, we have identified the most suitable options for preschool institutions. The selection process involved measuring the dimensions of the plants and the surface area of their leaves using a metric method. To assess the air quality, we conducted air sampling throughout the working week, once per hour, using an aspiration method with a sampling device PU-1B. Simultaneously, we measured the microclimate parameters in all the rooms included in the study. Furthermore, we studied the gas absorption capacity of indoor plants in controlled laboratory conditions within seed chambers with a volume of 200 liters. RESULTS: In rooms where plants were present, the levels of microorganisms varied. The average relative humidity values in all rooms were consistently below the hygienic standard of 40–60%, as outlined in SanPiN 1.2.3685-21, except for specific times. At 8:00, 9:00, 10:00, and 18:00, the relative humidity ranged from 15–35%. When exposed to a formaldehyde concentration of 3 times the maximum permissible concentration (MPC) Chlorophytum comosum reduced it to the regulated value of 0.01 MPC within 38 hours while the corresponding values for Sansevieria trifasciata and Cyperus alternifolius were 24 and 27 hours, respectively. CONCLUSION: Introducing a variety of indoor plants into a preschool educational setting can have significant benefits for air quality. The plants possess phytoncidal, transpiring, and gas-absorbing properties that contribute to a reduction in the overall number of microorganisms, a decrease in chemical pollutants, and an increase in air humidity. Our analysis showed that in the presence of indoor plants, the concentration of formaldehyde decreases to a regulated and safe level.

A multifactorial impact on respiratory morbidity in people of reproductive age and effectiveness of natopherine- and andropherine-containing odorants regarding a non-specific resistance of the nasal mucosa and lowered morbidity of respiratory infections

Prevention of respiratory infections during epidemic periods is an important task of modern health care in Russia and worldwide. One of such approach may rely on use of volatile substances capable of activating nonspecific resistance of the nasal mucosa. Long-term application of synthetic analogues of female pheromones to young males leads to lowered morbidity of respiratory diseases, increased levels of secretory immunoglobulins, as well as decrease peripheral blood of eosinophilia levels in subjects with allergic diseases. Based on this, the aim of the study was set to study an impact of anamnesis factors and indicators reflecting the functioning of nasal mucosal immunity, its nonspecific resistance, on emerging frequent respiratory morbidity; as well as to evaluate effectiveness of natopherine- and andropherine-containing odorants regarding dynamics of such indicators and to reduce incidence of respiratory infections in young subjects. Materials and methods. There were examined 46 apparently healthy boys and girls aged 18 to 22 years. The frequency of respiratory morbidity, anamnesis factors, and the results of non-invasive studies (cytokine concentrations in the nasopharyngeal aspirate and rhinocytograms). Within 30 days, all young subjects were applied to the nasolabial fold synthetic analogues of male (andropherine) and female (natopherine) pheromones (andropherine for young female, natopherine for young male). A re-examination with the above mentioned studies was carried out on day 14 and day 30 of the study. The incidence of respiratory infections was reassessed one year after the onset. Results. The study showed identified a number of predictors and protectors of frequent and long-term respiratory morbidity in young subjects. The predictors of this condition were presented by catamnestics markers of allergic anomalies of the constitution, behavioral factors (smoking), as well as immune indicators of allergy (IL-4) and mucociliary clearance deficiency. A monthly course of odorant applications on the skin of the nasolabial fold using synthetic analogues of male and female pheromones (steranes) has a positive effect both on the nonspecific resistance of the nasal mucosa as well as on the immune parameters. After a month of using steranes, the nasal mucosa is completely decontaminated from coccal microorganisms, and over the next 12 months, the frequency of respiratory infections decreases. This indicates about a prominent clinical effect of the odorants applied.

Incidence of Acute Respiratory Infections in Dental Care Professionals

Introduction: A wide spread of causative agents of acute respiratory infections and an intensive use of aerosol-generating procedures in dentistry affect the disease incidence in dental care professionals. This issue, however, remains poorly studied. Objective: To study the incidence of acute respiratory infections in dental health personnel in order to optimize appropriate preventive measures. Materials and methods: In 2021, we conducted a descriptive retrospective epidemiological study of the workplace absence due to acute respiratory diseases among 352 dental care professionals (case study group) and 782 people unrelated to the medical field (control group). To assess the statistical significance of differences in the incidence rates, the Pearson criterion (χ2) was applied. The data were analyzed in Microsoft Office Excel 2013 and Epi Info v. 1.4.3. Results: We established that the incidence rates of viral respiratory diseases in the dental health personnel were 2.2 times higher than in the control group (301.14 and 136.83 ‰, respectively; p = 0.00001). During the respiratory illness season, the cases were 3.3 times more likely to get sick (p = 0.000001). At the same time, the incidence in the cases working in therapeutic and orthopedic departments and applying aerosol-generating procedures was 2.7 times higher compared to those working in other departments (p = 0.00153). Females generally prevailed among therapists and orthopedists (83.81 %) and the rates of viral respiratory infections in them were found to be 2.73 times higher than in male surgeons (p = 0.00134). Conclusions: The high incidence of acute respiratory infections observed in the dental care professionals, especially in those using aerosol-generating procedures in their everyday practice, shows the necessity of improving measures for prevention of respiratory tract infections in dentistry.

Secretory IgA in patients with COVID-19 at different regimens of using multicomponent vaccine Immunovac-VP-4

The mucosal immunity performs an important function in prevention of respiratory infections including COVID-19. The search for approaches to activate the synthesis of post-infectious antibodies by correcting the factors of innate and adaptive immunity at mucous membranes of respiratory tract in patients with infection caused by the new coronavirus may be relevant for the treatment of patients with COVID-19. The aim of our study was to assess the concentrations of sIgA in the upper respiratory tract in patients with a confirmed diagnosis of Coronavirus infection caused by the COVID-19, and to evaluate the effect of an immunostimulating drug of bacterial origin upon the sIgA secretion.&#x0D; The patients were divided into two groups: group 1 (n = 45), received basic therapy; group 2 (n = 33), in addition to basic therapy, received the bacterial vaccine Immunovac-VP-4 according to a combined scheme. The biomaterial sampling was carried out by scraping of epithelial cells from the nasal mucosa, pharyngeal scraping and salivary gland secretion on days 1, 14 and 30 of the study. sIgA levels in all biological fluids were studied using ELISA technique (JSC Vector-Best, Russia).&#x0D; 14 days after the start of observation, the dynamics of sIgA levels in nasal scrapings in group 1showed a significant decrease relative to the baseline values (p = 0.02), whereas the level of sIgA remained unchanged during the specified period (p = 0.07) in the group of patients receiving, along with basic therapy, additional Immunovac-VP-4 treatment. The dynamics of sIgA level in pharyngeal scrapings in the group of patients receiving only basic therapy did not change throughout the study period. Menwhile, the group of patients receiving basic therapy supplemented with Immunovac-VP-4 showed a significant increase in sIgA levels by the 30th day of follow-up over the baseline values (p = 0.02). The level of sIgA in salivary gland secretions did not differ significantly between the study groups during the entire follow-up period.&#x0D; The results of our study showed that, in order to assess the state of mucosal immunity in patients with COVID-19, one may recommend determination of sIgA in nasal secretions. The Immunovac-VP-4 prescribed in complex therapy is accompanied by an increase in the sIgA levels at the mucous surfaces of the respiratory tract.

The Effects of Vitamin D Supplementation on Respiratory Infections in Children under 6 Years Old: A Systematic Review.

Childhood respiratory tract infections (RTIs) pose a significant health burden, especially in children under six years old. The main objective of this systematic review was to assess the effectiveness of vitamin D supplementation in the prevention of RTI in this population while also exploring potential effect modifiers such as age, baseline vitamin D status, and type of respiratory infection. A systematic review of the literature published up to February 2023 was conducted according to PRISMA guidelines, searching PubMed, Web of Science, Cochrane, and Scopus databases. Eight studies met the inclusion criteria, which investigated the association between vitamin D supplementation and respiratory infections in children between zero and five years old. The included studies were conducted between 2012 and 2021, encompassing a total of 2189 children from five randomized trials, two case-control studies, and one prospective cohort study. The relationship between vitamin D supplementation and the prevention of childhood RTI was not consistently observed across all included studies. Pooled results demonstrated varied effects of vitamin D supplementation on respiratory infection incidence, severity, and symptoms. Three studies reported statistically significant associations between low vitamin D levels and respiratory infections (OR = 4.90, OR = 6.97), while one study found that children who received vitamin D supplementation of 800 UI/day for 3 months during the cold season had fewer episodes of respiratory symptoms (RR = 0.55) and recovered more quickly from acute RTI. Lastly, according to one study, vitamin D intake < 80 IU/kg/day was significantly associated with the risk of acquiring pneumonia (OR 7.9) but not bronchiolitis. The remaining five studies found no statistically significant differences in infection rates or severity (p-value > 0.050). The available evidence on the effectiveness of vitamin D supplementation for preventing and treating respiratory infections in children under six years old is limited, with only a few favorable effects being reported. In some cases, a dose of 80 UI/kg/day was found to provide significant protection for acute respiratory infections, although in the major trials the only benefit was a quicker recovery and fewer respiratory symptoms, with no impact on incidence and severity of respiratory infections. Nevertheless, the study protocol, the supplementation dose, and duration of supplementation had significant variations between studies, leading to inconclusive findings.

Guidelines for the Management of Respiratory Infectious Diseases in Children in Japan 2022.

The members of the Japanese Society for Pediatric Infectious Diseases and the Japanese Society of Pediatric Pulmonology have developed Guidelines for the Management of Respiratory Infectious Diseases in Children with the objective of facilitating appropriate diagnosis, treatment and prevention of respiratory infections in children. The first edition was published in 2004 and the fifth edition was published in 2022. The Guideline 2022 consists of 2 parts, clinical questions and commentary, and includes general respiratory infections and specific infections in children with underlying diseases and severe infections. This executive summary outlines the clinical questions in the Guidelines 2022, with reference to the Japanese Medical Information Distribution Service Manual. All recommendations are supported by a systematic search for relevant evidence and are followed by the strength of the recommendation and the quality of the evidence statements.

Clinical efficacy and antioxidant properties of interferon inducers in the treatment of acute respiratory diseases in children

Introduction. Diagnosis, treatment and prevention of respiratory infections in the practice of a pediatrician occupy one of the leading places. Currently, much attention is paid to various links in the pathogenesis of viral respiratory diseases. Among them, particular importance is attached to the system of antioxidant defense and cytokine regulation of inflammation. It is important to study the effect of various drugs on these links of pathogenesis in order to increase the clinical effectiveness of therapeutic methods.Aim. To evaluate the clinical efficacy and impact on lipid peroxidation of Kagocel® in the treatment of respiratory viral infections in children.Materials and methods. An observational study was conducted involving 124 children aged 6 to 15 years with manifestations of a respiratory viral infection who received symptomatic treatment, of which 89 children additionally took antiviral therapy with Kagocel®.Results. Along with the good tolerance of Kagocel® and the absence of side effects in children on the background of its use, a significantly shorter period of regression of the main clinical symptoms of acute respiratory infection was shown. It was noted that in children taking Kagocel® on the 3rd-5th day of therapy, there is an increase in the total antioxidant activity of blood plasma and a decrease in the level of malondialdehyde compared with patients who did not take the drug, which demonstrates the antioxidant effects of Kagocel®, which certainly have a positive effect on the character course of the healing process.Conclusion. Kagocel® has been shown to have high clinical efficacy and antioxidant effects.

Association between handwashing and gargling education for children and prevention of respiratory tract infections: a longitudinal Japanese children population-based study.

A longitudinal study was conducted to examine the effects of handwashing and gargling education for children on the prevention of respiratory tract infections (RTIs) in children in Japan. The study included 38,554 children born in 2010 who were enrolled in a longitudinal study. Information on children's hygiene education regarding handwashing and gargling was collected in a survey at the age of 3.5years. Based on parents' reports of doctors' diagnoses, airway infections and influenza events in the 12-month duration before the survey were evaluated for RTIs at the ages of 4.5 and 9years. Poisson regression with robust variance was performed to examine the effects of hygiene education on RTIs prevention. The supplementary analysis was stratified by household income. Children were categorized into different groups: 38% in the handwashing and gargling group, 29% in the handwashing group, 0.1% in the gargling group, and 9.7% in the no-education group. Exclusions were made for non-respondent children (23%) and those in the gargling group. Hygiene education was associated with decreased influenza at the age of 4.5years in the handwashing (adjusted RR [aRR] = 0.8; 95% CI, 0.8-0.9) and handwashing and gargling groups (aRR = 0.8; 95% CI, 0.8-0.9) compared with no education. However, no preventive effects on airway infections at the age of 4.5 and 9, influenza at the age of 9, or hospitalization between the ages of 3.5 and 9years were detected. Handwashing and gargling could significantly prevent influenza in low-income households (aRR = 0.7; 95% CI, 0.6-0.8). Conclusions: Gargling education was widespread and mostly combined with handwashing education in Japan. Hygiene education significantly affected prevention of influenza infections at the age of 4.5years, especially in low-income households. •Previous intervention studies showed handwashing and gargling are effective in preventing respiratory tract infections. •We conducted a longitudinal study on handwashing and gargling education in Japanese children and found that handwashing and gargling were widely practiced together. •Handwashing and gargling education were related to a reduction in influenza, particularly in low-income households.

Knowledge, Attitude, and Self-reported Practices on Prevention of Respiratory Infections among Two Groups of Islamic Pilgrims, Thailand, 2021

Religious mass gatherings can foster contagious disease transmission in the home countries of pilgrims. Thailand has two major Muslim pilgrims: the Hajj and the Dawah. This study aimed to compare their knowledge (K), attitude (A), and self-reported practice (P), and qualitatively evaluate their perceptions regarding the prevention of respiratory infections. A cross-sectional mixed methods study was conducted. Multistage sampling was conducted in Hajj participants, while convenience sampling was used with the Dawah participants at two gathering places. Pearson’s chi-square test was used to compare KAP scores between the two groups. We conducted qualitative interviews with 13 purposively chosen participants. There were 111 Hajj and 228 Dawah participants. Most Hajj respondents were in the age group of ≥50 years, while most Dawah respondents were between 30–49 years. Overall, the Hajj group had a significantly higher proportion of good knowledge scores than the Dawah group, with 76.6 and 56.1, as well as the positive attitude score of 97.3 and 87.7. The Hajj group was more receptive to receive health education about respiratory infections before their pilgrimage. Preparatory education classes should be initiated for Dawah Muslims before they attend a foreign gathering event.

Changes in nasal, pharyngeal and salivary secretory IgA levels in patients with COVID-19 and the possibility of correction of their secretion using combined intranasal and oral administration of a pharmaceutical containing antigens of opportunistic microorganisms.

Although extensive research has been conducted on the role of local immunity in patients with SARS-CoV-2, little is known about the production and concentrations of secretory IgA (SIgA) in different mucosal compartments. This article aims to assess the secretion of SIgA in the nasal and pharyngeal compartments and saliva of patients with COVID-19 and to investigate the possibility and efficiency of correction of their secretion using combined intranasal and oral administration of a pharmaceutical containing antigens of opportunistic microorganisms. This study included 78 inpatients, aged between 18 and 60 years, who had confirmed COVID-19 with moderate lung involvement. The control group (n=45) received basic therapy, and the treatment group (n=33) was additionally administered the bacteria-based pharmaceutical Immunovac VP4 from day 1 to day 10 of hospitalization. SIgA levels were measured by ELISA at baseline and on days 14 and 30. No systemic or local reactions associated with Immunovac VP4 were reported. We observed a statistically significant reduction in the duration of fever and hospitalization in patients who received Immunovac VP4 compared with those from the control group (p=0.03 and p=0.05, respectively). Changes over time in SIgA levels in nasal swabs were found to be significantly different in the two treatment groups (F=7.9, p[78.0]<0.001). On day 14 of observation, patients in the control group showed a statistically significant reduction in SIgA levels from baseline (p=0.02), whereas patients in the Immunovac VP4 group had stable SIgA levels (p=0.07). On day 30 after the start of treatment, there was a statistically significant increase in SIgA levels in the Immunovac VP4 group compared with baseline (from 77.7 (40.5-98.7) μg/L to 113.4 (39.8-156.7) μg/L; p=0.05) and the levels measured on day 14 (from 60.2 (23.3-102.9) μg/L to 113.4 (39.8-156.7) μg/L; p=0.03). The control group showed a statistically significant decrease in levels of nasal SIgA (to 37.3) on day 30 (p=0.007 for comparison with baseline values and p=0.04 for comparison with levels measured on day 14). Changes over time in SIgA levels measured in pharyngeal swabs were also different between the two treatment groups, and this difference reached statistical significance (F=6.5, p[73.0]=0.003). In the control group, this parameter did not change throughout the study (p=0.17 for a comparison between the levels measured on day 14 and the baseline values, and p=0.12 for a comparison between the levels measured on day 30 and the baseline values). In the Immunovac VP4 group, there was a statistically significant increase from baseline in SIgA levels on study day 30: from 1.5 (0.2-16.5) μg/L to 29.8 (3.6-106.8) μg/L (p=0.02). Changes over time in salivary SIgA did not show a significant difference between study groups (F=0.3, p[66.3]=0.75). As part of combination therapy, the bacteria-based immunostimulant agent Immunovac VP4 increases SIgA levels in the nasal and pharyngeal compartments and induces clinical improvement. Induced mucosal immunity is central to the prevention of respiratory infections, particularly in patients with post-COVID-19 syndrome.

Quantitative assessment of structural changes in the cornea against the background of long-term wearing of contact lenses according to the results of confocal microscopy

Introduction. The article presents an objective assessment of the morphofunctional status of the cornea during the long-term wear of soft contact lenses (SCLs). Aim. To assess the qualitative and quantitative changes in the cornea microstructure using the laser confocal microscopy during the long-term wear of SCLs, as well as combined tear replacement therapy based on formulations consisting of trehalose and hyaluronic acid. Materials and methods. The study included 62 patients (124 eyes) divided into three groups. The first two groups included 32 patients (64 eyes) with different degrees of myopia, using SCLs as an optical correction for 7–15 years (11 years on average): Group 1 included 15 patients (30 eyes) using tear replacement therapy in the form of a drug containing trehalose and hyaluronic acid twice a day for 3 months, Group 2 included 17 patients (34 eyes) who did not receive any tear replacement therapy. The laser corneal confocal microscopy was performed using Heidelberg Retinal Tomograph III followed by digital image processing aided by author software with the focus on the state of nerve fibers and dendritiform macrophages (Langerhans cells). Results and discussion. The laser corneal confocal microscopy with assessment of the structure of the corneal nerve fibers and Langerhans cells can be used for the dynamic monitoring of the state of the anterior segment of the eye in SCL users. When pathological changes are detected, a patient may be recommended the corneotrophic therapy and (or) switching to another type of contact lenses. Conclusion. The use of tear replacement medications containing trehalose and hyaluronic acid improves the subjective tolerance of SCLs and also makes it possible to significantly reduce the severity of epitheliopathy in patients, who use SCLs as optical correction for a long time.

Characterization of viral pathogens associated with symptomatic upper respiratory tract infection in adults during a low COVID-19 transmission period.

The epidemiology of respiratory tract infections (RTI) has dramatically changed over the course of the COVID-19 pandemic. A major effort in the clinical management of RTI has been directed toward diagnosing COVID-19, while the causes of other, common community RTI often remain enigmatic. To shed light on the etiological causes of RTI during a low COVID-19 transmission period in 2021, we did a pilot study using molecular testing for virologic causes of upper RTI among adults with respiratory symptoms from Almaty, Kazakhstan. Adults presenting at two public hospitals with respiratory symptoms were screened using SARS-CoV-2 PCR on nasopharyngeal swabs. A subset of RTI+, COVID-19-negative adults (n = 50) was then tested for the presence of common RTI viruses and influenza A virus (IAV). Next generation virome sequencing was used to further characterize the PCR-detected RTI pathogens. Of 1,812 symptomatic adults, 21 (1.2%) tested SARS-CoV-2-positive. Within the COVID-19 negative outpatient subset, 33/50 subjects (66%) had a positive PCR result for a common community RTI virus, consisting of human parainfluenza virus 3-4 (hPIV 3-4) in 25/50 (50%), rhinovirus (hRV) in 2 (4%), hPIV4-hRV co-infection in four (8%) and adenovirus or the OCR43/HKU-1 coronavirus in two (4%) cases; no IAV was detected. Virome sequencing allowed to reconstruct sequences of most PCR-identified rhinoviruses and hPIV-3/human respirovirus-3. COVID-19 was cause to a low proportion of symptomatic RTI among adults. Among COVID-negative participants, symptomatic RTI was predominantly associated with hPIV and hRV. Therefore, respiratory viruses other than SARS-CoV-2 should be considered in the clinical management and prevention of adult RTI in the post-pandemic era.

In Vitro Evaluation of Commercial Probiotic Products Containing Streptococcus salivarius K12 by Assessment of Probiotic Viability and Inhibitory Potency against Respiratory Pathogens

Upper respiratory infections (URI) are the most frequent illnesses, especially in children. The majority of those infections are prescribed broad-spectrum antibiotics, which are associated with various side effects and with the increase in multi-drug-resistant strains. A promising alternative approach is the administration of the probiotic strain Streptococcus salivarius K12 (SSK12) that colonizes the upper respiratory tract (URT) and produces the salivaricins A2 and B, which strongly antagonize the growth of key respiratory pathogens. However, since for food supplements no quality controls of the active probiotic ingredient are mandatory, the efficacy of commercial products containing SSK12 may vary. This study aimed to investigate the in vitro efficacy of several commercial SSK12-containing probiotics, positioned for the prevention of respiratory infections. The parameters evaluated to determine the in vitro efficacy included the viability of the probiotic bacterial strain and the minimum inhibitory dilution (MID) of the probiotic, determined by the agar spot method, against the pathogenic/potential pathogenic bacterial strains Streptococcus pyogenes FF22 and Micrococcus luteus T18. All tests were carried out both 12 and 24 months after manufacturing (AM) for each commercial product. The viability ranged from 9 × 108 to 4.4 × 109 CFU/serving at 12 months AM and from 8.5 × 107 to 2.8 × 109 CFU/serving at 24 months AM. The MID was, in general, positively correlated with the probiotic bacterium viability and varied between the commercial products, ranging from 10−5 to 10−7 at 12 months AM and from 10−4 to 10−7 at 24 months AM. Moreover, the inhibition zones related to the two indicator strains were variable in diameter for different products. The high variation of the in vitro efficacy of commercial products containing SSK12 may explain the different results reported in the literature regarding the clinical benefits of these preparations, and the determination of this parameter may be useful to evaluate the quality of probiotic products containing this bacterial strain.

Nasal vaccines: solutions for respiratory infectious diseases.

Nasal vaccines induce pathogen-specific dual protective immunity at mucosal surfaces and systemically throughout the body. Consequently, nasal vaccines both prevent pathogen invasion and reduce disease severity. Because of these features, nasal vaccines are considered to be a next-generation tool for preventing respiratory infectious diseases, including COVID-19. However, nasal vaccines must overcome key safety concerns given the anatomic proximity of the central nervous system (CNS) via the olfactory bulbs which lie next to the nasal cavity. This review summarizes current efforts to develop safe and effective nasal vaccines and delivery systems, as well as their clinical applications for the prevention of respiratory infections. We also discuss various concerns regarding the safety of nasal vaccines and introduce a system for evaluating them.