Abstract:Antimicrobial resistance (AMR) of bacteria has become crisis of global public health security, World Health Organization (WHO) requires all countries in the world to take positive action and take systematic measures to curb bacterial resistance. In this paper, the occurrence process, risk factors and control strategies of antimicro-bial-resistant bacteria are elaborated, which indicates that the occurrence and spread of AMR are closely related to the use of antimicrobial agents and infection control, suggests that the control of AMR must carry out the clinical application management of antimicrobial agents and infection control at the same time, success can be achieved through coordination with each other.

Abstract:Objective To compare clinical characteristics of imported coronavirus disease 2019 (COVID-19) patients after inoculated/non-inoculated inactivated vaccine (Vero cells) for SARS-CoV-2, provide reference for clinical diagnosis and treatment. Methods Imported COVID-19 patients who had inoculated inactivated vaccine (vaccinated group) and COVID-19 patients from the same countries but didn't inoculate vaccine (non-vaccinated group) who were admitted in Guangzhou Eighth People's Hospital, Guangzhou Medical University from January 4 to April 10, 2021 were chosen. Through comparing the demographic characteristics, clinical symptoms, blood test results and antibodies, chest imaging, as well as treatment methods and prognosis of two groups of patients, clinical chara-cteristics of imported COVID-19 patients after inoculated inactivated vaccine were analyzed and summarized. Results 38 patients in vaccinated group and 38 in non-vaccinated group were included in analysis, the average age of patients was (37.14±8.86) and (39.21±7.66) years old respectively; 58 were males and 18 were females. In the clinical symptoms of two groups, except throat discomfort rate of non-vaccinated group was higher than that of vaccinated group (34.21% vs 13.16%, P < 0.05), there was no significant difference in other clinical symptoms between two groups (P>0.05). There were no significant differences in white blood cells, lymphocytes, liver and kidney function, myocardial enzyme, oxygenation index and D-2 polymer between two groups of patients (P>0.05); there were also no significant differences in the increased proportion of inflammation markers as well as decreased proportion of T lymphocytes CD4⁺ and CD8⁺ between two groups of patients (P>0.05). Within 2 weeks before disease course, positive rate of SARS-CoV-2 antibody IgG in vaccinated group was higher than that in non-vaccinated group, difference was statistically significant (P < 0.05). There was no significant difference in lung imaging between two groups of patients (P>0.05). Conclusion Imported COVID-19 patients after inoculating inactivated vaccine (Vero cells) are mainly young and middle-aged men, most clinical types are nucleic acid test positive and common type, all patients had a good prognosis after treatment. Compared with patients without inoculating inactivated vaccine, patients infected SARS-CoV-2 after inoculating vaccine can produce IgG antibody rapidly in the early stage of disease (within one week), but nucleic acid turns negative for a long time.

Abstract:Objective To analyze the serum antibody IgM and IgG levels of patients with coronavirus disease 2019 (COVID-19), and provide basis for clinical diagnosis and treatment. Methods Chemiluminescence method was used to quantitatively detect the serum antibody levels of hospitalized patients diagnosed with COVID-19 between February 27 and March 5, 2020. Difference in antibody detection positive rates and antibody levels in patients in different disease course (< 7, 7-14, >14 days), different gender and age group (< 18, 18-, 41-, >65 years old) were statistically analyzed. Results Among 550 patients with confirmed COVID-19, 253 were males and 297 were females, with a median age of 61 (50, 69) years. The overall positive rate of IgM and/or IgG antibody was 92.00%, overall positive rates of IgG and IgM were 91.45% and 76.18% respectively. Positive rate of IgM or IgG increased gradually with the progress of the disease, positive rate increased from 31.25% in the early stage to 94.82%. Positive rate of IgG antibody was higher than that of IgM antibody when disease course was more than 14 days (χ²=49.697, P < 0.001). Difference in antibody positive rate among different age groups was statistically significant (χ²=15.339, P=0.002), positive rate was higher in 41- and >65 years old group; there was no significant difference in antibody positive rate between different gender groups (χ²=0.006, P=0.094). IgM was produced within 1-2 weeks after disease onset, reached the peak within 2-3 weeks, and gradually decreased to the normal level after 4 weeks; IgG began to produce at about 1st week after disease onset, reached the peak at about the 3rd week, and still remained stable at 50th days. There was no significant difference in the levels of IgM and IgG among different age groups and gender groups (all P>0.05). Conclusion Positive rate of IgM or IgG in the early stage of disease is relatively low, which increases with the disease process, but antibody level does not show the difference in age and gender, antibody detection can assist diagnosis of COVID-19 patients.

Abstract:Objective To understand antimicrobial resistance of Providencia rettgeri (P. rettgeri) in a hospital, analyze the genetic characteristics of antimicrobial resistance genes of carbapenem-resistant P. rettgeri (CRPR), and provide theoretical basis for clinical prevention and treatment of infection. Methods Antimicrobial susceptibility testing results of P. rettgeri isolated from this hospital from January 2017 to December 2019 were collected, whole genomes of 3 strains of CRPR were detected through high-throughput sequencing, bioinformatics analysis was adopted to explore genetic characteristics. Results A total of 25 strains of P. rettgeri were isolated, 10(40.00%) of which were carbapenem-resistant strains, 7 strains (28.00%) were isolated from department of neurosurgery, urine was the main specimen source (13 strains, 52.00%). 25 strains were all resistant to ampicillin and amoxicillin, resistance rate was 100.00%. Resistance rates to imipenem, ertapenem and meropenem were 36.00%, 40.00% and 28.00% respectively. Genome sequencing of 3 CRPR strains showed that all of them carried 6 antimicrobial resistance genes, including β-lactams (bla_NDM-1, bla_OXA-10 and bla_TEM-1B), macrolides (mph[A], mph[E], msr[E]), trimethoprim (dfrA1), aminoglycosides (aadA1, aadA5, aph[3″]-Ib, aph^[4]-Ia, acc[6']-Ib3, aadB), sulfonamides(sul1), and chloramphenicols(catB8), the genetic structures of the drug-resistant genotypes of bla_NDM-1 and bla_OXA-10 were IS30-bla_NDM-1-ble_MBL-trpF-dsbC-orf-groES-groEL-IS91 and aac(6')-Ib3-dfrA1-aadA1-bla_OXA-10-catB8-aadB respectively. Conclusion Multidrug resistance of P. rettgeri is serious, and there are many types of drug-resistant genes. It is necessary to strengthen the prevention and control of healthcare-associated infection to prevent the spread of antimicrobial-resistant strains.

Abstract:Objective To evaluate the risk factors for surgical site infection (SSI) after total hysterectomy, provide strategies for the prevention and control of SSI. Methods Occurrence and pathogens of SSI in gynecological malignant tumor patients after total hysterectomy in a tumor hospital of Hubei Province From January 2014 to December 2019 was investigated retrospectively, risk factors for SSI were analyzed. Results 978 patients with gynecological malignant tumor underwent total hysterectomy, 94 (9.61%) of whom had SSI, 14 (1.43%) were superficial incisional infection, 80 (8.18%) were organ space infection. Multivariate logistic regression analysis showed that patients with pre-operative hypoproteinemia (OR=2.3, 95% CI [1.3-4.1]) and operation time more than 3 hours (OR=3.4, 95% CI [1.0-10.9]) had an increased risk of SSI, which were independent risk factors for SSI after total hysterectomy. 59 strains of pathogenic bacteria were isolated from surgical infection site, mainly Escherichia coli (62.71%, 37 strains). Conclusion Patients with gynecologic malignant tumor after total hysterectomy have high incidence of SSI, pre-operative hypoproteinemia and operation time are independent risk factors for SSI, corresponding measures should be taken.

Abstract:Objective To evaluate the risk factors for post-operative pneumonia (POP) in patients undergoing hip joint surgery, evaluate the application value of propensity score matching (PSM) in processing of retrospective data. Methods Data of 1 141 patients undergoing hip joint surgery from January 1, 2018 to December 31, 2019 in the department of orthopedics and joint surgery of a hospital were collected, data of patients after hip joint surgery were analyzed by propensity score. Results There were 102 cases of POP among 1 141 hip joint surgery patients, incidence was 8.94%. Before PSM, there was no significant difference in POP incidence between fracture patients and non-fracture patients (P>0.05). Before PSM, there were significant differences in 8 covariates, including gender, age, anesthesia, delirium and dementia, ASA classification, malignant tumor, diabetes and cardiovascular disease between fracture patients and non-fracture patients (all P < 0.05). After PSM, distribution of the above 8 covaria-tes reached equilibrium between two groups (all P>0.05). Logistic multivariate analysis showed that age>65 years old, history of chronic obstructive pulmonary disease and fracture were independent risk factors for POP in hip joint surgery patients (all P < 0.05); compared with general anesthesia, intravertebral anesthesia was an indepen-dent protective factor for POP in hip joint surgery patients (P < 0.05). Conclusion PSM method can effectively reduce the confounding bias among groups in observational study. Fracture is one of the risk factors for POP in hip joint surgery patients.

Abstract:Objective To analyze the risk factors of post-operative infection in patients with liver cancer after hepatectomy, and construct a predictive model for post-hepatectomy infection. Methods Patients who underwent hepatectomy in the First Affiliated Hospital of Soochow University from February 2017 to October 2019 were retrospectively analyzed. General data, laboratory data, operation data and post-operative infection of patients were investigated. Univariate χ² test and multivariate logistic regression were used to determine the independent risk factors for post-operative infection. Based on independent risk factors, logistic risk predictive model was constructed. The area under the receiver operating characteristic (ROC) curve was used to evaluate the predictive effect of the model. In addition, 100 cases of liver cancer patients undergoing surgical resection from January to June in 2020 were selected to establish the validation group, data of modeling group were verified. Results A total of 310 patients were inclu-ded in analysis, 45 cases of healthcare-associated infection (HAI) developed after operation, incidence of HAI was 14.52%, there were 15 cases (33.33%) of surgical site infection, 12 cases (26.67%) of peri-hepatic infection and 18 cases (40.00%) of other distant site infection. Serum albumin (ALB) < 35 g/L, operation time>240 minutes, blood transfusion volume >1 000 mL, drainage time>7 days, ASA score>grade II were independent risk factors for post-operative infection in patients with liver cancer. According to risk factors, risk predictive model was constructed. The area under the ROC curve of predictive model was 0.904, sensitivity, specificity and Youden index were 0.889, 0.766 and 0.655 respectively. Conclusion The model has a good predictive effect on post-operative infection in liver cancer patients after hepatectomy, which can provide a theoretical basis for clinical medical staff to prevent infection in high-risk groups.

Abstract:Objective To analyze the clinical characteristics of patients with Klebsiella pneumoniae liver abscess (KPLA), understand the carrying of virulence gene of Klebsiella pneumoniae (KP), and provide reference for clinical early diagnosis and rational treatment. Methods Clinical data of 34 patients with positive pus culture for bacte-rial liver abscess in the Affiliated Hospital of Jiangsu University from July 2017 to August 2019 were retrospectively analyzed, and were divided into KPLA group and non-KPLA (NKPLA) group. VITEK 2 Compact automatic microbial identification and antimicrobial susceptibility analyzer were used for bacterial identification and antimicrobial susceptibility testing, string test was conducted for hypermucoviscous KP, polymerase chain reaction (PCR) was used to detect antimicrobial resistance genes, capsular serotype and virulence genes, results were statistically analyzed. Results Among 34 cases of bacterial liver abscess cases, 22 patients were with KPLA. Most patients in KPLA group had underlying disease diabetes mellitus, while patients in NKPLA group had underlying disease biliary tract disease or malignant tumor. Only 2 (9.1%) of 22 KP strains were both resistant to ciprofloxacin, levofloxacin and compound sulfamethoxazole, 2 extended-spectrum β-lactamases (ESBLs) resistance genes were detected from 22 strains of KP, which were bla_TEM(36.4%)and bla_CTX-M-1(27.3%). 22 strains of KP were hypervirulent Klebsiella pneumoniae (hvKP), 5 kinds of hypervirulent capsular serotypes were detected, and K1 was the main serotype, accounting for 68.2%. 22 strains of KP all carried virulence genes rmpA, iucA, iroB and iutA. Conclusion KPLA is more common in middle-aged and old men, most are with underlying disease diabetes mellitus, all strains are hvKP, mainly K1 serotype, and carry a large number of virulence genes, resistance rate to commonly used antimicrobial agents is low, but it can carry resistance genes, which needs to be paid great attention by clinicians.

Abstract:Objective To analyze the influencing factors for post-operative intracranial infection after three-dimensional printing-assisted minimally invasive(3DP-MI) treatment for hypertensive intracerebral hemorrhage (HICH), explore the corresponding preventive measures, so as to provide basis for the formulation of prevention and control measures of post-operative intracranial infection. Methods Clinical data of 324 patients who underwent 3DP-MI treatment in neurosurgery department of a tertiary hospital from October 2015 to December 2018 were retrospectively analyzed, according to whether intracranial infection occurred, patients were divided into infection group and non-infection group, general information and surgical treatment course of two groups of patients were compared. Results Among 324 patients undergoing 3DP-MI treatment, 32 (9.87%) had intracranial infection. 19 strains of pathogens were isolated from specimens of patients with intracranial infection, including 9 strains (47.37%) of Gram-negative bacteria, 8 strains (42.10%) of Gram-positive bacteria, and 2 strains (10.53%) of fungi. Univariate analysis on HICH patients undergoing 3DP-MI treatment showed that differences in smoking history, intracranial hemorrhage volume, time from pre-operative skin preparation to operation, operation location, operation duration, times of post-operative thrombolytic therapy, indwelling time of drainage tube, and prophylactic use of antimicrobial agents were all significantly different (all P < 0.05); multivariate logistic regression analysis showed that prophylactic use of antimicrobial agents was the protective factor for the prevention of intracranial infection, while intracranial hemorrhage volume, time from pre-operative skin preparation to operation, operation duration, indwelling time of drainage tube were independent risk factors for intracranial infection. Conclusion Post-operative intracranial infection in HICH patients undergoing 3DP-MI treatment results from a variety of factors, the key to the prevention of intracranial infection is to take effective prevention and control measures during peri-operative period.

Abstract:Objective To understand the effect of comprehensive prevention and control strategy on the prevention and control of surgical site infection (SSI) in breast surgery. Methods From December 2007 to June 2008 and July 2008 to November 2019, prospective and targeted monitoring methods were adopted respectively to investigate and analyze the causes for the increased incidence of 4 cases of SSI during two periods. According to the survey results, targeted prevention and control measures were taken, including control of the impact of new adjuvant chemotherapy, attention to drainage tube maintenance, improvement of operation manipulation to shorten drainage time, special attention of senior physicians and improvement of drainage methods. Results From December 2007 to December 2019, 4 951 cases of breast surgery were monitored, there were 81 cases of SSI, infection rate was 1.64%. Targeted prevention and control measures were taken according to infection characteristics in each period, incidence of SSI decreased significantly (all P<0.01). Incidence of SSI showed a linear decreasing trend (9.09%, 5.39%, 3.59%, 1.90%) in each period of increased infection rate, difference was statistically significant (χ²=8.16, P=0.004). Conclusion According to the characteristics of infection in different periods, in-depth exploration on prevention and control measures as well as finding out key points can effectively prevent and control the occurrence of healthcare-associated infection.

Abstract:Objective To understand the clinical characteristics, bacterial serotypes and antimicrobial resistance of invasive Streptococcus pneumoniae(S. pneumoniae) infection in hospitalized children in a hospital, guide clinical rational antimicrobial use and find effective methods for prevention and treatment of invasive S. pneumoniae infection. Methods Retrospective analysis was performed on clinical data, antimicrobial susceptibility resting results and serotype of S. pneumoniae as well as vaccine serotype coverage of children who were diagnosed with invasive S. pneumoniae infection in a hospital from January 2014 to December 2018. Results 74 children were with invasive S. pneumoniae infection, mainly children in early childhood (55.4%), the main infection site was blood (44.6%). Among 74 strains of S. pneumoniae, 22 were from cerebrospinal fluid, 13 serotypes were divided, the common serotypes were 19F, 19A, 14 and 23F. Isolation rates of penicillin-non-susceptible S. pneumoniae (PNSP) was 56.7% (42 strains), no strain was found to be resistant to linezolid, vancomycin, moxifloxacin and levofloxacin. Resistance rates of strains with different serotypes was significantly different, resistance rates of serotypes 19F and 19A to penicillin, cefotaxime, cefepime and meropenem were higher than other serotypes. The coverage of S. pneumoniae vaccine to S. pneumoniae was 63.5% in PCV7 and 97.3% in PCV13. Conclusion Invasive S. pneumoniae infection is more common in infants and young children in this hospital, serotypes of isolated S. pneumoniae are mainly 19F, 19A, 14 and 23A, PCV13 has a high coverage rate for these serotypes, which can reduce the occurrence of invasive S. pneumoniae infection through vaccination. Serotypes with high prevalence tend to show higher antimicrobial resistance, so antimicrobial agents should be selected rationally according to antimicrobial susceptibility testing results.

Abstract:Objective To analyze the infection status of hepatitis C virus (HCV), human immunodeficiency virus (HIV) and syphilis among drug users in sentinel surveillance in Guiyang City, analyze the related influencing factors of HCV infection, so as to provide basis for targeted prevention and control of HCV infection among drug users. Methods Repeated cross-sectional survey was conducted among drug users in sentinel surveillance in Guiyang City from 2017 to 2019, different drug rehabilitation centers were surveyed each year, monitoring period was from April to July, venous blood was collected for detection of HIV, syphilis and HCV antibody. Infection rates of HCV due to different factors were compared and analyzed. Results From 2017 to 2019, a total of 1 186 drug users were surveyed, HIV infection rates in each year were 0.8%, 0.2% and 0.5% respectively, syphilis infection rates were 7.1%, 8.9% and 9.3% respectively, HCV infection rates were 40.9%, 46.4% and 46.3% respectively. Age ≥ 25 years old (OR=3.334-5.963), female (OR=1.487), sharing injection device (OR=8.107), injecting drugs in recent one month (OR=6.300) and positive syphilis antibody (OR=1.514) were risk factors for HCV infection in drug users. Conclusion In recent years, HIV infection rate among drug users in Guiyang City is low, but HCV infection rate is high, epidemic situation is severe, comprehensive prevention and treatment should be strengthened according to the related influencing factors for HCV in drug users.

Abstract:Objective To explore the correlation between local characteristics (infection width, infection depth, blood supply) of diabetic foot infection (DFI) and systemic infection indicators of patients. Methods Patients with unilateral DFI but without receiving anti-infective treatment in the department of endocrinology of a hospital from January 2016 to May 2019 were retrospectively included in analysis, white blood cell (WBC), neutrophil (N), C-reactive protein (CRP) were collected as indicators of systemic infection, according to the width of infection, infection was divided into toe involvement only, foot involvement only, toe+metatarsophalangeal joint involvement, and toe+metatarsophalangeal joint+foot involvement. According to the depth of infection, infection was divided into superficial infection (involving only skin and subcutaneous tissue), middle infection (involving muscles and tendons), and deep infection (involving bone and joint). According to the ankle brachial index (ABI) of the affected side, blood supply was divided into normal (ABI≥0.9), mild ischemia (0.4≤ABI<0.9) and severe ischemia (ABI<0.4), multivariate analysis of variance and group comparison were adopted for statistical analysis. Results There was no significant difference in patients' WBC, N and CRP among different width of DFI (P>0.05), group comparison indicated that infection width was positively correlated with WBC, N and CRP when infection was widely involved or very limited. There were significant differences in WBC, N and CRP among different depth of infection (P=0.012, 0.010 and 0.003 respectively), group comparison indicated that infection depth was positively correlated with WBC, N and CRP. There were significant differences in WBC, N and CRP in DFI patients with different blood supply (P=0.003, 0.003 and 0.001 respectively), multiple groups comparisons suggested that degree of ischemia in diabetic foot was negatively correlated with WBC, N and CRP of patients. Conclusion Local characteristics of DFI have an important influence on the indicators of patients' systemic infection. DFI width and depth is positively correlated with patients' systemic infection indicators, but was negatively correlated with ischemia.

Abstract:Objective To study the cleaning and disinfection methods as well as effect maintenance time of medicine transfer boxes in pharmacy intravenous admixture service (PIVAS), so as to ensure the safety of finished pro-duct infusion. Methods 64 normally used medicine transfer boxes in a hospital were selected, after cleaning and disinfection with medical disinfectant wipes, visual inspection and microbial detection were carried out at 0, 12, 24, 36 and 48 hours respectively, statistical analysis was conducted. Results After 0 hour of cleaning and disinfection, the qualified rates of visual inspection method and microbial detection method were both 100%. Within 24 hours of cleaning and disinfection, there was no liquid residue and visible dirt in the medicine transfer boxes, qualified rate of microbial detection was more than 95%, no pathogenic bacteria were detected, and the maintenance effect was good. With the extension of time, up to 48 hours, qualified rates of visual inspection method and microbial detection method both decreased significantly, bacterial contamination rate was more than 50%, Escherichia coli was detected at the handles of medicine transfer boxes. Contamination rates of handle (57.50%) and outside side(42.50%) of medicine boxes were higher than inside (18.75%), the top three departments of bacterial contamination were neonatology (46.30%), obstetrics (43.48%) and pediatrics (39.13%). Conclusion Cleaning and disinfecting PIVAS medicine transfer boxes every 24 hours by using medical disinfectant wipes can prevent the occurrence of healthcare-associated infection. For clinical departments with large amount of finished product infusion and frequent use of medicine boxes, such as departments of neonatology, obstetrics and pediatrics, the frequency of cleaning and disinfection of medicine transfer boxes should be properly increased, and attention should be paid to the frequently touched sites of medicine transfer boxes, such as the cleaning and disinfection of the handles of medicine boxes.

Abstract:Objective To explore the application effect of tracer methodology in the investigation of microbial contamination of hemodialysis fluid. Methods Tracer methodology was used to perform on-site tracing for the unqualified events in microbial monitoring on hemodialysis fluid, relevant data were collected and analyzed with quality management tool, the existing root causes were found out, special rectification was made, disinfection and isolation system in hemodialysis room was improved, so as to promote continuous improvement of management quality of healthcare-associated infection and ensure safety of hemodialysis. Results Before the implementation of tracer system, 125 hemodialysis fluid and relevant specimens were taken, 80 of which were qualified, qualified rate was 64.0%. After comprehensive rectification on disinfection, dialysis fluid was continuously monitored and sampled for half a year, 125 specimens were taken, 116 were qualified, qualified rate was 92.8%. There was significant diffe-rence in the qualified rate of hemodialysis fluid and related specimens before and after improvement (P<0.05). Conclusion Tracer methodology is a very effective quality management tool, which can be used for investigation on adverse events of dialysis fluid microbial contamination and continuous quality improvement, and can be promoted and applied in the actual practice of healthcare-associated infection management.

Abstract:Rhino-orbital-cerebral mucormycosis is an extremely dangerous disease with rapid progress, early detection and early diagnosis is the key to improve the cure rate. There are few reports on successful treatment for cerebral mucormycosis through intrathecal injection of posaconazole combined with amphotericin B liposome. In this article, successful treatment of one case of rhino-orbital-cerebral mucormycosis through posaconazole combined with intravenous drip and intrathecal injection of amphotericin B liposome in a hospital is reported and related literatures are reviewed.

Abstract:Since the outbreak of corona virus disease 2019 (COVID-19) in December 2019, the number of confirmed cases worldwide has exceeded 27 million by September 8, 2020. Although the control of epidemic situation in China has achieved initial victory, it still faces the pressure of "external defense input and internal defense rebound". At the same time, due to the different anti-epidemic modes and shortage of medical resources in different countries in the world, some countries are still at the peak of epidemic spread, and a large number of patients still need to strengthen treatment. COVID-19 mainly causes respiratory system injury, and may be accompanied by digestive system symptoms, even digestive system symptoms are the initial symptom in some cases. At the same time, nutritional support plays an important role in the prevention and treatment of patients with COVID-19, good nutritional support scheme is necessary for patients to recover smoothly. Therefore, for the treatment of COVID-19, it is necessary to understand and pay attention to gastrointestinal symptoms of patients, as well as give good nutritional support to patients with COVID-19. In this paper, COVID-19 relevant gastrointestinal symptoms and nutritional therapy scheme are reviewed.

Abstract:The pandemic of coronavirus disease 2019 (COVID-19) seriously threatens human health and development. In response to this global public health event, SARS-CoV-2 vaccine with different techniques has been put into emergency use. This paper introduces the technique of SARS-CoV-2 vaccine, and elaborates the efficacy of COVID-19 vaccine against various mutant strains and its use in high-risk population. It is found that the effectiveness of the existing vaccines to mutant strains has declined to some extent, which suggests that the impact of mutant strains should be paid attention to. The existing vaccines lack sufficient clinical data for the elderly, pregnant women and other high-risk groups, so it is necessary to carry out research on vaccination for high-risk groups as soon as possible.