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Undoubtedly, vaccination can be one of the promising approaches to control infectious diseases such as the COVID-19 pandemic. Inactivated viral vaccines have a history of "vaccine-induced enhanced disease", which may occur when neutralizing antibodies bind to viral antigens without blocking or clearing the infection. This can cause additional inflammation through the mechanisms described for other respiratory pathogens and lead to acute respiratory distress syndrome. Since the structure and function of SARS-CoV-2 glycoproteins are well known, vaccine manufacturers appear to be careful when inactivating the virus to completely inactivate and maintain the viral epitopes necessary for protective immune induction. It seems that caution should be taken in the usage of inactivated vaccines in children to ensure they are safe and efficacious, vaccinated children should be well monitored and any symptoms should be reported immediately.
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OBJECTIVE: To investigate the immune antibodies in blood specimens of 95 health care workers vaccinated with inactivated 2019-nCoV vaccines and explore the rules and characteristics of production of antibodies after vaccination. METHODS: From Oct 2020 to Jul 2021, the venous blood specimens were collected from 95 health care workers of the 305 Hospital of PLA after the injection of 2 doses of 2019-nCoV vaccines fo30 days, 65 days, 91 days, 6 months and 9 months. SARS-CoV-2 immunoglobin(Ig) M, IgG and titers of neutralizing antibodies and total antibodies were detected by chemiluminescence immunoassay, the results of antibody tests were dynamically analyzed, the immune durability of the antibody, influencing factors and correlation were determined. RESULTS: Almost all of the subjects produced IgG, neutralizing antibody and total antibody, some subjects retained high level of IgM titer. Smoking could affect the production of total antibody. The subjects of the low body weight group produced higher level of IgG, and there was no significant difference when the weight was over 60 kg. The titers of the four types of antibodies decreased significantly at the following time points, and the positive rates of all the antibodies were less than 50% except for IgG after the vaccination for 9 months. CONCLUSION: Specific IgM and IgG, neutralizing antibody and total antibody can be produced after the 2-doses vaccination of inactivated 2019-nCoV vaccines. But the titers and positive rates of the antibodies decrease with time, which means the protective effects on the body decrease. Therefore, in order to improve the autoimmunity against novel coronavirus, one booster vaccination of an inactivated 2019-nCoV vaccine will be necessary after the 2 doses of vaccination for 6 months.
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Objective: We aimed to evaluate the long-term graft functions of kidney transplant recepients (KTR) who have been cured of the COVID-19 and to investigate the role of inactivated COVID-19 vaccine in the clinical course of the disease. Materials and Methods: KTR who had COVID-19 pneumonia between March 2020 and September 2021 were included in the study.. The clinical course of the disease was evaluated in vaccinated patients and compared with those who were not vaccinated. The laboratory information of the patients at the time of admission to the hospital, 6 months and 12 months after the disease was recorded. Results: Of the 83 patients included, 67.5% were male. COVID-19 disease developed in 20 patients after vaccination. Vaccine;it decreased the development of acute kidney injury (AKI) 5.9 fold and hospitalization in the intensive care unit (ICU) 1.4 times fold (p < 0.05). In the follow-up, 10 patients died at the first admission to the hospital and no late death was recorded in the first year. Dialysis treatment was started in 5 patients due to graft loss. Conclusion: In kidney transplant patients, graft dysfunction may develop after COVID-19 infection. However, the inactivated COVID-19 vaccine;it can reduce the risks of hospitalization, AKI, and ICU admission.
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The severe acute respiratory syndrome coronavirus 2 (SARS - CoV2), the causative viral pathogen of the COVID-19 pandemic belongs to the family of Coronaviruses which are positive single stranded RNA viruses. The scientific fraternity has developed and developing various types of vaccines for prevention against COVID-19, such as inactivated virus vaccines, mRNA vaccines, replicating vector protein subunit vaccines, etc., Out of which ten vaccines namely Novovax, Covovax (protein subunit vaccines), Pfizer BNT16b2, Moderna mRNA 1273 (mRNA vaccines), Johnson & Johnson Ad26, Cov2.S, Astrazeneca AZD1222, Covishield (non-replicating viral vector vaccines), Covaxin, Sinopharm BBIBP-CorV, CoronoVac (inactivated vaccines) have been approved for clinical use by WHO. There is an urgent need for SARS-CoV2 specific therapeutics for the treatment of COVID-19 as there is the emergence of various variants such as Alpha, Beta, Gamma, Delta, Omicron, etc. The emergence of variants that possesses immune evading property and spike protein mutation have increased infectivity and more pathogenicity which impelled the need to develop various therapeutics for the treatment of COVID-19. This review compiles the information about potential antiviral candidates in preclinical trials intended for the treatment of COVID-19. The clinical development of such antivirals will be very crucial for the treatment of COVID-19 and also to curb the spread as the present scenario depends on the development of effective prophylactic vaccines.
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Background: The COVID-19 pandemic has led to more than 260 million infections and 55 million deaths as of early December 2021, worldwide. Vaccinating people against COVID-19 is considered as he best approach to overcome the pandemic since COVID 19-vaccines are effective and can reduce the risk of getting and spreading the virus. However, their efficacy and safety in patients with underlying disease such as cancers have not been approved yet. Here we report a cohort study on immunogenicity and safety of the inactivated SARS-CoV-2 vaccine (BBIBP-CorV) in patients with breast cancer, who were vaccinated as a part of a national plan for vaccination of patients with special diseases.
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Objective: The aim of this study is to screen an ideal adjuvant for an inactivated porcine deltacoronavirus(PDCoV) vaccine to induce mucosal immunity and reduce the side effect of the vaccine. We used different mucosal adjuvants to prepare the inactivated PDCoV vaccines. We then used mouse model to evaluate the humoral, cellular and mucosal immune responses induced by the inactivated vaccines via different immunization routes.
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This study aimed to analyze the proliferation characteristics of porcine deltacoronavirus (PDCoV) in suspension cultured porcine kidney cells LLC-PK1, so as to provide Candidate cell for large-scale production of PDCoV inactivated vaccine. LLC-PK1 cells were suspended by gradually decreasing serum method. PDCoV adaptive monoclonal cell lines were screened by limited dilution method. Indirect immunofluorescence method was used to identify the infectivity of PDCoV. The initial cell density, MOI, time of receiving virus collection and TPCK pancreatin concentration were screened to determine the best suspension culture conditions. The suspension cell strain LLC-PK1Sa which can proliferate PDCoV efficiently was screened out;PDCoV can specifically infect LLC-PK1 cells;PDCoV inoculated LLC-PK1Sa cells with a density of 2 x 106 cells.mL-1 according to the MOI of 10-3, When the final concentration of TPCK pancreatin reached 7.5 g.mL-1, the titer of virus solution harvested 48 h after inoculation was the highest. In this study, the efficient proliferation of PDCoV in LLC-PK1Sa suspension cells was realized for the first time, and the suspension culture conditions were preliminarily optimized, which could provide theoretical reference for large-scale production of PDCoV inactivated vaccine.
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This study aims to investigate the protective effect of infected piglets which were immunized with different dose of inactivated porcine epidemic diarrhea virus (PEDV) vaccines. The number of infective virus particles and total virus particles of PEDV with different concentrations were determined, and the mice were immunized with different concentration vaccine prepared as antigen, respectively. The humoral and cellular immune production were determined by ELISA antibody detection method, neutralization test and ELISPOT method. Vaccine with appropriate antigen content was selected to immunize piglets, then the antibody was determined. The relationship between concentrated vaccine and protective effect was studied by challenge experiment. The results showed that, when the antigen dose was equal or greater than 8x106 pfu.mL-1, the inactive vaccine could effectively stimulate mice to produce humoral and cellular immunity. The piglets immunized with 2 mL inactivated PEDV vaccine containing 8x106 pfu.mL-1 antigen could resist diarrhea and continuous viral shedding caused by PEDV challenge. Compared with the total number of virus particles, the number of infectious virus particles was significantly correlated with antibody production (r=0.998 1), and neutralization titer was significantly correlated with piglet protection (r=0.974 7). PEDV inactivated vaccine can provide good immune protection, in which the number of infectious virus particles is the key factor to improve the antibody level. Antibody titer, as an index of humoral immunity, is an important reference for judging immune protection.
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INTRODUCTION: The aim of this study was to examine the descriptive characteristics of randomized controlled trials published in PubMed on COVID-19 vaccines until May 30, 2021. METHODS: Seventy three articles reached by scanning the keywords "vaccine" and "COVID 19" in the PubMed database were reviewed by researchers, 33 randomized controlled trials (RCTs) related to COVID 19 vaccines were included in the study. According to the 17-item questionnaire created by the researchers, the descriptive features of included studies were examined. RESULTS: The total number of investigative authors in 33 RCT articles published in approximately one and a half years from the outbreak of the pandemic was 946, and the average number of authors per article was 28.67+or-18.56.39.3% of the articles were published in The Lancet and 27.2% in The New England Journal of Medicine. Of the vaccines used in the studies, 36.3% mRNA vaccine, 21.2% Inactivated vaccine, 18.1% Recombinant adenovirus vaccine, 12.1% Chimpanzee adenovirus-based vector vaccine, 6% BCG vaccine. 22.5% of vaccines are Phase 1, 12.9% Phase 2, 19.3% Phase 3, 3.2% Phase 4, 32.3% Phase 1-2, 9%,6 of them are Phase 2-3 studies. DISCUSSION AND CONCLUSION: The majority of randomized controlled trials on COVID-19 vaccines are phase 1 and phase 2 trials for mRNA vaccines and inactivated vaccines. Studies have generally been conducted on the adult age group and studies are needed to evaluate the effect of vaccines on the pediatric age group. In studies, the safety of vaccines has been examined more, and there is limited information on efficacy and effectiveness of vaccines.
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Objective: To compare the clinical features of patients with breakthrough infection after getting different kinds of COVID-19 vaccines, in order to provide reference for clinical diagnosis and treatment of such patients.
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Objective: To analysis the production of SARS-CoV-2 antibody among medical staff in Public Health Clinical Center of Chengdu 1 month after a third dose of inactivated vaccine (booster shot), and to compare the SARS-CoV-2 antibody among COVID-19 patients after immunization, in order to analyze the effect of the booster shot.
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The results of the study of the antigenic properties are presented for an experimental sample of emulsified inactivated vaccine against Newcastle disease (ND) and avian infectious bronchitis (IB) supplemented with acrylic acid copolymer (CoAA) as an additional stimulator of the immunogenesis (ND + IB+ CoAA / AB-M4). Experiments with vaccinated chicks evidenced that the experimental inactivated vaccine induces a higher level of immune response compared to the emulsified inactivated vaccine against ND and IB (ND + IB / AB-M4) manufactured according to the standard method.
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The antigenicity of three inactivated emulsified associated vaccines against viruses of chicken infectious bronchitis (IB), Newcastle disease (ND), and egg drop syndrome-76 (EDS-76) based on the oil adjuvant ISA-15 (O/W) was comparatively studied: (1) reference vaccine (IB+ND+EDS-76/ISA-15);(2) experimental vaccine (IB+NB+EDS-76/ISA-15-Nano) with a nanoscale-dispersed oil phase obtained by the use of a high-pressure homogenizer;(3) similar nano-scale vaccine (IB+NB+EDS-76+CoAA/ ISA-15-Nano) additionally supplemented with a copolymer of acrylic acid (CoAA). The in vivo tests of the vaccines on the chicks evidenced that both nano-scale vaccines enhanced the immune response in vaccinated chicks as compared to the reference vaccine and that supplementation with CoAA resulted in the highest postvaccinal antibody titers.
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In the pandemic era of coronavirus disease 2019 (COVID-19), vaccines have been developed and approved to control the pandemic that might reduce the COVID-19 mortality. Transplant recipients are among the high-risk groups and are more susceptible to COVID-19 infection. According to the available data about COVID-19 vaccines, some platform technologies include vector-based, inactivated, protein subunit, virus-like particles, mRNA, and DNA vaccines (1). There are several guidelines about vaccination in immunocompromised individuals for both non-live- and live vaccines. However, there are still limited evidence-based data about COVID-19 vaccines in the hematopoietic stem cell transplantation (HSCT), and establishing a proper recommendation for vaccination in these patients would be challenging (2, 3). Transplant recipients may have shown lesser responses to the vaccines compared with the general population, and it is unknown to what extent the vaccine is effective in this group of patients. Also, in many countries, the vaccination schedule is not adjustable by the patients or physicians, and selecting a particular time window for the best efficacy of immunization is impossible. In this regard, the main concern in the patients treated with immunosuppressive drugs is not worsening symptoms and disease following vaccination. The most critical issue is determining the best time for vaccination to increase its efficacy. Here are some considerations about vector-based, inactivated, and mRNA- nanoparticle vaccines, but most evidence is not based on the results of cohort or clinical trial studies. Before HSCT, patients could receive the COVID-19 vaccine if they are not already immunosuppressed. According to evidence about other inactivated vaccines, such as the influenza vaccine, the interval to start the conditioning regimen could be considered 2 - 4 weeks following the vaccination (4). In autologous HSCT patients, COVID-19 vaccination can be considered 1 - 3 months after transplantation if there has been a community outbreak. If acquiring or transmitting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was well controlled, vaccination could be withheld after six months of transplantation. In the current pandemic, COVID-19 vaccination in allogeneic HSCT patients could be considered at least three months after transplantation. If transmission of SARS-CoV-2 was controlled, vaccination could be withheld after six months of transplantation (4-6). Vaccination of patients with chronic graft versus host disease (cGVHD) receiving less than 20 mg/day prednisolone (or equivalent) for less than 2 weeks, can be considered similar to the HSCT recipients with no GVHD (5). Vaccines in HSCT recipients with active SARS-CoV-2 infection are not effective thus, receiving the vaccine is not recommended. If an HSCT recipient has received the COVID-19 vaccine before HSCT, re-vaccination after transplantation is suggested (6). The administration of the vaccine is considered when the immune system acquired functional competence. Transplant donation should not be delayed due to the vaccination of the donor to protect the patients in case the transplant is urgent (6). It was reported that recipients who have received anti-B cell antibodies might get the vaccine at 3 - 6 months after the administration and four weeks before the next course of B cell-depleting therapy. If this time window was not possible, vaccination can be regarded under B-cell depleting therapy, considering a suboptimal response to the vaccine (7). It should be noted that the effects of rituximab may last for six months or even a year. Also, the decision to order vaccines following the use of rituximab should be based on the level of immunoglobulins and CD19. There is no strong evidence for the short duration of vaccination following the use of rituximab (such as 3 to 6 months). However, despite the low efficacy of the vaccine in such conditions, it is recommended to get the vaccine whenever available. It is reasonable that recipients who have received therapy with antithy
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The new type of coronavirus (SARS-CoV-2), which is transmitted from person to person and causes Severe Acute Respiratory Distress Syndrome (SARS), emerged in Wuhan, China in December 2019. The definitive diagnosis of the coronavirus, which is transmitted from person to person through droplets, is given through PCR-based tests. The continuation of the COVID-19 pandemic has made it necessary to develop an effective vaccine against SARS-CoV-2. Vaccines developed against COVID-19 can be classified as inactivated/live virus vaccines, recombinant protein vaccines/vectored vaccines or RNA/DNA vaccines. This review aims to give information about the molecular structure and genetic features of SARSCoV- 2 virus, laboratory diagnostic methods, potential therapeutic drugs and vaccine studies.
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Following the recommendations from the National Technical Advisory Group (NTAG) on Immunization, the Government of India approved three vaccines - an inactivated vaccine, Covaxin and two non-replicating vector-based vaccines, Covishield and Sputnik V for restricted use in an emergency for pregnant women.(1)The late approval of vaccination of pregnant women was due to a lack of evidence, because pregnant women were excluded from previous COVID vaccination trials. The restricted use of this vaccine recommended by NTAG also complies with the regulations of the Centers for Disease Control and Prevention (CDC), the American College of Obstetricians and Gynecologists, and the American Academy of Pediatrics. (2-4).