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Introduction: Biofilm forming Staphylococcus epidermidis is a main causative agent of infections related to medical devices. Purification and evaluation of Gly-TA polysaccharide from a biofilm-forming S. epidermidis as a putative vaccine candidate were the main goals of the current study. Methods: Taking advantage of size exclusion chromatography procedure, glycerol teichoic acid (Gly-TA) was purified from the above-mentioned strain and biochemical analyses including, Fourier Transform Infrared spectroscopy (FTIR) and Proton Nuclear Magnetic Resonance spectroscopy (H1-NMR) were conducted for the recovered polysaccharide. Results: Following PCR confirmation of a S. epidermidis strain, Gly-TA was extracted and its biochemical compositions (i.e. N-acetyl glucose amine residues) were obtained. Conclusion: It is envisaged that Gly-TA polysaccharide could be considered as a putative vaccine to inhibit formation of biofilm by S. epidermidis.

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Introduction: Coronavirus family member SARS- CoV-2 is a current worldwide threat. It enters into the epithelium membrane of respiratory tract with the help of its antigenic spike proteins and cause Coronavirus disease 2019 (COVID -19). Methods: Considering SARS- CoV-2 a potent vaccine or diagnostic candidate, a bioinformatical study was done to determine its structure homology modeling, physiological properties and structure validation with presence of antigenic sites. Results: The surface glycoprotein of SARS-CoV-2 was found to be a stable protein with stereochemically good structure. It also contains 65 antigenic sites. Conclusion: The present study suggests further wet-lab research to develop a vaccine or diagnostic kit using this promising surface glycoprotein.

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Vaccines are a major weapon to control the present COVID-19 pandemic. To achieve this goal, vaccines should confer a robust and long-lasting immunity against SARS-Cov-2. Breakthrough infections and waning immunity are currently observed in patients that recovered from COVID-19 as well as in the vaccinated people. Therefore, a highly effective vaccine is needed to control the present and future outbreaks. Exogenous N-acetyl-5-methoxy-tryptamine or melatonin (MLT) is well known to potentiate an effective and equilibrated immune response in a variety of situation including viral and bacterial infections and vaccines against different microbial and cancer antigens. In regard to anti-SARS-Cov-2 vaccines, beside stimulating specific IgG production as well as specific CD4+ and CD8+ T cells, exogenous MLT might also enhance specific IgA and secretory IgA in the mucosae; hence, preventing the re-infection and/or asymptomatic transmission of the virus. Thus, a study is urgently proposed to evaluate the effects of MLT administration either before or after vaccination against SARS-Cov-2 to evaluate its effect on strength, quality and duration of the immunity. Las but not least, due to its powerful antioxidant and anti-inflammatory properties, MLT administration might minimize the occurrence of adverse events after the vaccination.

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Introduction: Peste des petits ruminants (PPR) or goat plague is a highly contagious viral disease of small ruminants such as sheep and goats with 90% and 100% morbidity and mortality, respectively. This study was aimed at assessing Peste des petits Ruminants Virus (PPRV) specific antibodies in vaccinated pregnant ewes and subsequently the passive immunity in their lambs. Methods: Seventeen apparently healthy sheep (8 pregnant and 9 non pregnant), 2-3 years old and kept under semi-intensive system of management were used. Ewes were vaccinated with the National Veterinary Research Institute PPR vaccine Nigeria strain 75/1 with a virus titre of 10³ Tissue Culture Infectious Dose (TCID). Serum Samples were collected from all the sheep before and after vaccination at interval of two weeks for a period of seven months. The resultant (8) lambs were given birth to, blood sample were collected for four month and sera samples were examined using Competitive ELISA (c-ELISA) for the presence of specific PPR-N antibodies.  Results: The analysed result showed that there was significant difference      (P < 0.05) in the mean PPRV-N specific antibody c-ELISA values (0-13) before vaccination and the percentage competition protective values (> 50%). However, no significant difference (p > 0.05) post-vaccination in both pregnant and non-pregnant ewes was observed throughout the period of the study with mean PPRV-N specific c-ELISA antibodies of 72-86 and 52-86, respectively. The mean PPRV-N specific antibodies values were maintained within the protective value (> 50 %). The result of this study also showed that there was significant difference (P < 0.05) with mean PPRV-N specific c-ELISA antibodies (17.3-29.4; 87.5%) of lambs born to vaccinated pregnant Yankassa ewes from 8 weeks. Conclusion: This study showed that vaccination does not affect pregnancy with Nigeria 75/1 strain of PPR vaccine in ewes as there was no record of abortion. There was a rapid PPR maternal antibody decay in lambs from the 8th week of age as it was observed that at age 10 weeks, only 37.5 % of the lambs had protective titre. It is therefore recommended that lambs can be vaccinated at 9^th week to avoid the window of susceptibility to PPR virus infection.

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The outbreak of SARS-CoV-2 from Wuhan, China in late 2019 and the subsequent worldwide pandemic in 2020 [1]  are pushing scientists to look for urgent and efficient ways of protecting patients and managing positive cases, and a real “race for a cure” is running forward, but also backward! In fact, several epidemiological data in humans suggest that live vaccines (e.g., Bacillus Calmette–Guérin (BCG), measles, oral polio and vaccinia) may enhance nonspecific resistance to other non-targeted infections [2]. Several epidemiological studies have notably shown that BCG vaccine is capable of providing protection against numerous infections, unrelated to tuberculosis in an innate-immune dependent manner [3]. Such non-specific effects implicate both adaptive and innate immune mechanisms, and recent evidence suggests that epigenetic reprogramming of monocytes termed ‘trained immunity’ is a key mechanism which acts as a boosting effect on the innate immune memory [3-6].
Observations suggest that the innate immune system exhibits memory-like features, remembering the first exposure to the vaccine and responds with an emphasized reaction to future infections [3-4]. Particularly, Natural Killer (NK) cells may contribute to these indirect beneficial effects as BCG immunization enhances the cytokine production by human NK cells [7]. Different clinical trials (e.g., BRACE trial in Australia, NCT04327206) are currently underway to investigate the potential benefits of BCG immunization to confer such protection [8]. These trials, due to several paradigms, are essentially restricted to health care providers as an initial step [9].
Moreover, an interesting monocentric trial in the United Arab Emirates was recently published with encouraging results. It compared two groups, comprised of BCG booster-vaccinated healthcare professionals versus unvaccinated professionals. The rate of SARS-CoV-2 infection was compared between the groups, more than 3 months later. The results indicated that the infection rate in the unvaccinated cohort was 8.6% versus 0% in the booster vaccinated cohort (Fisher's exact test P-value = 0.004), highlighting the potential efficiency of this booster BCG vaccine [10]. Finally, regarding the safety of this potential BCG revaccination, a 2021 systematic review encompassing 24 studies has concluded this strategy had no serious adverse events in immuno-competent patients and that such revaccination carries only minimal risks of mild local and systemic reactions [11]. The near future will tell us whether this century-aged BCG vaccine could be a cure of youth for COVID-19 pandemic.

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Sinopharm (BBIBP-CorV) is an inactivated whole-virus COVID-19 vaccine. The phase 3 trial showed an efficacy of up to 78% in preventing symptomatic COVID-19 infections. However, there have been questions raised regarding in its efficacy in older people. In this paper, several lessons are highlighted from this. Firstly, there is a need to take into account the heterogeneity of COVID-19 vaccine studies, such as representation of older people; and whether the results are generalizable to the target population of immunization programmes. Secondly, for older people, antibody responses alone may not indicate the level of protection afforded by vaccines, as cell mediated immunity is a better marker of immunity. Finally, suggestions are given to improve the immune response in older people, such as heterologous vaccination and booster doses.

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Corneal transplantation is among the most successful organ transplantations in humans due to its immune privilege. This owes to lack of blood and lymph vessels and the absence of major histocompatibility complex antigen presenting cells (MHC-II APCs) in the cornea. However, vaccination may trigger MHC-II response as well as antigenic cross reactivity, resulting in allograft rejection. This has been reported earlier in sporadic cases after influenza and yellow fever vaccines. With the rampant vaccination and booster doses against COVID-19, similar episodes of post-vaccination graft rejection in penetrating and lamellar keratoplasties have been reported. We had reported a case of corneal graft rejection post covid vector vaccine which recovered with steroid medications. Allograft rejection with various subtypes of vaccination opens the door to comprehend immune privilege mechanisms and prophylaxis against organ rejection. Clinicians and patients are advised to be alert to this possibility, for prompt recognition as well as treatment of post-vaccination corneal graft rejection.                 

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Many efforts were made to control the COVID-19 pandemic in Iran. Such preventive measures, namely, social distancing, vaccination with foreign vaccines and supporting the domestic vaccine production, on-time diagnostic efforts and treatment of the infected put additional pressure on the health system and the country's budget. The COVID-19 crisis has subsided in the country recently, and now is the time to evaluate and review policies in various domains that were adopted during the crisis. Success in policies and implementation of programs is due to good governance which works in the context of a correct decision-making system. Moreover, efforts to reduce health inequality fall within this context. This note is written to emphasize the importance of policy coherence for the access of people to health through vaccination as a hot current issue in vaccination policymaking. Based on the country’s talented human resources and supporting knowledge-based companies, producing domestic vaccines seems to be a reasonable action that could be done through re-skilling or up-skilling as well as a partnership with pioneer companies. However at this point, one should evaluate and assess the outcomes and achievements of these policies and actions, especially in the field of domestic vaccine production. Moreover, the impact of cost-benefit ratio of such actions on the public health system should be evaluated for preparedness during the future pandemics

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This article explores the subject of mitigating the risks associated with technology transfer in the bioproduction sector such as vaccine industries, which is a challenging and multifaceted process. Based on an examination of case study data, industry reports, and insights gained from over 20 years of bioprocessing experience, it is evident that a comprehensive understanding of the variables involved and meticulous attention to detail are necessary for successful scale-up. Key technological factors include strict regulatory compliance, equipment compatibility, and optimization of process parameters. Organizations can minimize the risks associated with scaling up bioproduction processes and effectively manage the complexities of technology transfer by implementing data-driven strategies and advanced modeling tools.