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Coronavirus disease 2019(COVID-19)has been one of the most concerning public health events in recent years,seriously threatening the lives and health of people worldwide.COVID-19 vaccines are the most cost-effective measure to reduce the influence of severe acute respiratory syndrome coronavirus 2(SARS-COV-2)to the population.Therefore,countries actively develop and vaccinate COVID-19 vaccines,including recombinant protein vaccines,viral vector vaccines,inactivated vaccines,and mRNA vaccines,which occupy the primary market.With the enhancement of variants transmission ability and evasion immunity,the protective effect and durability of COVID-19 vaccines have become the current research hotspots.This paper presents a brief review of the progress of COVID-19 vaccines,intending to provide a reference for the development of COVID-19 vaccines.
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@#Objective To develop,verify and preliminarily apply a fluorescence quantitative PCR(qPCR)method for detection of the virus titer of recombinant measles virus vector severe acute respiratory symptom coronavirus 2(SARS-CoV-2)vaccine.Methods SARS-CoV-2 S gene was amplified using recombinant plasmid pUC57-S351 as the template,and the primer concentration was optimized to develop the qPCR detection method.The specificity and repeatability of the method were verified,and the linear range and limit of detection were determined.The copy number of recombinant virus S gene was detected by the developed qPCR method 1~12 d after continuous culture in bioreactor.Results The qPCR method was developed with the primer concentration of 0.20 μmol/L,which specifically detected the copy number of SARS-CoV-2 S gene.The linear relationship was good(R2= 0.995)at the template concentration ranged from 2 × 10~2 to 2 × 10~8 copies/μL,and the limit of detection was 2 × 10~2 copies/μL;The coefficient of variation(CV)value of 6 repeated detections of copy number of recombinant virus S gene was 2.64%.The copy number of recombinant virus S gene was monitored by the developed qPCR method 1 ~ 12 d after continuous culture in bioreactor,and the results were basically consistent with those detected by cytopathic method.Conclusion The developed qPCR method has good specificity and repeatability,which can be used for virus titer detection of recombinant measles virus vector SARS-CoV-2 vaccine.
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Resumen Antecedentes: Durante la pandemia de COVID-19 se ha reportado incremento de casos de síndrome de Guillain-Barré (SGB). Objetivo: Describir características clínicas y pronóstico de pacientes con SGB antes y durante la pandemia de COVID-19. Material y métodos: Cohorte prospectiva de pacientes con SGB estratificados en dos subgrupos: antes (2018-2019) y durante (2020-2021) la pandemia de COVID-19. Se registraron características clínicas, paraclínicas y defunciones. Se definió como buen pronóstico a la recuperación de la marcha independiente a los tres meses. Resultados: Se incluyeron 201 pacientes (123 durante la pandemia y 78 antes), 69 % del sexo masculino, edad de 45 ± 16 años, 2.5 % de muertes intrahospitalarias. Durante la pandemia se observó mayor frecuencia de la variante desmielinizante (50 %), afección de nervios craneales bulbares (44 % versus 28 %), antecedente de vacunación (16 % versus 0 %) y menor puntuación en la escala MRC (30 ± 16.7 versus 34.3 ± 17.7); se observó aumento de casos de julio a septiembre (38 versus 13). No existieron diferencias significativas en la recuperación de la marcha independiente y número de defunciones. Conclusiones: Durante la pandemia se atendió mayor número de casos de SGB, 16 % asociado a la vacuna contra SARS-CoV-2; los pacientes no presentaron peor pronóstico.
Abstract Background: During the COVID-19 pandemic, an increase in the number of Guillain-Barre syndrome (GBS) cases has been reported. Objective: To describe the clinical characteristics and prognosis of patients with GBS before and during the COVID-19 pandemic. Material and methods: Prospective cohort of GBS patients divided in two subgroups: before (2018-2019) and during (2020-2021) the COVID-19 pandemic. Clinical and paraclinical characteristics, as well as deaths, were recorded. A good prognosis was defined as independent ambulation recovery at three months. Results: Two-hundred and one patients were included (123 during and 78 before the pandemic), out of whom 69 % were males; age was 45 ± 16 years, and there was 2.5 % of in-hospital deaths. During the pandemic, a higher frequency of the demyelinating variant (50 %), bulbar cranial nerves involvement (44 % vs. 28 %), prior history of vaccination (16 % vs. 0 %), and a lower MRC score (30 ± 16.7 vs. 34.3 ± 17.7) were documented. An increase in the number of cases was observed from July to September (38 vs. 13). There were no significant differences in independent ambulation recovery or in the number of deaths. Conclusions: During the COVID-19 pandemic, a higher number of GBS cases were treated, out of which 16 % were associated with the SARS-CoV-2 vaccine; patients treated during the pandemic did not have a worse prognosis.
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Objective:To construct a droplet digital PCR (ddPCR) for quantification of virus particles in recombinant adenovirus-vectored SARS-CoV-2 vaccine.Methods:The genome of SARS-CoV-2 BA.1 strain was used as the target gene. A set of primer and probe was designed based on the conserved sequence of spike protein, and the ddPCR for quantification of virus particles in recombinant adenovirus-vectored SARS-CoV-2 vaccine was established. The linearity, accuracy, specificity, repeatability and durability of the method were verified.Results:The optimal annealing temperature for ddPCR was 63℃. When the number of virus particles was in the range of 5×10 5-2×10 7 VP/ml, the linearity and the recovery rate of the method were good; the specificity of the probe and primer was good; the coefficient of variation (CV) values of the repeatability and the intermediate precision were within 10%; the CV value of the durability was within 15%. When comparing ddPCR with qPCR, the CV values were all within 10%. Conclusions:The established ddPCR had high sensitivity, good stability and strong specificity, suggesting that it could be used for the quantitative detection of virus particles in recombinant adenovirus-vectored SARS-CoV-2 vaccine.
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Children with certain comorbidities and immunocompromising conditions are highly vulnerable to SARS-CoV-2 infection. Vaccination against SARS-CoV-2 is an important strategy to reduce death, critical illness and overall disease burden. With the evolving and increasing transmission of SARS-CoV-2, universal vaccination is essential to achieve this goal. Children with special medical conditions are considered as the priorities for SARS-CoV-2 vaccination. However, vaccine hesitancy towards the implementation of SARS-CoV-2 vaccination currently remains an urgent challenge. In order to promote the sustainable vaccination for those children in Shanghai as well as China, Shanghai municipal center for disease control and prevention, together with the national children’s medical center, children’s hospital of Fudan university and the expert group on immunization planning of the Shanghai preventive medicine association, organized a consensus expert working group to formulate the evidence-based recommendations and implementation suggestions for children with common chronic diseases, allergy history, diseases involving adverse events related to vaccination, and immunocompromising conditions, based on the published evidence of SARS-CoV-2 vaccination for populations and children with special medical conditions.
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ObjectiveTo determine the difference of serum neutralizing antibody levels in healthy persons following the vaccination of inactivated SARS-CoV-2 vaccines. MethodsHealth care workers that received inactivated SARS-CoV-2 vaccines were enrolled in Sichuan provincial people's hospital from January to December 2021. All participants were classified into four groups according to the number and time of vaccination, which were groups of 28 days after the second dose, 180 days after the second dose, 28 days after the third dose and 150 days after the third dose. Serum neutralizing antibody was quantitatively detected by chemiluminescence method. Furthermore, the serum neutralizing antibody levels were compared within and between groups by gender, age and body mass index(BMI). ResultsA total of 349 participants were enrolled in this study, including 113 males and 236 females. The positive rates of neutralizing antibody in the groups of 28 days after the second dose, 180 days after the second dose, 28 days after the third dose and 150 days after the third dose were 74.0%, 25.7%, 100.0% and 100.0%, respectively. In the four groups, neutralizing antibody levels were 10.38 (5.76, 24.00) AU·mL-1, 4.18 (3.00, 6.18) AU·mL-1, 41.18 (25.80, 116.21) AU·mL-1 and 33.33 (18.09, 69.12) AU·mL-1, respectively. The positive rate of neutralizing antibody significantly differed across the groups (P<0.001). Furthermore, neutralizing antibody level in the third dose groups were significantly higher than that in the second dose groups (P<0.001). Neutralization antibody level in young people (<45 years old) was significantly higher than that in middle-aged and elderly people (≥45 years old) in the groups of 180 days after the second dose and 28 days after the third dose (P<0.05). Additionally, neutralization antibody level in normal weight participants was significantly higher than that in overweight and obese participants in the group of 28 days after the second dose (P<0.05). However, no significant difference was found in all groups by gender (P>0.05). ConclusionCompared with two doses of inactivated SARS-CoV-2 vaccine, three doses can significantly induce higher neutralizing antibody and stronger immune protection. Age and BMI have certain effect on the neutralizing antibody.
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@#The Coronavirus Disease 2019(COVID-19) pandemic is having a dramatic impact on human health,lives,and the global economy. The development of a safe and efficacious vaccine is the most effective intervention to protect the population from the disease and limit the spread of the virus. Based on the current guidelines and research progress of severe acute respiratory symptom coronavirus 2(SARS-CoV-2) vaccines in various countries,this review summarized the research progress on non-clinical safety evaluation of SARS-CoV-2 vaccines by referring to the guidelines and relevant literatures over the world,in order to provide a reference for non-clinical research of SARS-CoV-2 vaccines.
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@#Objective To develop and verify a quantitative real-time PCR method for determination of the content of host cell DNA residues in severe acute respiratory symptom coronavirus 2(SARS-CoV-2) inactivated vaccine(Vero cells),in order to better control the safety of products.Methods DNA was extracted from inactivated SARS-CoV-2 vaccine(Vero cells) bulk by magnetic bead separation method,and the DNA residues of host cells were quantitatively analyzed by probetype PCR.The linear range,repeatability,intermediate precision,quantitative limit,specificity,durability and accuracy of the developed method were verified,and the host cell DNA re sidues of 5 batches of inactivated SARS-CoV-2 vaccine(Vero cells)were determined by this method.Results DNA standard curve showed good linearity in the range of 300~0.003 pg/μL(each R~2> 0.99);Relative standard deviations(RSD) of repeatability and intermediate precision verification were less than 20%;The quantitative limit was 0.001 pg/μL;Sample dilution and purified liquid dilution had no interference to detection;The results of 60 min incubation at 53,55,57 ℃ and 56,60,64 min incubation at 55 ℃ showed no significant difference;The recoveries of accuracy verification were 79%~83%,RSD <5%.This method had good adaptability in detecting DNA residues in the bulk of inactivated SARS-CoV-2 vaccine(Vero cells).Conclusion The quantitative realtime PCR method for determination of host cell DNA residues in inactivated SARS-CoV-2 vaccine(Vero cells) has been successfully developed,of which the linearity and range,repeatability,intermediate precision,quantitative limit,specificity,durability and accuracy meet the acceptable standards,and are suitable for the detection and quality control of host cell DNA residues in inactivated SARS-CoV-2 vaccine(Vero cells).
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@#Animal challenge test is an effective means to study the efficacy of severe acute respiratory symptom coronavirus 2(SARS-CoV-2)vaccine. The appropriate animal models and reasonable experimental design play an important role in obtaining efficacy and safety information,as well as supporting clinical trials. At present,common non-clinical animal models include transgenic mice,non-human primates,hamsters,ferrets and so on. This paper reviews the common animal models used in non-clinical trials and the problems encountered in their application.
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Effect of amantadine dimer adjuvant on humoral immune response induced by SARS-CoV-2 protein vaccine in mice@#Objective To investigate the effect of amantadine dimer adjuvant on humoral immune response induced by SARS-CoV-2 crown protein vaccine in mice.Methods The amantadine dimer was synthesized by substitution reaction ligation,hydrolytic acidification reaction ligation and amide condensation reaction ligation,with which as adjuvant,female BALB/c mice were immunized with the receptor-binding domain(RBD).The mice were randomly divided into five groups,six for each as follows:R6A+RBD group[21 μg(0.033 μmol)amantadine dimer+10 μg RBD],Ada+RBD group[10 μg(0.066 μmol)amantadine+10 μg RBD],Alu+RBD group(35 μg aluminum adjuvant+10 μg RBD),RBD group(10 μg RBD)and Blank group(0.9% normal saline),which were immunized i.m.on day 0,14 and 28 respectively.Serum samples were collected from tail vein of mice 7 d after the second dose and 14 d after the last dose and determined for specific IgG antibody levels by ELISA.Results The amantadine dimer was purified by thin layer chromatography(TLC)and identified by electrospray ionization-MS(ESI-MS)positive/negative ion mode.After two times of immunization,the antibody levels in sera at various dilutions of mice in R6A+RBD group were all higher than those of Ada+RBD group,while lower than those of Alu+RBD group.However,after three times of immunization,the antibody levels in sera at various dilutions of mice in R6A+RBD group were all significantly higher than those of Ada+RBD and Alu+RBD groups(each F > 30,each P < 0.000 1 and each P < 0.01).Conclusion Amantadine dimer adjuvant enhanced humoral immune response induced by SARS-CoV-2 protein vaccine in mice with good adjuvant effect,which may be used as an alternative adjuvant.This strategy based on existing drug transformation provided a new idea for the development of novel adjuvants.
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Sequential immunization is one of the special means to solve the shortage of vaccines, respond to SARS-CoV-2 variants and improve the efficacy of vaccines in the current pandemic period. This article mainly reviewed five sequential immunization strategies using the vaccines authorized by World Health Organization: priming with inactivated vaccine and boosting with recombinant protein vaccine, vector vaccine or mRNA vaccine; priming with vector vaccine and boosting with mRNA vaccine; prime-boost immunization with mRNA vaccines produced by different manufactures. Results of the related studies showed that heterologous sequential immunization strategies were safe and effective, and higher immunogenicity and efficacy could be achieved by sequential immunization. In addition, sequential immunization could provide certain protective effects against SARS-CoV-2 variants.
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【Objective】 To investigate the immune status of blood donors in Yangzhou area after SARS-COV-2 vaccinating. 【Methods】 Among 112 voluntary blood donors from August 29 to September 22, 2021, 111 were vaccinated with SARS-COV-2 vaccine.IgM antibody(by enzyme-linked immunocapture method), IgG antibody(by indirect method of combined immunoassay)and IgG antibody titer were detected. 【Results】 A total of 99.11% (111/112 ) voluntary blood donors were vaccinated, two-shot(n=103), one-shot(n=1) and three-shot (n=7) accounting for 91.96%, 0.89% and 6.25%, respectively.Eighty-eight (78.57%) were positive for IgG antibodies, and 14 (12.5%) were positive for IgM antibodies.No statistically significant difference was found in IgG and IgM positive yielding between males and females (P>0.05). The proportion (0.89%, 1/112) of positive IgM in blood donors with blood type A was significantly lower than that of other blood types (P<0.01). The IgG antibody titer of blood donors maintained rather high level within 6 months after vaccinating.47.66% of the donors presented antibody titer more than 160, and 5.60% had IgM antibody been detected within 1 month after vaccinating. 【Conclusion】 At present, the SARS-COV-2 vaccination effect in China is generally good.Since IgG antibodies cannot be detected after 6 months, it is suggested to perform IgG antibody testing for donors who have completed the second dose for more than 6 months.For those IgG antibody negative, booster shots should be conducted.For donors with high IgG antibody titer, their plasma may be considered to replace with COVID-19 convalescent plasma for the treatment of patients with rapid disease progression, or severe/critically ill patients diagnosed with COVID-19, so as to avoid the risk of COVID-19 re-spreading during convalescent plasma collection in blood centers. For blood donors with positive IgM antibodies, it is recommended to follow up the NAT results to minimize the risk of transmission.
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Organ transplant recipients are at a high risk of infection with high hospitalization rate, critical rate and fatality, due to low immune function caused by taking immunosuppressants for a period of long time after organ transplantation. Currently, vaccination is recognized as an effective approach to prevent infection. Organ transplant recipients may be vaccinated according to individual conditions. However, the sensitivity to vaccines may decline in organ transplant recipients. The types, methods and timing of vaccination have constantly been the hot spots of clinical trials. In this article, the general principles, specific vaccines and SARS-CoV-2 vaccines of vaccination in organ transplant recipients were briefly reviewed, aiming to provide reference for the vaccination of organ transplant recipients. Moreover, current status of SARS-CoV-2 vaccination for organ transplant recipients was illustrated under the global outbreak of novel coronavirus pneumonia pandemic.
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Objective:To detect IgG and neutralizing antibodies response to SARS-CoV-2 vaccine by comparing enzyme-linked immunosorbent assay (ELISA), commercial magnetic particle chemiluminescence assay(CLIA) and neutralization test(NT).Methods:ELISA, CLIA and NT were used to detect 143 healthy people before and after 28 days immunization with 2 doses of SARS-CoV-2 vaccine, and calculate the positive conversion rate, quantitative results and analysis the consistency of the three methods.Results:The positive conversion rate of SARS-CoV-2 vaccine antibody detected by ELISA, CLIA and NT were respectively 97.9%, 98.6% and 85.3%. The geometric mean of the highest dilution of the serum quantitatively detected by ELISA was 586.6; The mean of CLIA S/CO value was 11.26; The geometric mean titer of the NT was 7.6. The correlation coefficient between ELISA, CLIA and NT were respectively 0.69( P<0.01) and 0.65( P<0.01), and the correlation coefficient between ELISA and CLIA was 0.79( P<0.01). Conclusions:The three methods all detected high levels of antibodies response to SARS-CoV-2 vaccine immunization. ELISA and CLIA are more consistent to detect IgG antibody, and have a good correlation with the quantitative detection results of the NT.
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Abstract Since the emergence of the new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in China at the end of 2019, when its characteristics were practically unknown, one aspect was evident: its high contagion rate. This high infection rate resulted in the spread of the virus in China, Europe, and, eventually, the rest of the world, including Mexico. At present, around 9 million people are infected, and around 470,000 have died worldwide. In this context, the need to generate protective immunity, and especially the generation of a vaccine that can protect the world population against infection in the shortest possible time, is a challenge that is being addressed in different countries using different strategies in multiple clinical trials. This opinion article will present the evidence of the induction of immune response in some of the viruses of the coronavirus family before COVID-19, such as SARS-CoV and MERS-CoV (Middle East respiratory syndrome coronavirus). The information collected about the induction of an immune response by SARS-CoV-2 will be presented, as well as a description of the vaccine candidates reported to date in the various ongoing clinical trials. Finally, an opinion based on the evidence presented will be issued on the potential success of developing vaccine prototypes.
Resumen Desde el surgimiento del nuevo coronavirus SARS-CoV-2 (coronavirus tipo 2 del síndrome respiratorio agudo severo) en China a finales del año 2019, cuando todavía era desconocido prácticamente en todos los aspectos, una característica era evidente: el alto índice de contagio entre la población. Esto resultó en la expansión del virus en China, Europa y, finalmente, en el resto del mundo, incluyendo México. Actualmente, alrededor de 9 millones de personas están infectadas, y han muerto cerca de 500,000 en todo el mundo. En este contexto, la necesidad de generar inmunidad protectora y, sobre todo, el desarrollo de una vacuna que pueda proteger a la población mundial contra la infección en el menor tiempo posible, es un reto que se está abordando en distintos países utilizando diversas estrategias en múltiples ensayos clínicos. En este artículo de opinión se presentan las evidencias de la inducción de respuesta inmunitaria con algunos de los virus de la familia de coronavirus previos al SARS-CoV-2, como el SARS-CoV (coronavirus del síndrome respiratorio agudo severo) y el MERS-CoV (síndrome respiratorio por coronavirus de Oriente Medio). Además, se presenta lo reportado hasta el momento acerca de la inducción de respuesta inmunitaria por el SARS-CoV-2, así como una descripción de los candidatos a vacunas informados hasta el momento en los distintos ensayos clínicos en curso. Finalmente se emite una opinión, basada en las evidencias presentadas, acerca del éxito potencial de los prototipos de vacunas en desarrollo.
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Animals , Humans , Pneumonia, Viral/prevention & control , Viral Vaccines , Coronavirus Infections/prevention & control , Pandemics/prevention & control , Betacoronavirus/immunology , Pneumonia, Viral/immunology , Pneumonia, Viral/epidemiology , Coronavirus Infections/immunology , Coronavirus Infections/epidemiology , Severe Acute Respiratory Syndrome/immunology , Severe Acute Respiratory Syndrome/prevention & control , Severe acute respiratory syndrome-related coronavirus/isolation & purification , Severe acute respiratory syndrome-related coronavirus/immunology , Middle East Respiratory Syndrome Coronavirus/isolation & purification , Middle East Respiratory Syndrome Coronavirus/immunology , Betacoronavirus/isolation & purification , COVID-19 Vaccines , SARS-CoV-2 , COVID-19 , 2019-nCoV Vaccine mRNA-1273ABSTRACT
El objetivo de este artículo es proporcionar una guía que sirva para la interpretación y seguimiento de los esfuerzos que se están desarrollando en todo el mundo con el objetivo de obtener una vacuna que pueda generar inmunidad contra el nuevo coronavirus SARS-CoV-2 de 2019, el agente causante de la enfermedad por coronavirus denominada COVID-19. Cinco meses después de haber sido detectada la enfermedad, ya hay 102 vacunas en distintos estadios de desarrollo, registradas por la Organización Mundial de la Salud (OMS), correspondientes a 8 plataformas vacunales con diferentes estrategias, y todos los días aparecen nuevas. Esto representará un enorme desafío de organismos internacionales, para la evaluación, comparación y selección de aquellas que cumplan con los criterios regulatorios indispensables de seguridad y eficacia y que, por otro lado, puedan ser producidas en cantidades suficientes para abastecer la demanda mundial. (AU)
The objective of this article is to provide a guide to help the interpretation and monitoring the efforts that are being carried out worldwide to obtain a vaccine that will be able to generate immunity against the new 2019 SARS-CoV-2 coronavirus, the viral agent causes the disease named COVID-19. Five months after the disease was detected, there are already 102 vaccines at different stages of development, registered by World Health Organization (WHO), corresponding to 8 vaccination platforms base on different strategies, and every day new ones appear. This will represent a huge challenge for international organizations, to evaluate, compare and selects those that will meet the essential regulatory criteria of safety and efficacy and that, would be able to be produced in enough quantities to supply the worldwide demand. Key words: SARS-Cov-2 vaccine, vaccine platform, COVID-19 strategy, attenuated virus, viral vector, viral proteins, viral DNA, viral RNA, nucleic acids, viral like particles, WHO. (AU)