Prevalencia de anticuerpos contra SARS-CoV-2 en pacientes con cáncer y trabajadores de la salud vacunados con dos dosis de BNT162b2 o AZD122. Análisis de propensión / Prevalence of SARS-CoV-2 antibodies in cancer patients and healthcare workers vaccinated with two doses of BNT162b2 or AZD122. A propensity analysis

Resumen Antecedentes: La vacunación es la intervención más efectiva para reducir la carga de enfermedad por SARS-CoV-2; sin embargo, persisten brechas en el conocimiento en relación con la respuesta inmunológica de los pacientes con cáncer (PC). Objetivos: Evaluar la respuesta humoral (anticuerpos anti-S) en PC y trabajadores de salud (TS) vacunados con dos dosis de la vacuna BNT162b2 o AZD122. Material y métodos: Se cuantificaron anticuerpos poliespecíficos contra la proteína de espiga de SARS-CoV-2 (anti-S) y se efectuó una puntuación de propensión 1:1 para equilibrar las características basales. Se realizaron regresiones logísticas múltiples para evaluar el efecto de las variables relacionadas con la respuesta humoral. Resultados: Se incluyeron 127 PC (22 %) y 439 TS (78 %). Ambas poblaciones desarrollaron anticuerpos anti-S en respuesta a la vacunación. La vacuna de ARNm (BNT162b2) se asoció a mayor probabilidad de mostrar concentraciones de anticuerpos anti-S ≥ 1000 UI/mL, mientras que el cáncer activo se relacionó con menor probabilidad de presentar títulos altos de anticuerpos. Conclusiones: La vacuna BNT162b2 se asoció a respuesta humoral mayor. Es necesario contar con más información y estrategias de vacunación en pacientes inmunosuprimidos. Es relevante la selección de los mejores biológicos para esta población y considerar las características individuales.

Abstract Background: Vaccination is the most effective intervention for reducing the burden of SARS-CoV-2-related disease; however, gaps in knowledge regarding cancer patients (CPs) immune response persist. Objectives: To evaluate the humoral response (anti-S antibodies) in CPs and healthcare workers (HCWs) vaccinated with two doses of BNT162b2 or AZD122 vaccines. Material and methods: Polyspecific anti-SARS-CoV-2 spike protein (anti-S) antibodies were quantified, and a 1:1 propensity score was used to balance baseline characteristics. Multiple logistic regressions were carried out to evaluate the effect of humoral response-related variables. Results: One-hundred and twenty-seven CPs (22 %) and 439 HCWs (78 %) were included. Both populations developed anti-S antibodies in response to vaccination. The mRNA-based vaccine (BNT162b2) was associated with higher odds of having anti-S antibody titers ≥ 1,000 U/mL, while active cancer was related to a lower probability of developing high antibody titers. Conclusions: The BNT162b2 vaccine was associated with a higher humoral response. It is necessary for more information and vaccination strategies to be available for immunosuppressed patients in order to select the best biologics for this population based on individual characteristics.

Trends of humoral immune responses to heterologous antigenic exposure due to vaccination & omicron SARS-CoV-2 infection: Implications for boosting

Background & objectives: Vaccination and natural infection can both augment the immune responses against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but how omicron infection has affected the vaccine-induced and hybrid immunity is not well studied in Indian population. The present study was aimed to assess the durability and change in responses of humoral immunity with age, prior natural infection, vaccine type and duration with a minimum gap of six months post-two doses with either ChAdOx1 nCov-19 or BBV152 prior- and post-emergence of the omicron variant. Methods: A total of 1300 participants were included in this observational study between November 2021 and May 2022. Participants had completed at least six months after vaccination (2 doses) with either ChAdOx1 nCoV-19 or an inactivated whole virus vaccine BBV152. They were grouped according to their age (? or ?60 yr) and prior exposure of SARS-CoV-2 infection. Five hundred and sixteen of these participants were followed up after emergence of the Omicron variant. The main outcome was durability and augmentation of the humoral immune response as determined by anti-receptor-binding domain (RBD) immunoglobulin G (IgG) concentrations, anti-nucleocapsid antibodies and anti-omicron RBD antibodies. Live virus neutralization assay was conducted for neutralizing antibodies against four variants – ancestral, delta and omicron and omicron sublineage BA.5. Results: Before the omicron surge, serum anti-RBD IgG antibodies were detected in 87 per cent participants after a median gap of eight months from the second vaccine dose, with a median titre of 114 [interquartile range (IQR) 32, 302] BAU/ml. The levels increased to 594 (252, 1230) BAU/ml post- omicron surge (P<0.001) with 97 per cent participants having detectable antibodies, although only 40 had symptomatic infection during the omicron surge irrespective of vaccine type and previous history of infection. Those with prior natural infection and vaccination had higher anti-RBD IgG titre at baseline, which increased further [352 (IQR 131, 869) to 816 (IQR 383, 2001) BAU/ml] (P<0.001). The antibody levels remained elevated after a mean time gap of 10 months, although there was a decline of 41 per cent. The geometric mean titre was 452.54, 172.80, 83.1 and 76.99 against the ancestral, delta, omicron and omicron BA.5 variants in the live virus neutralization assay. Interpretation & conclusions: Anti-RBD IgG antibodies were detected in 85 per cent of participants after a median gap of eight months following the second vaccine dose. Omicron infection probably resulted in a substantial proportion of asymptomatic infection in the first four months in our study population and boosted the vaccine-induced humoral immune response, which declined but still remained durable over 10 months

Effect of amantadine dimer adjuvant on humoral immune response induced by SARS-CoV-2 protein vaccine in mice / 中国生物制品学杂志

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.

Preparation and immunogenicity evaluation of mRNA vaccine against porcine epidemic diarrhea / 生物工程学报

Porcine epidemic diarrhea (PED) is a highly contagious disease that causes high mortality in suckling piglets. Although several licensed inactivated and live attenuated vaccines were widely used, the infection rate remains high due to unsatisfactory protective efficacy. In this study, mRNA vaccine candidates against PED were prepared, and their immunogenicity was evaluated in mice and pregnant sows. The mRNA PED vaccine based on heterodimer of viral receptor binding region (RBD) showed good immunogenicity. It elicited robust humoral and cellular immune responses in mice, and the neutralizing antibody titer reached 1:300 after a single vaccination. Furthermore, it induced neutralizing antibody level similar to that of the inactivated vaccine in pregnant sows. This study developed a new design of PED vaccine based on the mRNA-RBD strategy and demonstrated the potential for clinical application.

Identificação, caracterização e determinação de padrões da resposta imune de epítopos imunogênicos de Plasmodium vivax / Identification, characterization and determination of immune response patterns of immunogenic epitopes of Plasmodium vivax

O Plasmodium vivax representa um grande desafio no controle da malária devido a sua vasta distribuição ao redor do globo, grande frequência de infecções sub microscópicas e habilidade de induzir recaídas em consequência das formas evolutivas que podem ficar latentes no fígado por longos períodos (hipnozoítos). O recente aumento de cepas de P. vivax resistentes aos fármacos disponíveis, a evolução de formas mais virulentas do parasito e a produção precoce de gametócitos, característica desta espécie, contribuem para classificar a malária vivax como um problema de saúde pública que merece atenção. Ainda que reconhecido por suas características biológicas peculiares e pelo agravamento recente de sua virulência, poucos investimentos têm sido feitos no desenvolvimento de ferramentas de controle para vivax. Portanto, o presente estudo teve como objetivo identificar e caracterizar novos alvos potenciais utilizando amostras de diferentes áreas endêmicas ao redor do mundo (Brasil, Mali, Camboja e Estados Unidos da América). Para tanto, investigamos e caracterizamos uma proteína recém descoberta na urina de pacientes naturalmente infectados (PvVir14); e descrevemos o potencial imunogênico de epítopos de células B de uma das proteínas mais bem caracterizadas de P. vivax, a PvAMA-1. Anti-IgG circulantes contra PvVir14 apareceram em 61% e 34.5% dos indivíduos do Brasil e Camboja, respectivamente, enquanto que indivíduos de Mali (infectados com falciparum e não expostos a vivax), tiveram 0% de reconhecimento. Ainda, os níveis de anti-PvVir14 correlacionaram-se com aqueles contra outros antígenos de vivax já bem caracterizados, como a PvCSP e a PvDBP, que foram reconhecidos por 7.6% e 42% dos indivíduos respectivamente. Com relação ao perfil celular, indivíduos sororreativos para PvVir14 apresentaram níveis significativamente maiores de células B atípicas circulantes (CD 21- CD 27-), sugerindo que tal tipo celular possa estar ligado à resposta anti-PvVir14. Entre as células T, os níveis de CD4+ e CD8+ diferiram entre indivíduos com e sem anticorpos contra PvVir14 (menor e maior expressão, respectivamente), enquanto que os níveis de células NKT foram mais expressivos em indivíduos sem anti-PvVir14. Se tratando da PvAMA-1, a antigenicidade dos peptídeos com epítopos para células B previamente selecionados foi avaliada através de múltiplos ensaios sorológicos utilizando amostras de indivíduos com infecção aguda por P.vivax do norte do Brasil. Os peptídeos sintéticos foram reconhecidos por 45.5%, 48.7% e 31.2% (PI, PII e PII, respectivamente) dos indivíduos selecionados para o estudo. Quando sintetizados em conjunto (tripeptídeo), a reatividade aumentou para 62%, porcentagem comparável àquela obtida pela proteína em sua forma e tamanho originais (57%). Além disso, a reatividade anti-IgG conta o tripeptídeo foi reduzida em 42% pós-depleção, indicando que tais epítopos podem ser responsáveis por parte considerável da imunogenicidade da proteína. Esses resultados representam uma excelente perspectiva na identificação de novos alvos com potencial imunogênico para compor uma vacina, ou auxiliar no desenvolvimento de outras medidas de controle, como testes diagnósticos, já que contemplar diversos alvos do ciclo de vida do parasito parece ser a chave para alcançar a resposta robusta e protetora que uma vacina contra a malária vivax precisa para ter sucesso.

Plasmodium vivax is a major challenge for malaria control due to its wide geographic distribution, high frequency of submicroscopic infections, and ability to induce relapses due to the latent forms present in the liver (hypnozoites). The recent increase in drug-resistant P. vivax strains, the evolution toward more virulent forms and the early production of gametocytes adds up to make P. vivax malaria a public health issue of increasing importance. Besides its tricky biological features and new awareness of its virulence, minimal investments have been made in vaccine discovery for P. vivax. Given that, this study aimed to discover and characterize potential new targets for future vaccine development using samples from different endemic areas around the world (Brazil, Mali, Cambodia and United States of America). For this purpose, we investigated and characterized a novel protein recently discovered in the urine of naturally infected subjects (PvVir14) and described the immunogenic potential of peptides from a well-known vivax protein (PvAMA-1), which has been proved to have important B cell epitopes that can induce specific immune response. Circulating antibodies against PvVir14 appeared in 61% and 34.5% of subjects from Brazil and Cambodia, respectively, versus none (0%) of the P. falciparum-infected subjects from Mali who have no exposure to P. vivax. PvVir14 antibody levels correlated with those against other well-characterized sporozoite/liver (PvCSP) and blood stage (PvDBP-RII) antigens, which were recognized by 7.6% and 42% of Brazilians, respectively. Concerning the cellular immune profiling of Brazilian subjects, PvVir14 seroreactive individuals displayed significantly higher levels of circulating atypical (CD21− CD27−) B cells, raising the possibility that atypical B cells may be contribute to the PvVir14 antibody response. Among T cells, CD4+ and CD8+ levels differed (lower and higher, respectively) between subjects with versus without antibodies to PvVir14, while NKT cell levels were higher in those without antibodies. As for PvAMA-1, the antigenicity of the selected B-cell peptides was assessed by multiple serological assays using sera from acute P.vivax infected subjects. The synthetic peptides were recognized by 45.5%, 48.7% and 32.2% of infected subjects for peptides I, II and III respectively. Moreover, when synthetized together (tripeptide), the reactivity increases up to 62%, which is comparable to the reactivity found against the whole protein PvAMA-1 (57%). Furthermore, IgG reactivity against the tripeptide after depletion was reduced by 42%, indicating that these epitopes may be responsible for a considerable part of the protein immunogenicity. These results represent an excellent perspective on discovering new targets with immunogenic potential to compose a vaccine, or even to assist the development of other control measures, such as diagnostic tools, since contemplating several targets seems to be the key to achieving a robust and protective response that a malaria vaccine needs to be successful.

Terapia genética de injeção intravítrea de rAAV2-ND4 para neuropatia óptica hereditária de Leber: uma revisão sistemática / rAAV2-ND4 intravitreal injection gene therapy for Leber's hereditary optic neuropathy: a systematic review

RESUMO A neuropatia óptica hereditária de Leber é uma doença mitocondrial hereditária neurodegenerativa. A taxa potencial de recuperação espontânea é controversa na literatura. A terapia genética tem sido estudada como suporte aos pacientes. O objetivo desta revisão foi avaliar qualitativamente a segurança, os efeitos adversos e a eficácia da terapia gênica disponível. Trata-se de uma revisão sistemática de artigos indexados nas bases de dados PubMed®, Biblioteca Virtual em Saúde, SciELO, Cochrane, ScienceDirect, Scopus e Lilacs no primeiro semestre de 2021. Os critérios de inclusão e filtros foram: artigos relacionados ao tema, estudos randomizados, ensaios clínicos, trabalhos em humanos, últimos 5 anos, nas línguas portuguesa, inglesa e espanhola e texto completo disponível gratuitamente. Os parâmetros de exclusão foram: artigos duplicados, fuga ao tema, artigos de revisão, trabalhos não disponíveis e que fugiam aos critérios de inclusão. O coeficiente de kappa foi 0,812. A terapia não apresentou efeitos adversos sérios em nenhum dos artigos selecionados, e os efeitos menores sofreram 100% de remissão espontânea após o tratamento. Apesar de NAbs terem sido encontrados no soro de alguns pacientes, não houve associação entre a resposta imune adaptativa e a injeção do vetor viral. O tratamento foi eficaz na melhora da acuidade e campo visual. Vários estudos confirmaram a eficácia da terapia gênica, em doses baixas e médias, na melhora da acuidade visual e também sobre os efeitos adversos comuns relacionados à altas doses. A resposta imune humoral e a variação dos NAbs no soro foi citada em mais de um artigo. A terapia foi eficaz na melhora da acuidade visual e os efeitos adversos que surgiram foram tratados facilmente. No entanto, a resposta imune humoral ainda precisa ser estudada.

ABSTRACT Leber's Hereditary Optic Neuropathy (LHON) is an inherited neurodegenerative mitochondrial disease. The potential rate of spontaneous recovery is controversial in the literature. Gene therapy has been studied to support patients. The objective of this review was to qualitatively assess the safety, adverse effects, and efficacy of available gene therapy. This is a systematic review of articles indexed in PubMed®, VHL, SciELO, Cochrane, ScienceDirect, Scopus, and Lilacs databases, in the first half of 2021. Inclusion criteria and filters were: articles related to the topic, randomized studies, clinical trials, work in humans, last 5 years, in Portuguese, English, and Spanish and full text available for free. The exclusion parameters were: duplicate articles, not related to the topic, review articles, not available works, and works that did not meet the inclusion criteria. The kappa coefficient was 0.812. The therapy had no serious adverse effects in any of the selected articles, and minor effects experienced 100% spontaneous remission after treatment. Although NAbs were found in the serum of some patients, there was no association between the adaptive immune response and the injection of the viral vector. The treatment was effective in improving acuity and visual field. Several studies have confirmed the effectiveness of gene therapy, at low and medium doses, in improving visual acuity and also on common adverse effects related to high doses. The humoral immune response and the variation in serum NAbs was cited in more than one article. The therapy was effective in improving visual acuity and the adverse effects that arose were easily treated. However, the humoral immune response still needs to be studied.

Efficacy of some avian influenza H5 vaccines against local highly pathogenic avian influenza viruses subtype H5N8 isolated in 2018 and 2020 in Egypt

Commercial inactivated avian influenza H5 vaccine is used as an essential control strategy for avian influenza disease in Egypt. Since the initial outbreaks of highly pathogenic avian influenza H5N8, the virus has diverged with new genotypes and variant viruses continuing to emerge which mainly stand behind vaccination failure. In the present work, four different commercial avian influenza vaccines were inoculated in specific pathogenic free chickens for assessing its efficacy against local highly pathogenic avian influenza H5N8 virus isolated in 2018 and 2020. Two hundred and forty specific pathogenic free chickens were clustered into four groups; each group was inoculated with the corresponding vaccine (60 specific pathogenic free chickens/vaccine). Sixty specific pathogenic free chicks were kept as control unvaccinated group. Sera collected from vaccinated chicken groups at 3rd and 4th week post vaccination were examined for calculating neutralizing antibodies using heterologous highly pathogenic avian influenza H5N8 2018 and 2020. At 4th week post vaccination, vaccinated chickens were challenged; moreover, oropharyngeal swabs were collected from challenged vaccinated chickens to calculate the viral shedding. Our findings revealed the groups vaccinated with vaccine code no 1 and 2 that contains two vaccine strains (H5N1 and H5N8) of local origin exhibited the highest hemagglutination inhibition titer, protection (percent) and reduction in viral shedding titer when examined by highly pathogenic avian influenza H5N8 2018 while, vaccine code no 3 induced lower antibody response, protection (percent) and reduction in viral shedding, but still within satisfactory level when compared to previous groups. When highly pathogenic avian influenza H5N8 2020 was used, it was found the seroconversion rate, protection (percent) and mean titer of reduction of viral shedding decreased in comparison to those recorded for highly pathogenic avian influenza H5N8 2018. Vaccine code no 4 was impotent to either highly pathogenic avian influenza 2018 or 2020. Accordingly, it was recommended to update vaccine strain according to epidemiological condition and used the predominant circulating strain isolate in challenge test(AU)

La vacuna comercial inactivada H5 se utiliza como estrategia esencial de control de la enfermedad de la gripe aviar en Egipto. Desde los brotes iniciales de la gripe aviar altamente patógena H5N8, el virus ha variado al aparecer continuamente nuevos genotipos y variantes virales, que son los principales responsables del fracaso de la vacunación. En el presente trabajo, cuatro vacunas comerciales diferentes contra la gripe aviar se inocularon en pollos libres de patógenos específicos para evaluar su eficacia contra cepas del virus local de la gripe aviar altamente patógeno H5N8 aisladas en 2018 y 2020. Se agruparon 240 pollos pollos libres de patógenos específicos en cuatro grupos, cada uno fue inoculado con la vacuna correspondiente (60 pollos pollos libres de patógenos específicos/vacuna). Sesenta pollos SPF se mantuvieron como grupo control sin vacunar. Los sueros de los pollos vacunados recogidos en la 3ª y 4ª semana después de la vacunación se examinaron para calcular los anticuerpos neutralizantes contra la gripe aviar heteróloga H5N8 2018 y 2020. En la cuarta semana después de la vacunación, los pollos vacunados fueron retados; además, se recogieron hisopados orofaríngeos de los pollos vacunados retados para calcular la diseminación viral. Nuestros resultados revelaron que los grupos vacunados con las vacunas con códigos nº 1 y 2, que contienen dos cepas vacunales (H5N1 y H5N8) de origen local, mostraron el mayor título de inhibición de la hemaglutinación, protección (por ciento) y reducción del título de excreción viral cuando se evaluaron contra la gripe aviar altamente patógena H5N8 2018, mientras que la vacuna con código nº 3 indujo menor respuesta de anticuerpos, protección (por ciento) y reducción de la excreción viral, pero todavía dentro de un nivel satisfactorio en comparación con los grupos anteriores. Al utilizar la vacuna contra la gripe aviar altamente patógena H5N8 2020, se observó que la tasa de seronconversión, la protección (por ciento) y el título medio de reducción de la excreción viral disminuyeron en comparación con los registrados para la gripe aviar altamente patógena H5N8 2018. La vacuna con código nº 4 no fue potente para la gripe aviar altamente patógena de 2018 o de 2020. Por consiguiente, se recomendó actualizar la cepa de la vacuna de acuerdo con las condiciones epidemiológicas y utilizar el aislamiento de la cepa circulante predominante en la prueba de reto(AU)

Cellular and humoral immune status of thalassemia children with repeated blood transfusion in Yunnan province / 中国输血杂志

【Objective】 To investigate the changes in cellular immunity (peripheral blood lymphocyte subsets) and humoral immunity (serum immunoglobulin and ferritin) status among children with thalassemia who received repeated transfusions in Yunnan. 【Methods】 Forty-six children with thalassemia who underwent repeated blood transfusions from January 2020 to October 2022 were selected as the observation group. Forty children with thalassemia who did not receive blood transfusion were included in control group 1, and 46 healthy children underwent physical examination were included in control group 2. The differences in lymphocyte subsets, serum immunoglobulin levels and ferritin concentrations were compared among the three groups. 【Results】 For lymphocyte subsets: CD3+, CD4+ and CD4+/CD8+ in the observation group was lower than the control group 1 and 2: 57.60±8.36 vs 64.57±7.56 vs 66.58±5.65, 33.16±5.67 vs 38.62±8.36 vs 38.62±6.41 and 1.49±0.09 vs 2.32±0.15 vs 2.13±0.16, respectively; CD16+ CD56+ in the observation group was lower than the control group 2: 11.21±5.06 vs 16.70±7.92; CD8+ in the observation group was higher than control group 1 and control group 2: 26.63± 1.75 vs 20.60±1.43 vs 18.92±0.84; CD19+ in the observation group was higher than the control group 2: 24.06±6.42 vs 19.67 ±8.42, P<0.05, but no significant difference was noticed between the two control groups(P>0.05). For serum immunoglobulin and ferritin: IgG and ferritin in the observation group were higher than control group 1 and control group 2: 10.59±3.88 vs 7.02±3.88 vs 5.58±1.98 and 2 037.37±1 377.59 vs 72.63±56.71 vs 59.48±33.88. IgA in the observation group was higher than the control group 2: 1.06±0.92 vs 0.39±0.32(P<0.05), but no significant difference was noticed between the two control groups (P>0.05). The difference of IgM and IgE between the three groups was not significant (P > 0. 05). 【Conclusion】 The proportion of lymphocyte subsets in thalassemia children with repeated blood transfusion was imbalanced,and the level of immunoglobulin in humoral immunity was abnormal.

Immunity Status of Health Care Workers Post-Recovery from COVID-19: Natural Adaptive Immunity Persists at Nine Months Post-Infection : An Online Longitudinal Panel Survey

Background : Various studies have pinned longevity of protective Immunoglobulin-G (IgG) titres at 2-5 months. The robustness and longevity of the IgG antibody response to COVID-19 infection has been gauged in a cohort of 214 single institutional health care workers by serial quantitative immunometric tests. Currently no separate guidelines exist for vaccination of COVID-survivors and this study provides data to fill this lacuna in knowledge. Methodology : Prospective longitudinal panel survey administered to the same cohort of Health Care Workers (HCW) till such time they got vaccinated under Indian Government’s free vaccination drive for HCW. Depending upon the date of contraction of infection the HCW could be longitudinally monitored for variable periods (2-9 months). The survey questionnaire comprising multiple-choice, dichotomous, matrix and Likert-scale questions was deployed to the respondents online via email/WhatsApp. Data was expressed as box-whisker plots, trendlines and trend areas. A p-value<0.05 was considered statistically significant. The composite index of ‘Effective Immunity’ was calculated. Results : The mean IgG antibody titre was 11.13±8.6AU at 1-2m, 9.68±8.9AU at 3-4m, 8.35±5.9 AU at 6-7m and 7.87±4.4 AU at 8-9m after first symptom, respectively. The lowest titre at all time points was 0 while the highest titres were 46.8 AU, 56.5 AU, 23.4 AU and 17.4 AU at 1-2m, 3-4m, 6-7m and 8-9m, respectively. Conclusion : Adaptive active immunity acquired through natural infection may last for at least 9 months post-initial exposure and lies in the moderate protection range in 77% HCW, which can be extrapolated to vaccination and immunity passports. Separate vaccination guidelines are required for COVID-survivors. The first shot of vaccine serves as a booster second exposure/booster dose in all COVID-survivors.HCW with low IgG-titre may suffer from a false sense of security. Periodic quantitative IgG-titre based serological tests can help guide timing of second shot of vaccination and predict likelihood of re-infection

Respuesta inmune contra SARS-CoV-2 en personas con VIH convalecientes de COVID-19 / SARS-CoV-2 immunity in PWH

Desde principios de la pandemia de SARS-CoV-2 se ha debatido el curso de la enfermedad COVID-19 en personas con VIH. Por un lado, la inmunodeficiencia derivada de la infección por VIH y la mayor prevalencia de comorbilidades estarían asociadas al desarrollo de enfermedad grave. Por otro lado, la disfunción inmunológica podría evitar una respuesta inflamatoria exacerbada. En este trabajo de revisión analizamos la evidencia disponible en cuanto a la relación entre la manifestación clínica de COVID-19 y la respuesta inmune humoral y celular contra SARS-CoV-2 en el contexto de la coinfección con VIH. La bibliografía sugiere que las personas con VIH que reciben tratamiento antirretroviral logran respuestas eficaces contra SARS-CoV-2, a pesar de presentar algunas de las funciones celulares alteradas. Esto sugiere un impacto significativo de la terapia antirretroviral, no solo en el control del VIH sino en potenciar la inmunidad para restringir otras infecciones.

Since the beginning of SARS-CoV-2 pandemic, the course of COVID-19 in people with HIV has been debated. On the one hand, the immunodeficiency derived from HIV infec-tion and the higher prevalence of comorbidities would be associated with severe disease. On the other hand, due to its immunological dysfunction, an exacerbated inflam-matory response might be avoided.In this review, we analyzed the evidence regarding the clinical manifestation of COVID-19 and the humoral and cellular immune response against SARS-CoV-2 during HIV coinfection. The literature suggests that people with HIV on antiretroviral treatment achieved effective responses against SARS-CoV-2, despite having altered cell func-tions. This indicates a remarkable impact of antiretroviral therapy, not only in controlling HIV but also in boosting immunity to restrict other infections

Anticuerpos IgG determinados mediante ELISA desarrollados con antígenos de linajes Wuhan y Lambda en trabajadores de salud vacunados con BBIBP-CORV / IgG antibody response by ELISA using Wuhan and Lambda variant antigens in BBIBP-CORV vaccinated health care workers

RESUMEN Objetivos. Evaluar la respuesta de anticuerpos IgG determinada mediante ELISA utilizando antígenos de los linajes Wuhan y Lambda en trabajadores de la salud con y sin antecedente de infección por SARS-CoV-2 previa a la inmunización con la primera y segunda dosis de la vacuna Sinopharm (BBIBP-CorV). Materiales y métodos. Se realizó un estudio analítico en trabajadores de salud mayores de 18 años. Se incluyeron 51 participantes con antecedente y 100 participantes sin antecedente de infección por SARS-CoV-2, quienes recibieron dos dosis de la vacuna Sinopharm. Los anticuerpos IgG se evaluaron 21 días después de la primera dosis, 21 días después de la segunda dosis y 3 meses después de la segunda dosis mediante una prueba de ELISA in house desarrollado utilizando el antígeno completo del linaje Wuhan (B) y del linaje Lambda(C.37) del virus de SARS-CoV-2. Resultados. En ambos grupos se observó un incremento del porcentaje de personas con anticuerpos luego de la segunda dosis, sin embargo, este porcentaje disminuyó luego de 3 meses de la segunda dosis. Se halló una diferencia significativa entre el índice de anticuerpos medido por ELISA con el antígeno del linaje Wuhan versus el ELISA con el linaje Lambda (p<0,001). Conclusiones. Existe un aumento significativo de la presencia de anticuerpos tipo IgG luego de 15 días de la segunda dosis de la vacunación con BBIP-CORV en los participantes sin infección previa y una disminución, luego de 3 meses de la segunda dosis, de la razón de índices de reactividad de anticuerpos IgG en los ELISA desarrollados con el antígeno de la variante como en los ELISA desarrollados con la variante Lambda.

ABSTRACT Objectives . To evaluate the IgG antibody response by ELISA using Wuhan and Lambda antigens in health care workers with and without history of SARS-CoV-2 infection prior to immunization with the first and second doses of Sinopharm vaccine (BBIBP-CorV). Materials and methods . An analytical study was carried out in health care workers over 18 years of age. Fifty-one participants with history and 100 participants without history of SARS-CoV-2 infection, who received two doses of Sinopharm vaccine, were included. IgG antibodies were assessed 21 days after the first dose, 21 days after the second dose and 3 months after the second dose by in-house ELISA using the complete antigen of the Wuhan variant (B.1.1) and lambda variant (C-37) of SARS-CoV-2 virus. Results . Both groups showed a large increase in the percentage of people with antibodies after the second dose, however, this percentage decreased 3 months after the second dose. The difference between the antibody index measured by ELISA with Wuhan variant antigen versus the ELISA with lambda variant was significant (p<0.001). Conclusions . There is a significant increase in the presence of IgG type antibodies after 15 days of the second dose of BBIBP-CorV vaccination in participants without previous infection and a decrease after 3 months of the second dose in the ratio of IgG antibody reactivity indexes in ELISAs with the variant antigen as with ELISAs with the lambda variant.

Inmunodeficiencias humorales en pacientes adultos. Cuatro décadas de seguimiento / Antibody deficiencies in adults. Forty years of follow up

Resumen Las inmunodeficiencias humorales (IDH) comprenden un grupo de enfermedades caracterizadas por una deficiente respuesta mediada por anticuerpos. Se clasifican en primarias (IDHP), causa das por defectos propios del sistema inmune, o secundarias (IDHS) a otras enfermedades o fármacos. Nuestro objetivo fue revisar la evolución de las IDH asistidas en la Unidad Inmunología del Hospital Durand entre 1982 y 2020, dividido en dos periodos, Periodo I (1982-2009) y Periodo II (2010-2020); para evaluar el crecimiento de éstas, sus características epidemiológicas y las formas de tratamiento. Se evaluaron 205 pacientes, 176 (85.8%) IDHP y 29 (14.2%) IDHS. Las IDHP más diagnosticadas fueron: inmunodeficiencia común variable en 104 (59%) pacientes, agammaglobulinemia ligada al cromosoma X en 17 (9.6%) y deficiencia selectiva de IgA en 26 (14.8%). En 25 (14.2%) IDHP se realizó un diagnóstico molecular. Las causas de IDHS fueron: secundaria a rituximab en 21 (72.4%) pacientes, enfermedades hematológicas en tres (10.2%) y fármacos antiepilépticos en tres. Un total de 161 (78.5%) pacientes recibieron gammaglobulina, 140 (87%) IDHP y 21 (13%) IDHS; 152 (94.4%) fueron tratados con gammaglobulina endovenosa y nueve (5.6%) con gammaglobulina subcutánea. De los tratados inicialmente con forma endovenosa, 30 (19.7%) cambiaron a subcutánea. El crecimiento en la can tidad de pacientes entre ambos periodos del estudio fue mayor al 250%, y al 700% en pacientes incorporados por año. El crecimiento de las IDHS con relación al de las IDHP fue más del doble. Al finalizar el estudio 125 pacientes continuaban en seguimiento, 80% IDHP y 20% IDHS, y 14 fallecieron.

Abstract Antibody deficiencies (AD) are characterized by low or absent immunoglobulin levels or the inability to develop a specific antibody response. They are classified in primary (PAD) when there is an intrinsic immune defect, or secondary (SAD) to other dis eases or drugs. The aim of our study was to review the evolutio n of AD assisted at the Immunology Unit, Hospital Durand between 1982 and 2020, divided into two periods: Period I (1982-2009) and Period II (2010-2020); to evaluate their growth, epidemiologic features and treatment options. A total of 205 patients were identified, 176 (85.8%) with PAD and 29 (14.2%) with SAD. The most frequent PAD were common variable immunodeficiency in 104 (59%) patients, X linked agammaglobulinemia in 17 (9.6%) and selective IgA deficiency in 26 (14.8%). Genetic defects were found in 25 (14.2%) patients with PAD. SAD cases were associated with rituximab in 21 (72.4%) subjects, haematological disease in three (10.2%) and with antiepileptic drugs in other three; 161 (78.5%) patients were treated with immunoglobulins, 140 (87%) PAD y 21 (13%) SAD; 152 (94.4%) received intravenous immunoglobulins and nine (5.6%) subcutaneous immunoglobulins. Thirty (19.7%) patients treated at first with intravenous immunoglobulins changed to subcutaneous formulations. The increase in number of patients between both periods was greater than 250%, and more than 700% in patients added per year. SAD growth was greater than twice times comparing with PAD. By the end of the study 125 patients continued in follow up, 80% PAD y 20% SAD and 14 died.

Evaluación de ensayos ultramicroanalíticos para la detección de anticuerpos contra el SARS-CoV-2 / Evaluation of ultramicroanalytic assays to detect antibodies against SARS-CoV-2

Introducción: En el presente trabajo se muestran los resultados de la validación de los ensayos serológicos in vitro para la detección de anticuerpos IgM, IgG y anticuerpos totales contra el SARS-CoV-2 UMELISA SARS-CoV-2 IgM, UMELISA ANTI-SARS-CoV-2 y UMELISA SARS-CoV-2 IgG desarrollados por el Centro de Inmunoensayo (CIE). Métodos: Se utilizaron paneles de muestras de suero de individuos negativos y de casos confirmados de COVID-19 para determinar el desempeño analítico de cada ensayo. Resultados: La especificidad clínica de los ensayos UMELISA SARS-CoV-2 IgM, UMELISA ANTI-SARS-CoV-2 y UMELISA SARS-CoV-2 IgG fue del 100 por ciento en todos los ensayos y la especificidad analítica fue de 100 por ciento para los dos primeros ensayos y del 93,1 por cientopara el último. La sensibilidad clínica fue de 64,3, 80,8 y 97,5 por ciento, respectivamente. El valor predictivo positivo fue de 100 por ciento en todos los ensayos, en tanto que el negativo osciló entre 83,3 y 95,2 por ciento. La concordancia fluctuó entre 92,4 y 96,9 por ciento y el índice kappa de todos los ensayos fue muy bueno. La sensibilidad de los ensayos se incrementó a 82,76, 96,5 y 100 por ciento, respectivamente, en las muestras de suero colectadas con más de 14 días de iniciado el cuadro clínico. Conclusiones: Los ensayos demostraron una elevada sensibilidad y especificidad, lo que permite contar con herramientas basadas en una tecnología desarrollada en Cuba que posibilita la realización de estudios serológicos, vigilancia epidemiológica y de otro tipo, incluyendo los relacionados con vacunas en una plataforma con amplia distribución nacional(AU)

Introduction: This paper shows the results obtained in the validation of in vitro serological assays to detect IgM, IgG antibodies, and total antibodies against SARS-CoV-2 UMELISA SARS-CoV-2 IgM, UMELISA ANTI-SARS-CoV-2 and UMELISA SARS-CoV-2 IgG developed by the Immunoassay Center. Methods: Panels of serum samples from negative and COVID-19 confirmed patients were used to determine the analytical performance of each assay. Results: UMELISA SARS-CoV-2 IgM, UMELISA ANTI-SARS-CoV-2 and UMELISA SARS-CoV-2 IgG assays demonstrated 100 percent clinical specificity for all assays; and 100 percent analytical specificity for the first two assays, and 93.1 percent for the last one. Clinical sensitivity was 64.3 percent, 80.8 percent and 97.5 percent, respectively. The positive predictive value was 100 percent in all assays, while the negative predictive value ranged from 83.3 percent to 95.2 percent. Concordance varied from 92.4 percent to 96.9 percent, and kappa index in every assay was very good. Assays sensitivity increased to 82.7 percent, 96.5 percent and 100 percent, respectively for serum samples collected more than 14 days after onset of the symptoms. Conclusions: The assays demonstrated high sensitivity and specificity, which allows us to have Cuban technology-based tools for serological, epidemiological surveillance, and other types of studies, including those related to vaccines on a platform with wide national distribution(AU)

Desarrollo de inmunidad humoral en personas infectadas por SARS-COV-2 / Development of humoral immunity in SARS-COV-2-infected individuals

Objetivo: Analizar el desarrollo de inmunidad humoral en personas infectadas por SARS-COV-2 de las ciudades Quito y Ambato del Ecuador. Método: Estudio observacional de pacientes reales diagnosticados con Covid-19, se tabularon un total de 31 pacientes sometidos a pruebas nasofaríngeas. Resultados: El hallazgo de que una prueba de anticuerpos que da positivo sugiere que el riesgo de reinfección sea subjetivamente bajo; no obstante, los individuos que se recuperan de una infección por el SARS-CoV-2 todavía poseen restos de material del virus es decir ácido ribonucleico o ARN en el cuerpo humano por lo menos 3 meses. Conclusión: Las personas estudiadas generan cierta inmunidad humoral; las primeras respuestas humorales específicas del SARS-CoV-2 estuvieron dominadas por anticuerpos IgM, a medida que la infección progresa hasta el término de los síntomas; sin embargo; se necesitan de varios estudios para demostrar que las personas infectadas por el coronavirus Covid-19, tengan anticuerpos neutralizantes Anti-Spike.

Objective: To analyze the development of humoral immunity in people infected by SARS-COV-2 in the cities of Quito and Ambato, Ecuador. Methods: Observational study of real patients diagnosed with Covid-19, a total of 31 patients submitted to nasopharyngeal tests were tabulated. Results: The finding of a positive antibody test suggests that the risk of reinfection is subjectively low; however, individuals who recover from SARS-CoV-2 infection still possess remnants of virus material i.e. ribonucleic acid or RNA in the human body for at least 3 months. Conclusion: The studied individuals generate some humoral immunity; early SARS-CoV-2 specific humoral responses were dominated by IgM antibodies, as the infection progresses to the termination of symptoms; however; several studies are needed to demonstrate that persons infected with Covid-19 coronavirus, have neutralizing Anti-Spike antibodies.

A trimeric RBD protein as a booster vaccine enhanced the humoral response and broad neutralization against SARS-CoV-2 in mice / 中华微生物学和免疫学杂志

Objective:To investigate the efficacy of a SARS-CoV-2 recombinant protein vaccine as a booster dose.Methods:A new immunogen, namely RBD-sc-trimer, was designed by tandem repeating of single receptor binding domain (RBD) of SARS-CoV-2 spike (S) protein to mimic the trimeric form of RBD presented by the virus. The RBD-sc-trimer protein was expressed as a His-tagged fusion protein using a baculovirus expression system and purified by nickel affinity column. The purified protein was identified by Western blot. Its in vitro binding activity to human angiotensin converting enzyme 2 (hACE2) was analyzed by ELISA. The immunogenicity of RBD-sc-trimer as well as RBD proteins of other forms including RBD dimer (RBD-Fc), RBD monomer (RBD) and S protein trimer (S trimer) as a booster dose was evaluated in BALB/c mice. Results:In terms of both binding and neutralizing antibodies against SARS-CoV-2, RBD-sc-trimer showed an immunogenicity that was superior to that of RBD-Fc and RBD and close to the level of S trimer. The antibody response induced by RBD-sc-trimer was characterized as Th1-biased. Moreover, it displayed a stronger cross-neutralization activity against SARS-CoV-2 Beta, Delta and Omicron variants. The titer of neutralizing antibody against Omicron induced by RBD-sc-trimer only decreased by 9.1 folds relative to the prototype strain, while the antibody response induced by RBD-Fc and S trimer decreased by 68.4 and 70.8 folds, respectively.Conclusions:The recombinant protein, RBD-sc-trimer, which was capable of eliciting stronger humoral response in mice as a booster dose and showed the superiority in raising cross-reactive antibodies against SARS-CoV-2 variants over non-trimeric RBD forms, should be considered as an optimal immunogen for the development of more effective SARS-CoV-2 vaccines.

Construction of a novel bivalent DNA vaccine against SARS-CoV-2 and influenza A virus H3N2 and evaluation of its immunogenicity in mice / 中华微生物学和免疫学杂志

Objective:To construct a bivalent DNA vaccine against SARS-CoV-2 and influenza A virus H3N2 and to evaluate its immunogenicity in mice.Methods:The coding sequences for spike 1 (S1) protein of SARS-CoV-2 Beta variant and hemagglutinin (HA) of influenza A virus Cambodia (H3N2) strain were codon-optimized and synthesized. The two coding genes were ligated by the self-cleaving 2A peptide using over-lapping PCR to construct S1-2A-HA fragment, which was inserted into pVRC vector to construct the bivalent DNA vaccine, named as pVRC-S1-2A-HA. Indirect immunofluorescence assay (IFA) and Western blot were performed to detect the expression of S1 and HA proteins. BALB/c mice were immunized with pVRC-S1-2A-HA by intramuscular injection and electroporation. The humoral immune responses induced in mice were detected by indirect ELISA, pseudovirus neutralization assay and hemagglutination inhibition assay. Cellular immune responses were detected by IFN-γ ELISPOT, intracellular cytokine staining (ICS) and cytometric bead array (CBA).Results:The bivalent DNA vaccine pVRC-S1-2A-HA could express S1 and HA proteins in vitro. Specific cellular immune responses against S1 protein and specific IgG antibody against HA protein were significantly induced in mice with single-dose immunization. The antigen-specific immunity was significantly enhanced after booster immunization. The geometric mean titer (GMT) of specific IgG antibody increased to 3 251 for S1 protein and 45 407 for HA protein after two-dose immunization. Moreover, the S1-specific T cells increased to 1 238 SFC/10 6 cells. ICS results indicated that the booster vaccination induced CD4 + T and CD8 + T cells to produce IL-2, IFN-γ and TNF-α in mice. The secretion of various cytokines including IL-2, IL- 4, IL-6, IL-10 and IFN-γ in mouse splenocytes was induced after single-dose immunization. Conclusions:A bivalent DNA vaccine against SARS-CoV-2 and influenza A virus H3N2 was constructed and could induce S1- and HA-specific humoral and cellular immune responses in mice, suggesting the great potential of it for further development and application.

Correlation between post-transplant non-HLA antibodies and humoral rejection after kidney transplantation / 中华器官移植杂志

Objective:To explore the correlation between post-transplant non-HLA antibodies and humoral rejection(HR)after kidney transplantation(KT).Methods:A retrospective study was conducted for KT recipients with non-HLA antibody level detected from September 2019 to January 2021.The recipients with biopsy confirmed HR and donor-specific HLA antibodies negative or feeble positive at the time of HR were designated as HR group while recipients with stable renal allograft function from 2 weeks post-KT to the time of detecting non-HLA antibody as stable group.The levels of HLA antibody, MHC classⅠchain-related gene A(MICA)antibody and 32 non-HLA antibodies were tested by Luminex single antigen bead and the levels of angiotensin Ⅱ type 1 receptor(AT1R)antibody quantified by enzyme-linked immunosorbent assay (ELISA). Inter-group differences in positive rate of non-HLA antibodies and number of positive non-HLA antibodies were analyzed.Results:Twenty-four recipients had positive non-HLA antibodies while the remainders had no positive non-HLA antibodies.Three HR recipients were positive for actin antibody, collagen Ⅲ antibody, glutathione S-transferase theta-1 antibody or IFN-γ antibody respectively.However, all four non-HLA antibodies of stable recipients were negative.There was significant inter-group difference( P=0.017). Four HR recipients were positive for collagenⅡantibody while only 1 stable recipient was positive for collagenⅡantibody.The positive rate of collagenⅡ antibody was significantly higher in HR recipients than that in stable recipients( P=0.023). HR recipients had an average of 2.36 positive non-HLA antibodies while stable recipients had an average of 0.90.There was significant inter-group difference ( P=0.008). Conclusions:A high level of non-HLA antibodies may elevate the risk of HR after KT.

Coagulopathy and the humoral response against viral proteins in patients at different stages of COVID-19

BACKGROUND Patients with severe coronavirus disease 2019 (COVID-19) often present with coagulopathies and have high titres of circulating antibodies against viral proteins. OBJECTIVES Herein, we evaluated the association between D-dimer and circulating immunoglobulin levels against viral proteins in patients at different clinical stages of COVID-19. METHODS For this, we performed a cross-sectional study involving patients of the first wave of COVID-19 clinically classified as oligosymptomatic (n = 22), severe (n = 30), cured (n = 27) and non-infected (n = 9). Next, we measured in the plasma samples the total and fraction of immunoglobulins against the nucleoprotein (NP) and the receptor-binding domain (RBD) of the spike proteins by enzyme-linked immunosorbent assay (ELISA) assays. FINDINGS Patients with severe disease had a coagulation disorder with high levels of D-dimer as well as circulating IgG against the NP but not the RBD compared to other groups of patients. In addition, high levels of D-dimer and IgG against the NP and RBD were associated with disease severity among the patients in this study. MAIN CONCLUSIONS Our data suggest that IgG against NP and RBD participates in the worsening of COVID-19. Although the humoral response against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is partially understood, and more efforts are needed to clarify gaps in the knowledge of this process.

Evaluation and follow-up of antibody formation after CoronaVac vaccine

SUMMARY OBJECTIVE: The aim of this study was to monitor the time-dependent change by evaluating the antibody levels at the 4th, 7th, 10th, 13th, and 16th weeks after the second dose of the CoronaVac vaccine. METHODS: The study group (n=65) were between 21 and 60 years old and received two doses of the CoronaVac vaccine. Blood samples were collected after 4th, 7th, 10th, 13th, and 16th weeks of the second dose of the vaccine administration. There was a coronavirus disease 2019 recovered group (n=29) who were SARS-CoV-2 real-time PCR test result positive before the vaccination period, and no coronavirus disease 2019 history group (n=36). Age, BMI, gender, smoking, comorbidity, coronavirus disease 2019 contact history, and working in the coronavirus disease 2019 service history of the individuals were recorded. RESULTS: No statistically significant difference was found in the descriptive findings of the individuals according to coronavirus disease 2019 recovered group and no coronavirus disease 2019 history group. It was observed that antibody levels in the coronavirus disease 2019 recovered group were found to be higher for each period of serum collection compared to the no coronavirus disease 2019 history group, which were statistically significant. The distribution curves of the antibody levels according to the timing of blood collection in coronavirus disease 2019 recovered group, no coronavirus disease 2019 history group, and total subjects were extrapolated, and it was observed that the estimated time for the antibodies to reach the threshold value of the test was 214, 145, and 166 days after vaccination. CONCLUSION: It is important to make booster doses, as the CoronaVac vaccine will lose its effect after the fifth month due to the decrease in Ab levels. In addition, since the antibody levels decrease later in those who have a history of coronavirus disease 2019 infection and are vaccinated, individuals who have no previous history of coronavirus disease 2019 should be given priority for vaccination.

Anti-SARS-CoV-2 antibody immunoreactivity profiles during COVID-19 recurrence

ABSTRACT Background: This study aimed to evaluate IgG and IgM levels in COVID-19 recurrence. Methods: The serum antibody levels and clinical data from 73 healthcare workers with SARS-CoV-2 divided into seroconverted (n=51) and non-seroconverted (n=22) groups were assessed. The presence of specific anti-nucleocapsid (anti-N) IgM and IgG for SARS-CoV-2 was evaluated. IgG antibodies to the SARS-CoV-2 spike receptor-binding domain were used to confirm non-seroconversion in all negative anti-N. Results: Four recurrent cases displayed mild symptoms and were non-seroconverted until the recurrence of symptoms. Conclusions: Undetectable anti-nucleocapsid IgM and IgG levels may be correlated with symptomatic COVID-19 recurrence.