RESUMEN
Many infections, including malaria, are associated with an increase in autoantibodies (AAbs). Prior studies have reported an association between genetic markers of susceptibility to autoimmune disease and resistance to malaria, but the underlying mechanisms are unclear. Here, we performed a longitudinal study of children and adults (n = 602) in Mali and found that high levels of plasma AAbs before the malaria season independently predicted a reduced risk of clinical malaria in children during the ensuing malaria season. Baseline AAb seroprevalence increased with age and asymptomatic Plasmodium falciparum infection. We found that AAbs purified from the plasma of protected individuals inhibit the growth of blood-stage parasites and bind P. falciparum proteins that mediate parasite invasion. Protected individuals had higher plasma immunoglobulin G (IgG) reactivity against 33 of the 123 antigens assessed in an autoantigen microarray. This study provides evidence in support of the hypothesis that a propensity toward autoimmunity offers a survival advantage against malaria.
Asunto(s)
Autoanticuerpos , Inmunoglobulina G , Malaria Falciparum , Plasmodium falciparum , Humanos , Plasmodium falciparum/inmunología , Autoanticuerpos/inmunología , Malaria Falciparum/inmunología , Malaria Falciparum/parasitología , Niño , Preescolar , Adulto , Inmunoglobulina G/inmunología , Inmunoglobulina G/sangre , Femenino , Malí , Masculino , Adolescente , Anticuerpos Antiprotozoarios/inmunología , Estudios Longitudinales , Lactante , Antígenos de Protozoos/inmunología , Adulto Joven , Autoantígenos/inmunología , Estudios Seroepidemiológicos , Persona de Mediana EdadRESUMEN
Human immune responses to viral infections are highly variable, but the genetic factors that contribute to this variability are not well characterized. We used VirScan, a high-throughput epitope scanning technology, to analyze pan-viral antibody reactivity profiles of twins and SNP-genotyped individuals. Using these data, we determined the heritability and genomic loci associated with antibody epitope selection, response breadth, and control of Epstein-Barr virus (EBV) viral load. 107 EBV peptide reactivities were heritable and at least two Epstein-Barr nuclear antigen 2 (EBNA-2) reactivities were associated with variants in the MHC class II locus. We identified an EBV serosignature that predicted viral load in peripheral blood mononuclear cells and was associated with variants in the MHC class I locus. Our study illustrates the utility of epitope profiling to investigate the genetics of pathogen immunity, reports heritable features of the antibody response to viruses, and identifies specific HLA loci important for EBV epitope selection.
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Anticuerpos Antivirales/metabolismo , Epítopos/metabolismo , Infecciones por Virus de Epstein-Barr/genética , Antígenos Nucleares del Virus de Epstein-Barr/metabolismo , Genotipo , Herpesvirus Humano 4/fisiología , Epítopos Inmunodominantes/metabolismo , Proteínas Virales/metabolismo , Adolescente , Adulto , Anciano , Estudios de Cohortes , Mapeo Epitopo , Epítopos/genética , Infecciones por Virus de Epstein-Barr/inmunología , Antígenos Nucleares del Virus de Epstein-Barr/genética , Femenino , Antígenos HLA/genética , Antígenos HLA/metabolismo , Humanos , Inmunidad Humoral , Epítopos Inmunodominantes/genética , Masculino , Persona de Mediana Edad , Péptidos/genética , Polimorfismo de Nucleótido Simple , Carácter Cuantitativo Heredable , Estudios Seroepidemiológicos , Carga Viral , Proteínas Virales/genética , Adulto JovenRESUMEN
The development, validation, and appropriate application of serological assays to detect antibodies to SARS-CoV-2 are essential to determining seroprevalence of this virus in the United States and globally and in guiding government leadership and the private sector on back-to-work policies. An interagency working group of the US Department of Health and Human Services convened a virtual workshop to identify knowledge gaps and key outstanding scientific issues and to develop strategies to fill them. Key outcomes of the workshop included recommendations for (1) advancing serology assays as a tool to better understand SARS-CoV-2 infection and (2) conducting crucial serology field studies to advance an understanding of immunity to SARS-CoV-2, leading to protection and duration of protection, including the correlation between serological test results and risk of reinfection.
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Anticuerpos Antivirales/sangre , Betacoronavirus/inmunología , Infecciones por Coronavirus/inmunología , Neumonía Viral/inmunología , Estudios Seroepidemiológicos , Pruebas Serológicas/métodos , COVID-19 , Infecciones por Coronavirus/sangre , Humanos , Pandemias , Neumonía Viral/sangre , SARS-CoV-2RESUMEN
We conducted a serological study to define correlates of immunity against SARS-CoV-2. Compared to those with mild coronavirus disease 2019 (COVID-19) cases, individuals with severe disease exhibited elevated virus-neutralizing titers and antibodies against the nucleocapsid (N) and the receptor binding domain (RBD) of the spike protein. Age and sex played lesser roles. All cases, including asymptomatic individuals, seroconverted by 2 weeks after PCR confirmation. Spike RBD and S2 and neutralizing antibodies remained detectable through 5-7 months after onset, whereas α-N titers diminished. Testing 5,882 members of the local community revealed only 1 sample with seroreactivity to both RBD and S2 that lacked neutralizing antibodies. This fidelity could not be achieved with either RBD or S2 alone. Thus, inclusion of multiple independent assays improved the accuracy of antibody tests in low-seroprevalence communities and revealed differences in antibody kinetics depending on the antigen. We conclude that neutralizing antibodies are stably produced for at least 5-7 months after SARS-CoV-2 infection.
Asunto(s)
Betacoronavirus/inmunología , Técnicas de Laboratorio Clínico/métodos , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/inmunología , Inmunidad Humoral , Neumonía Viral/epidemiología , Neumonía Viral/inmunología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Arizona/epidemiología , Betacoronavirus/aislamiento & purificación , COVID-19 , Prueba de COVID-19 , Infecciones por Coronavirus/sangre , Infecciones por Coronavirus/diagnóstico , Proteínas de la Nucleocápside de Coronavirus , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proteínas de la Nucleocápside/inmunología , Pandemias , Fosfoproteínas , Neumonía Viral/sangre , Neumonía Viral/diagnóstico , Prevalencia , Dominios y Motivos de Interacción de Proteínas , SARS-CoV-2 , Estudios Seroepidemiológicos , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/inmunología , Adulto JovenRESUMEN
During their blood-feeding process, ticks are known to transmit various viruses to vertebrates, including humans. Recent viral metagenomic analyses using next-generation sequencing (NGS) have revealed that blood-feeding arthropods like ticks harbor a large diversity of viruses. However, many of these viruses have not been isolated or cultured, and their basic characteristics remain unknown. This study aimed to present the identification of a difficult-to-culture virus in ticks using NGS and to understand its epidemic dynamics using molecular biology techniques. During routine tick-borne virus surveillance in Japan, an unknown flaviviral sequence was detected via virome analysis of host-questing ticks. Similar viral sequences have been detected in the sera of sika deer and wild boars in Japan, and this virus was tentatively named the Saruyama virus (SAYAV). Because SAYAV did not propagate in any cultured cells tested, single-round infectious virus particles (SRIP) were generated based on its structural protein gene sequence utilizing a yellow fever virus-based replicon system to understand its nationwide endemic status. Seroepidemiological studies using SRIP as antigens have demonstrated the presence of neutralizing antibodies against SAYAV in sika deer and wild boar captured at several locations in Japan, suggesting that SAYAV is endemic throughout Japan. Phylogenetic analyses have revealed that SAYAV forms a sister clade with the Orthoflavivirus genus, which includes important mosquito- and tick-borne pathogenic viruses. This shows that SAYAV evolved into a lineage independent of the known orthoflaviviruses. This study demonstrates a unique approach for understanding the epidemiology of uncultured viruses by combining viral metagenomics and pseudoinfectious viral particles.
Asunto(s)
Ciervos , Flavivirus , Metagenómica , Garrapatas , Animales , Metagenómica/métodos , Japón/epidemiología , Ciervos/virología , Flavivirus/genética , Flavivirus/aislamiento & purificación , Flavivirus/clasificación , Garrapatas/virología , Filogenia , Viroma/genética , Virión/genética , Sus scrofa/virología , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Estudios Seroepidemiológicos , Genoma ViralRESUMEN
The World Health Organization identifies a strong surveillance system for malaria and its mosquito vector as an essential pillar of the malaria elimination agenda. Anopheles salivary antibodies are emerging biomarkers of exposure to mosquito bites that potentially overcome sensitivity and logistical constraints of traditional entomological surveys. Using samples collected by a village health volunteer network in 104 villages in Southeast Myanmar during routine surveillance, the present study employs a Bayesian geostatistical modeling framework, incorporating climatic and environmental variables together with Anopheles salivary antigen serology, to generate spatially continuous predictive maps of Anopheles biting exposure. Our maps quantify fine-scale spatial and temporal heterogeneity in Anopheles salivary antibody seroprevalence (ranging from 9 to 99%) that serves as a proxy of exposure to Anopheles bites and advances current static maps of only Anopheles occurrence. We also developed an innovative framework to perform surveillance of malaria transmission. By incorporating antibodies against the vector and the transmissible form of malaria (sporozoite) in a joint Bayesian geostatistical model, we predict several foci of ongoing transmission. In our study, we demonstrate that antibodies specific for Anopheles salivary and sporozoite antigens are a logistically feasible metric with which to quantify and characterize heterogeneity in exposure to vector bites and malaria transmission. These approaches could readily be scaled up into existing village health volunteer surveillance networks to identify foci of residual malaria transmission, which could be targeted with supplementary interventions to accelerate progress toward elimination.
Asunto(s)
Anopheles , Teorema de Bayes , Malaria , Mosquitos Vectores , Animales , Anopheles/parasitología , Mosquitos Vectores/parasitología , Humanos , Malaria/transmisión , Malaria/epidemiología , Malaria/inmunología , Malaria/parasitología , Estudios Seroepidemiológicos , Mordeduras y Picaduras de Insectos/epidemiología , Mordeduras y Picaduras de Insectos/inmunología , Mordeduras y Picaduras de Insectos/parasitología , Esporozoítos/inmunologíaRESUMEN
BACKGROUND: Natural history studies have correlated serotype-specific anti-capsular polysaccharide (CPS) IgG in newborns with a reduced risk of group B streptococcal disease. A hexavalent CPS-cross-reactive material 197 glycoconjugate vaccine (GBS6) is being developed as a maternal vaccine to prevent invasive group B streptococcus in young infants. METHODS: In an ongoing phase 2, placebo-controlled trial involving pregnant women, we assessed the safety and immunogenicity of a single dose of various GBS6 formulations and analyzed maternally transferred anti-CPS antibodies. In a parallel seroepidemiologic study that was conducted in the same population, we assessed serotype-specific anti-CPS IgG concentrations that were associated with a reduced risk of invasive disease among newborns through 89 days of age to define putative protective thresholds. RESULTS: Naturally acquired anti-CPS IgG concentrations were associated with a reduced risk of disease among infants in the seroepidemiologic study. IgG thresholds that were determined to be associated with 75 to 95% reductions in the risk of disease were 0.184 to 0.827 µg per milliliter. No GBS6-associated safety signals were observed among the mothers or infants. The incidence of adverse events and of serious adverse events were similar across the trial groups for both mothers and infants; more local reactions were observed in the groups that received GBS6 containing aluminum phosphate. Among the infants, the most common serious adverse events were minor congenital anomalies (umbilical hernia and congenital dermal melanocytosis). GBS6 induced maternal antibody responses to all serotypes, with maternal-to-infant antibody ratios of approximately 0.4 to 1.3, depending on the dose. The percentage of infants with anti-CPS IgG concentrations above 0.184 µg per milliliter varied according to serotype and formulation, with 57 to 97% of the infants having a seroresponse to the most immunogenic formulation. CONCLUSIONS: GBS6 elicited anti-CPS antibodies against group B streptococcus in pregnant women that were transferred to infants at levels associated with a reduced risk of invasive group B streptococcal disease. (Funded by Pfizer and the Bill and Melinda Gates Foundation; C1091002 ClinicalTrials.gov number, NCT03765073.).
Asunto(s)
Infecciones Estreptocócicas , Vacunas Estreptocócicas , Streptococcus agalactiae , Femenino , Humanos , Lactante , Recién Nacido , Embarazo , Anticuerpos Antibacterianos , Inmunoglobulina G , Estudios Seroepidemiológicos , Infecciones Estreptocócicas/epidemiología , Infecciones Estreptocócicas/inmunología , Infecciones Estreptocócicas/prevención & control , Vacunas Combinadas/administración & dosificación , Vacunas Combinadas/efectos adversos , Vacunas Combinadas/inmunología , Vacunas Combinadas/uso terapéutico , Vacunas Conjugadas/administración & dosificación , Vacunas Conjugadas/efectos adversos , Vacunas Conjugadas/inmunología , Vacunas Conjugadas/uso terapéutico , Vacunas Estreptocócicas/administración & dosificación , Vacunas Estreptocócicas/efectos adversos , Vacunas Estreptocócicas/inmunología , Vacunas Estreptocócicas/uso terapéutico , Inmunidad Materno-Adquirida/inmunologíaRESUMEN
Socio-economic disparities were associated with disproportionate viral incidence between neighborhoods of New York City (NYC) during the first wave of SARS-CoV-2. We investigated how these disparities affected the co-circulation of SARS-CoV-2 variants during the second wave in NYC. We tested for correlation between the prevalence, in late 2020/early 2021, of Alpha, Iota, Iota with E484K mutation (Iota-E484K), and B.1-like genomes and pre-existing immunity (seropositivity) in NYC neighborhoods. In the context of varying seroprevalence we described socio-economic profiles of neighborhoods and performed migration and lineage persistence analyses using a Bayesian phylogeographical framework. Seropositivity was greater in areas with high poverty and a larger proportion of Black and Hispanic or Latino residents. Seropositivity was positively correlated with the proportion of Iota-E484K and Iota genomes, and negatively correlated with the proportion of Alpha and B.1-like genomes. The proportion of persisting Alpha lineages declined over time in locations with high seroprevalence, whereas the proportion of persisting Iota-E484K lineages remained the same in high seroprevalence areas. During the second wave, the geographic variation of standing immunity, due to disproportionate disease burden during the first wave of SARS-CoV-2 in NYC, allowed for the immune evasive Iota-E484K variant, but not the more transmissible Alpha variant, to circulate in locations with high pre-existing immunity.
Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , Ciudad de Nueva York/epidemiología , SARS-CoV-2/inmunología , SARS-CoV-2/genética , COVID-19/epidemiología , COVID-19/virología , Estudios Seroepidemiológicos , Factores Socioeconómicos , Masculino , Femenino , Adulto , Persona de Mediana Edad , MutaciónRESUMEN
BACKGROUND: The B.1.1.529 (omicron) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first identified on November 25, 2021, in Gauteng province, South Africa. Data regarding the seroprevalence of SARS-CoV-2 IgG in Gauteng before the fourth wave of coronavirus disease 2019 (Covid-19), in which the omicron variant was dominant, are needed. METHODS: We conducted a seroepidemiologic survey from October 22 to December 9, 2021, in Gauteng to determine the seroprevalence of SARS-CoV-2 IgG. Households included in a previous seroepidemiologic survey (conducted from November 2020 to January 2021) were contacted; to account for changes in the survey population, there was a 10% increase in the households contacted, with the use of the same sampling framework. Dried-blood-spot samples were tested for IgG against SARS-CoV-2 spike protein and nucleocapsid protein with the use of quantitative assays. We also evaluated Covid-19 epidemiologic trends in Gauteng, including cases, hospitalizations, recorded deaths, and excess deaths from the start of the pandemic through January 12, 2022. RESULTS: Samples were obtained from 7010 participants, of whom 1319 (18.8%) had received a Covid-19 vaccine. The seroprevalence of SARS-CoV-2 IgG ranged from 56.2% (95% confidence interval [CI], 52.6 to 59.7) among children younger than 12 years of age to 79.7% (95% CI, 77.6 to 81.5) among adults older than 50 years of age. Vaccinated participants were more likely to be seropositive for SARS-CoV-2 than unvaccinated participants (93.1% vs. 68.4%). Epidemiologic data showed that the incidence of SARS-CoV-2 infection increased and subsequently declined more rapidly during the fourth wave than it had during the three previous waves. The incidence of infection was decoupled from the incidences of hospitalization, recorded death, and excess death during the fourth wave, as compared with the proportions seen during previous waves. CONCLUSIONS: Widespread underlying SARS-CoV-2 seropositivity was observed in Gauteng before the omicron-dominant wave of Covid-19. Epidemiologic data showed a decoupling of hospitalizations and deaths from infections while omicron was circulating. (Funded by the Bill and Melinda Gates Foundation.).
Asunto(s)
COVID-19 , SARS-CoV-2 , Adolescente , Adulto , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/inmunología , COVID-19/sangre , COVID-19/epidemiología , COVID-19/inmunología , COVID-19/virología , Vacunas contra la COVID-19 , Niño , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Persona de Mediana Edad , Vigilancia en Salud Pública , SARS-CoV-2/genética , SARS-CoV-2/inmunología , SARS-CoV-2/patogenicidad , Estudios Seroepidemiológicos , Sudáfrica/epidemiología , Glicoproteína de la Espiga del Coronavirus/inmunología , Adulto JovenRESUMEN
Identifying the potential for SARS-CoV-2 reinfection is crucial for understanding possible long-term epidemic dynamics. We analysed longitudinal PCR and serological testing data from a prospective cohort of 4,411 United States employees in 4 states between April 2020 and February 2021. We conducted a multivariable logistic regression investigating the association between baseline serological status and subsequent PCR test result in order to calculate an odds ratio for reinfection. We estimated an odds ratio for reinfection ranging from 0.14 (95% CI: 0.019 to 0.63) to 0.28 (95% CI: 0.05 to 1.1), implying that the presence of SARS-CoV-2 antibodies at baseline is associated with around 72% to 86% reduced odds of a subsequent PCR positive test based on our point estimates. This suggests that primary infection with SARS-CoV-2 provides protection against reinfection in the majority of individuals, at least over a 6-month time period. We also highlight 2 major sources of bias and uncertainty to be considered when estimating the relative risk of reinfection, confounders and the choice of baseline time point, and show how to account for both in reinfection analysis.
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Anticuerpos Antivirales/sangre , COVID-19/inmunología , Reinfección/inmunología , Adolescente , Adulto , Anciano , COVID-19/epidemiología , COVID-19/prevención & control , Prueba de Ácido Nucleico para COVID-19 , Prueba Serológica para COVID-19 , Humanos , Modelos Logísticos , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Estudios Prospectivos , Reinfección/prevención & control , SARS-CoV-2/inmunología , Estudios Seroepidemiológicos , Factores de Tiempo , Estados Unidos/epidemiología , Lugar de Trabajo/estadística & datos numéricos , Adulto JovenRESUMEN
This review aims to gather and disseminate updated information regarding hepatitis A virus (HAV) in Latin America (LA) in the last 11 years, including seroprevalence, post-vaccination studies, virus detection in aqueous matrices and food samples, and outbreak reports. Only 24 seroprevalence studies were published between 2012 and 2023 with 55%-100% reported prevalences of anti-HAV IgG. Among the 25 LA countries, only eight of them have introduced HAV vaccines into their immunisation programs. Outbreaks of hepatitis A occurred between 2017-2019, mainly affecting men who have sex with men in Argentina, Brazil and Chile, probably as a consequence of the abrupt decline of young adults' immunity. This could be due to that young adult have never been infected in childhood (due to socio-health improvements) and are above the cut-off ages to be included when the vaccination programs were introduced. Although scarce, studies focused on environmental and food HAV surveillance have shown viral presence in these samples. Surface waters presented HAV detections between 1.2% and 86.7%, and untreated wastewaters between 2.8% and 70.9%. Genotypes found in all cases were IA and IC. The only wastewater-based epidemiology study showed to be a useful tool as a complement of traditional epidemiological surveillance. Only four LA countries have looked for HAV in food samples, with genome detection rates between 9% and 33%. Latin American HAV circulation scenario is changing. In countries where socioeconomic and sanitary conditions have not improved, the virus persists with high endemicity and the access to the vaccine should be re-evaluated by local governments. In countries where access to clean water, better sanitary conditions and HAV immunisation programs have been implemented, the number of cases among young adults seems to be increasing, alerting health authorities.
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Vacunas contra la Hepatitis A , Virus de la Hepatitis A , Hepatitis A , Hepatitis A/epidemiología , Hepatitis A/virología , Hepatitis A/prevención & control , Humanos , América Latina/epidemiología , Estudios Seroepidemiológicos , Virus de la Hepatitis A/inmunología , Virus de la Hepatitis A/genética , Virus de la Hepatitis A/aislamiento & purificación , Vacunas contra la Hepatitis A/administración & dosificación , Vacunas contra la Hepatitis A/inmunología , Brotes de Enfermedades , Anticuerpos de Hepatitis A/sangre , GenotipoRESUMEN
Influenza in dogs holds considerable public health significance due to their close companionship with humans, yet several facets of this phenomenon remain largely unexplored. This study undertook a systematic review and meta-analysis of observational studies to gauge the global seroprevalence of influenza in dogs. We also assessed whether pet dogs exhibited a higher seroprevalence of influenza compared to non-pet dogs, explored seasonal variations in seroprevalence, scrutinised the design and reporting standards of existing studies, and elucidated the geographical distribution of canine influenza virus (cIV). A comprehensive analysis of 97 studies spanning 27 countries revealed that seroprevalence of various influenza strains in dogs consistently registered below 10% and exhibited relative stability over the past decade. Significantly, we noted that seroprevalence of human influenza virus was notably higher in pet dogs compared to their non-pet counterparts, whereas seroprevalence of other influenza strains remained relatively uniform among both categories of dogs. Seasonal variations in seroprevalence of cIV were not observed. In summary, our findings indicated the global circulation of cIV strains H3N2 and H3N8, with other strains primarily confined to China. Given the lack of reported cases of the transmission of cIV from dogs to humans, our findings suggest a higher risk of reverse zoonosis than zoonosis. Finally, we strongly advocate for standardised reporting guidelines to underpin future canine influenza research endeavours.
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Enfermedades de los Perros , Infecciones por Orthomyxoviridae , Animales , Perros , Humanos , Enfermedades de los Perros/epidemiología , Enfermedades de los Perros/virología , Salud Global , Virus de la Influenza A/inmunología , Virus de la Influenza A/aislamiento & purificación , Subtipo H3N2 del Virus de la Influenza A/inmunología , Subtipo H3N2 del Virus de la Influenza A/aislamiento & purificación , Infecciones por Orthomyxoviridae/epidemiología , Infecciones por Orthomyxoviridae/veterinaria , Infecciones por Orthomyxoviridae/virología , Infecciones por Orthomyxoviridae/inmunología , Prevalencia , Estaciones del Año , Estudios SeroepidemiológicosRESUMEN
SignificanceMetagenomic pathogen sequencing offers an unbiased approach to characterizing febrile illness. In resource-scarce settings with high biodiversity, it is critical to identify disease-causing pathogens in order to understand burden and to prioritize efforts for control. Here, metagenomic next-generation sequencing (mNGS) characterization of the pathogen landscape in Cambodia revealed diverse vector-borne and zoonotic pathogens irrespective of age and gender as risk factors. Identification of key pathogens led to changes in national program surveillance. This study is a "real world" example of the use of mNGS surveillance of febrile individuals, executed in-country, to identify outbreaks of vector-borne, zoonotic, and other emerging pathogens in a resource-scarce setting.
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Susceptibilidad a Enfermedades , Recursos en Salud , Metagenoma , Metagenómica/métodos , Vigilancia en Salud Pública , Asia Sudoriental/epidemiología , Cambodia/epidemiología , Femenino , Fiebre/epidemiología , Fiebre/etiología , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Masculino , Estudios SeroepidemiológicosRESUMEN
Despite more than 300,000 rVSVΔG-ZEBOV-glycoprotein (GP) vaccine doses having been administered during Ebola virus disease (EVD) outbreaks in the Democratic Republic of the Congo (DRC) between 2018 and 2020, seroepidemiologic studies of vaccinated Congolese populations are lacking. This study examines the antibody response at 21 d and 6 mo postvaccination after single-dose rVSVΔG-ZEBOV-GP vaccination among EVD-exposed and potentially exposed populations in the DRC. We conducted a longitudinal cohort study of 608 rVSVΔG-ZEBOV-GP-vaccinated individuals during an EVD outbreak in North Kivu Province, DRC. Participants provided questionnaires and blood samples at three study visits (day 0, visit 1; day 21, visit 2; and month 6, visit 3). Anti-GP immunoglobulin G (IgG) antibody titers were measured in serum by the Filovirus Animal Nonclinical Group anti-Ebola virus GP IgG enzyme-linked immunosorbent assay. Antibody response was defined as an antibody titer that had increased fourfold from visit 1 to visit 2 and was above four times the lower limit of quantification at visit 2; antibody persistence was defined as a similar increase from visit 1 to visit 3. We then examined demographics for associations with follow-up antibody titers using generalized linear mixed models. A majority of the sample, 87.2%, had an antibody response at visit 2, and 95.6% demonstrated antibody persistence at visit 3. Being female and of young age was predictive of a higher antibody titer postvaccination. Antibody response and persistence after Ebola vaccination was robust in this cohort, confirming findings from outside of the DRC.
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Vacunas contra el Virus del Ébola/inmunología , Ebolavirus/inmunología , Fiebre Hemorrágica Ebola/inmunología , Inmunogenicidad Vacunal/inmunología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Antivirales/inmunología , Niño , República Democrática del Congo , Brotes de Enfermedades/prevención & control , Femenino , Glicoproteínas/inmunología , Humanos , Masculino , Persona de Mediana Edad , Estudios Seroepidemiológicos , Vacunación/métodos , Proteínas del Envoltorio Viral/inmunología , Adulto JovenRESUMEN
This was a follow-up study conducted in 2020 assessing changes in levels of type 2 poliovirus-neutralizing antibodies 2 years postimmunization in children who received inactivated poliovirus vaccine (IPV) in Karachi, Pakistan. Unexpectedly, the findings revealed an increase in seroprevalence of type 2 antibodies from 73.1% to 81.6% 1 year and 2 years after IPV, respectively. The increase in type 2 immunity could result from the intensive transmission of circulating vaccine-derived poliovirus type 2 (cVDPV2) in Karachi during the second year of IPV administration. This study suggests that the cVDPV2 outbreak detected in Pakistan infected large proportions of children in Karachi. Clinical Trials Registration . NCT03286803.
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Poliomielitis , Poliovirus , Niño , Humanos , Anticuerpos Antivirales , Estudios de Seguimiento , Pakistán/epidemiología , Vacuna Antipolio de Virus Inactivados , Vacuna Antipolio Oral , Estudios SeroepidemiológicosRESUMEN
BACKGROUND: The incidence of herpes zoster (HZ) has increased in the United States concurrent with decrease in herpes simplex virus (HSV) prevalence. We hypothesized that lack of HSV-elicited cross-reactive immunity to varicella-zoster virus (VZV) results in an increased risk of HZ. Using specimens from the placebo arm of the Shingles Prevention Study, we investigated whether persons who develop HZ are less likely to have prior HSV infection than persons who do not develop HZ, and whether HZ is less severe in persons with HSV than in HSV seronegative persons. METHODS: We conducted a nested case-control (1:2) study comparing the seroprevalence of HSV-1 and HSV-2 in cases (persons with polymerase chain reaction-confirmed HZ) to age-, sex-, and health-matched controls (persons without HZ). RESULTS: Sera from 639 study participants (213 cases and 426 controls) yielded definitive HSV antibody results and were analyzed. Overall, HSV seropositivity rate was 75%. HSV seronegativity was significantly higher in HZ cases than controls (30.5% vs 22.3%; P = .024), with a 55% higher risk of HZ in HSV seronegative than HSV seropositive participants. HSV seropositivity was associated with more severe HZ (P = .021). CONCLUSIONS: Our study demonstrated that prior infection with HSV partly protects against HZ.
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Herpes Simple , Herpes Zóster , Herpesvirus Humano 1 , Humanos , Herpes Simple/complicaciones , Herpes Simple/epidemiología , Herpesvirus Humano 3 , Estudios Seroepidemiológicos , Masculino , FemeninoRESUMEN
We obtained samples from the Department of Defense Serum Repository from soldiers who were stationed at Fort Liberty, North Carolina, between 1991 and 2019 to assess temporal trends in tick-borne rickettsiosis and ehrlichiosis. Serological evidence of infection was common, with nearly 1 in 5 (18.9%) demonstrating antibodies. We observed significant decreases in Rickettsia seroprevalence (adjusted odds ratio [aOR], 0.42 [95% CI, .27-.65], P = .0001) while over the same period Ehrlichia seroprevalence, albeit less common, nearly doubled (aOR, 3.61 [95% CI, 1.10-13.99], P = .048). The increase in Ehrlichia seroprevalence likely reflects increased transmission resulting from the expanding geographic range of the lone star tick.
Asunto(s)
Anticuerpos Antibacterianos , Ehrlichia , Ehrlichiosis , Personal Militar , Infecciones por Rickettsia , Rickettsia , Estudios Seroepidemiológicos , North Carolina/epidemiología , Humanos , Personal Militar/estadística & datos numéricos , Infecciones por Rickettsia/epidemiología , Infecciones por Rickettsia/microbiología , Infecciones por Rickettsia/inmunología , Ehrlichiosis/epidemiología , Rickettsia/inmunología , Masculino , Adulto , Femenino , Ehrlichia/inmunología , Anticuerpos Antibacterianos/sangre , Adulto Joven , Animales , Enfermedades por Picaduras de Garrapatas/epidemiología , Enfermedades por Picaduras de Garrapatas/microbiología , Persona de Mediana EdadRESUMEN
Strain-transcending antibodies against virulence-associated subsets of P. falciparum-infected erythrocyte surface antigens could protect children from severe malaria. However, the evidence supporting the existence of such antibodies is incomplete and inconsistent. One subset of surface antigens associated with severe malaria, rosette-mediating Plasmodium falciparum Erythrocyte Membrane Protein one (PfEMP1) variants, cause infected erythrocytes to bind to uninfected erythrocytes to form clusters of cells (rosettes) that contribute to microvascular obstruction and pathology. Here, we tested plasma from 80 individuals living in malaria-endemic regions for IgG recognition of the surface of four P. falciparum rosetting strains using flow cytometry. Broadly reactive plasma samples were then used in antibody elution experiments in which intact IgG was eluted from the surface of infected erythrocytes and transferred to heterologous rosetting strains to look for strain-transcending antibodies. We found that seroprevalence (percentage of positive plasma samples) against allopatric rosetting strains was high in adults (63%-93%) but lower in children (13%-48%). Strain-transcending antibodies were present in nine out of eleven eluted antibody experiments, with six of these recognizing multiple heterologous rosetting parasite strains. One eluate had rosette-disrupting activity against heterologous strains, suggesting PfEMP1 as the likely target of the strain-transcending antibodies. Naturally acquired strain-transcending antibodies to rosetting P. falciparum strains in humans have not been directly demonstrated previously. Their existence suggests that such antibodies could play a role in clinical protection and raises the possibility that conserved epitopes recognized by strain-transcending antibodies could be targeted therapeutically by monoclonal antibodies or vaccines.
Asunto(s)
Anticuerpos Antiprotozoarios , Inmunoglobulina G , Malaria Falciparum , Plasmodium falciparum , Humanos , Plasmodium falciparum/inmunología , Anticuerpos Antiprotozoarios/inmunología , Anticuerpos Antiprotozoarios/sangre , Malaria Falciparum/inmunología , Malaria Falciparum/parasitología , Niño , Adulto , Inmunoglobulina G/inmunología , Inmunoglobulina G/sangre , Preescolar , Adolescente , Proteínas Protozoarias/inmunología , Eritrocitos/parasitología , Eritrocitos/inmunología , Antígenos de Protozoos/inmunología , Femenino , Masculino , Adulto Joven , Persona de Mediana Edad , Estudios Seroepidemiológicos , Formación de Roseta , Citometría de FlujoRESUMEN
Laboratory testing has been a key tool in managing the SARS-CoV-2 global pandemic. While rapid antigen and PCR testing has proven useful for diagnosing acute SARS-CoV-2 infections, additional testing methods are required to understand the long-term impact of SARS-CoV-2 infections on immune response. Serological testing, a well-documented laboratory practice, measures the presence of antibodies in a sample to uncover information about host immunity. Although proposed applications of serological testing for clinical use have previously been limited, current research into SARS-CoV-2 has shown growing utility for serological methods in these settings. To name a few, serological testing has been used to identify patients with past infections and long-term active disease and to monitor vaccine efficacy. Test utility and result interpretation, however, are often complicated by factors that include poor test sensitivity early in infection, lack of immune response in some individuals, overlying infection and vaccination responses, lack of standardization of antibody titers/levels between instruments, unknown titers that confer immune protection, and large between-individual biological variation following infection or vaccination. Thus, the three major components of this review will examine (1) factors that affect serological test utility: test performance, testing matrices, seroprevalence concerns and viral variants, (2) patient factors that affect serological response: timing of sampling, age, sex, body mass index, immunosuppression and vaccination, and (3) informative applications of serological testing: identifying past infection, immune surveillance to guide health practices, and examination of protective immunity. SARS-CoV-2 serological testing should be beneficial for clinical care if it is implemented appropriately. However, as with other laboratory developed tests, use of SARS-CoV-2 serology as a testing modality warrants careful consideration of testing limitations and evaluation of its clinical utility.