RESUMEN
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron (B.1.1.529) variant extensively escape neutralizing antibodies by vaccines or infection. We assessed serum neutralizing activity in sera from Delta infection after vaccination and Delta infection only against SARS-CoV-2 Wuhan-Hu-1 (WA1), Beta, Delta, and Omicron. Sera from Delta infection only could neutralize WA1 and Delta but almost completely lost capacity to neutralize Beta and Omicron. However, Delta infection after vaccination resulted in a significant increase of serum neutralizing activity against WA1, Beta, and Omicron. This study demonstrates that breakthrough infection of Delta substantially induced high potency humoral immune response against the Omicron variant and other emerged variants.
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Anticuerpos Neutralizantes , Vacunas contra la COVID-19 , COVID-19 , Inmunidad Humoral , Humanos , Anticuerpos Antivirales , COVID-19/inmunología , COVID-19/prevención & control , Pruebas de Neutralización , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Vacunación , Vacunas contra la COVID-19/inmunologíaRESUMEN
The severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1) survivors are more likely to produce a potent immune response to SARS-CoV-2 after booster vaccination. We assessed humoral and T cell responses against SARS-CoV-2 in previously vaccinated SARS-CoV-1 survivors and naïve healthy individuals (NHIs) after a booster Ad5-nCoV dose. Boosted SARS-CoV-1 survivors had a high neutralization of SARS-CoV-2 Wuhan-Hu-1 (WA1), Beta, and Delta but is limited to Omicron subvariants (BA.1, BA.2, BA.2.12.1, and BA.4/BA.5). Most boosted SARS-CoV-1 survivors had robust SARS-CoV-2-specific CD4+ and CD8+ T cell responses. While booster vaccination in NHIs elicited less or ineffective neutralization of WA1, Beta, and Delta, and none of them induced neutralizing antibodies against Omicron subvariants. However, they developed comparable SARS-CoV-2-specific T cell responses compared to boosted SARS-CoV-1 survivors. These findings suggest that boosted Ad5-nCoV would not elicit effective neutralizing antibodies against Omicron subvariants in SARS-CoV-1 survivors and NHIs but induced comparable robust T cell responses. Achieving a high antibody titer in SARS-CoV-1 survivors and NHIs is desirable to generate broad neutralization.
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Vacunas contra el SIDA , COVID-19 , Vacunas contra la Influenza , Vacunas contra Papillomavirus , Vacunas contra Virus Sincitial Respiratorio , Vacunas contra el SIDAS , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Vacuna BCG , Vacunas contra la COVID-19 , Vacuna contra Difteria, Tétanos y Tos Ferina , Humanos , Vacuna contra el Sarampión-Parotiditis-Rubéola , SARS-CoV-2 , SobrevivientesRESUMEN
BACKGROUND: The duration of humoral and T and B cell response after the infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains unclear. METHODS: We performed a cross-sectional study to assess the virus-specific antibody and memory T and B cell responses in coronavirus disease 2019 (COVID-19) patients up to 343 days after infection. Neutralizing antibodies and antibodies against the receptor-binding domain, spike, and nucleoprotein of SARS-CoV-2 were measured. Virus-specific memory T and B cell responses were analyzed. RESULTS: We enrolled 59 patients with COVID-19, including 38 moderate, 16 mild, and 5 asymptomatic patients; 31 (52.5%) were men and 28 (47.5%) were women. The median age was 41 years (interquartile range, 30-55). The median day from symptom onset to enrollment was 317 days (range 257 to 343 days). We found that approximately 90% of patients still have detectable immunoglobulin (Ig)G antibodies against spike and nucleocapsid proteins and neutralizing antibodies against pseudovirus, whereas ~60% of patients had detectable IgG antibodies against receptor-binding domain and surrogate virus-neutralizing antibodies. The SARS-CoV-2-specific IgG+ memory B cell and interferon-γ-secreting T cell responses were detectable in more than 70% of patients. CONCLUSIONS: Severe acute respiratory syndrome coronavirus 2-specific immune memory response persists in most patients approximately 1 year after infection, which provides a promising sign for prevention from reinfection and vaccination strategy.
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Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , COVID-19/inmunología , Inmunidad Celular/inmunología , Adulto , Linfocitos B/inmunología , Estudios Transversales , Femenino , Humanos , Inmunoglobulina G/inmunología , Memoria Inmunológica/inmunología , Masculino , Persona de Mediana Edad , Proteínas de la Nucleocápside/inmunología , SARS-CoV-2/inmunología , Glicoproteína de la Espiga del Coronavirus/inmunología , Linfocitos T/inmunologíaRESUMEN
We quantified the serum levels of 34 cytokines/chemokines in 30 patients with SARS-CoV-2 infection. Elevated levels of IP-10 and IL-7 were detected in the acute and convalescent stages of the infection and were highly associated with disease severity.
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COVID-19/sangre , Quimiocina CXCL10/sangre , Interleucina-7/sangre , SARS-CoV-2/metabolismo , Índice de Severidad de la Enfermedad , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Data concerning the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in asymptomatic and paucisymptomatic patients are lacking. We report a 3-family cluster of infections involving asymptomatic and paucisymptomatic transmission. Eight of 15 (53%) members from 3 families were confirmed with SARS-CoV-2 infection. Of 8 patients, 3 were asymptomatic and 1 was paucisymptomatic. An asymptomatic mother transmitted the virus to her son, and a paucisymptomatic father transmitted the virus to his 3-month-old daughter. SARS-CoV-2 was detected in the environment of 1 household. The complete genomes of SARS-CoV-2 from the patients were > 99.9% identical and were clustered with other SARS-CoV-2 sequences reported from China and other countries.
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Infecciones Asintomáticas , Infecciones por Coronavirus/transmisión , Neumonía Viral/transmisión , Adulto , Anciano , Betacoronavirus/genética , COVID-19 , China/epidemiología , Trazado de Contacto , Infecciones por Coronavirus/epidemiología , Salud de la Familia , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Pandemias , Filogenia , Neumonía Viral/epidemiología , Cuarentena , SARS-CoV-2RESUMEN
BACKGROUND: China is thought to be a hotspot for zoonotic influenza virus emergence, yet there have been few prospective studies examining the occupational risks of such infections. METHODS: We present the first 2 years of data collected from a 5-year, prospective, cohort study of swine-exposed and -unexposed participants at 6 swine farms in China. We conducted serological and virological surveillance to examine evidence for swine influenza A virus infection in humans. RESULTS: Of the 658 participants (521 swine-exposed and 137 swine-unexposed), 207 (31.5%) seroconverted against at least 1 swine influenza virus subtype (swine H1N1 or H3N2). Swine-exposed participants' microneutralization titers, especially those enrolled at confined animal feeding operations (CAFOs), were higher against the swine H1N1 virus than were other participants at 12 and 24 months. Despite elevated titers, among the 187 study subjects for whom we had complete follow-up, participants working at swine CAFOs had significantly greater odds of seroconverting against both the swine H1N1 (odds ratio [OR] 19.16, 95% confidence interval [CI] 3.55-358.65) and swine H3N2 (OR 2.97, 95% CI 1.16-8.01) viruses, compared to unexposed and non-CAFO swine workers with less intense swine exposure. CONCLUSIONS: While some of the observed increased risk against swine viruses may have been explained by exposure to human influenza strains, study data suggest that even with elevated preexisting antibodies, swine-exposed workers were at high risk of infection with enzootic swine influenza A viruses.
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Subtipo H1N1 del Virus de la Influenza A , Gripe Humana , Infecciones por Orthomyxoviridae , Enfermedades de los Porcinos , Animales , Anticuerpos Antivirales , China/epidemiología , Estudios de Cohortes , Subtipo H3N2 del Virus de la Influenza A , Gripe Humana/epidemiología , Infecciones por Orthomyxoviridae/epidemiología , Infecciones por Orthomyxoviridae/veterinaria , Estudios Prospectivos , Estudios Seroepidemiológicos , Porcinos , Enfermedades de los Porcinos/epidemiología , Zoonosis/epidemiologíaRESUMEN
We investigated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) environmental contamination in 2 rooms of a quarantine hotel after 2 presymptomatic persons who stayed there were laboratory-confirmed as having coronavirus disease. We detected SARS-CoV-2 RNA on 8 (36%) of 22 surfaces, as well as on the pillow cover, sheet, and duvet cover.
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Ropa de Cama y Ropa Blanca/virología , Betacoronavirus/aislamiento & purificación , Infecciones por Coronavirus/transmisión , Fómites/virología , Neumonía Viral/transmisión , ARN Viral/aislamiento & purificación , Adulto , Betacoronavirus/genética , COVID-19 , China/epidemiología , Infecciones por Coronavirus/prevención & control , Infecciones por Coronavirus/virología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pandemias/prevención & control , Neumonía Viral/prevención & control , Neumonía Viral/virología , Cuarentena , SARS-CoV-2Asunto(s)
Anticuerpos Neutralizantes/inmunología , Vacunas contra la COVID-19/inmunología , COVID-19/prevención & control , SARS-CoV-2/inmunología , Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , COVID-19/inmunología , Reacciones Cruzadas , Farmacorresistencia Viral , Humanos , Técnicas Microbiológicas , Mutación , Pruebas de Neutralización , SARS-CoV-2/genética , Glicoproteína de la Espiga del Coronavirus/genética , Estomatitis/virología , Vacunas de Productos Inactivados/inmunologíaRESUMEN
Sierra Leone is the most severely affected country by an unprecedented outbreak of Ebola virus disease (EVD) in West Africa. Although successfully contained, the transmission dynamics of EVD and the impact of interventions in the country remain unclear. We established a database of confirmed and suspected EVD cases from May 2014 to September 2015 in Sierra Leone and mapped the spatiotemporal distribution of cases at the chiefdom level. A Poisson transmission model revealed that the transmissibility at the chiefdom level, estimated as the average number of secondary infections caused by a patient per week, was reduced by 43% [95% confidence interval (CI): 30%, 52%] after October 2014, when the strategic plan of the United Nations Mission for Emergency Ebola Response was initiated, and by 65% (95% CI: 57%, 71%) after the end of December 2014, when 100% case isolation and safe burials were essentially achieved, both compared with before October 2014. Population density, proximity to Ebola treatment centers, cropland coverage, and atmospheric temperature were associated with EVD transmission. The household secondary attack rate (SAR) was estimated to be 0.059 (95% CI: 0.050, 0.070) for the overall outbreak. The household SAR was reduced by 82%, from 0.093 to 0.017, after the nationwide campaign to achieve 100% case isolation and safe burials had been conducted. This study provides a complete overview of the transmission dynamics of the 2014-2015 EVD outbreak in Sierra Leone at both chiefdom and household levels. The interventions implemented in Sierra Leone seem effective in containing the epidemic, particularly in interrupting household transmission.
Asunto(s)
Bases de Datos Factuales , Ebolavirus , Fiebre Hemorrágica Ebola/epidemiología , Fiebre Hemorrágica Ebola/terapia , Fiebre Hemorrágica Ebola/transmisión , Modelos Biológicos , Femenino , Humanos , Masculino , Sierra Leona/epidemiologíaRESUMEN
Background: Our understanding of influenza A virus transmission between humans and pigs is limited. Methods: Beginning in 2015, we used a One Health approach and serial sampling to prospectively study 299 swine workers and 100 controls, their 9000 pigs, and 6 pig farm environments in China for influenza A viruses (IAVs) using molecular, culture, and immunological techniques. Study participants were closely monitored for influenza-like illness (ILI) events. Results: Upon enrollment, swine workers had higher serum neutralizing antibody titers against swine H1N1 and higher nasal wash total immunoglobulin A (IgA) and specific IgA titers against swine H1N1 and H3N2 viruses. Over a period of 12 months, IAVs were detected by quantitative reverse-transcription polymerase chain reaction in 46 of 396 (11.6%) environmental swabs, 235 of 3300 (7.1%) pig oral secretion, 23 of 396 (5.8%) water, 20 of 396 (5.1%) aerosol, and 19 of 396 (4.8%) fecal-slurry specimens. Five of 32 (15.6%) participants with ILI events had nasopharyngeal swab specimens that were positive for IAV, and 17 (53.1%) demonstrated 4-fold rises in neutralization titers against a swine virus. Reassorted Eurasian avian-lineage H1N1, A(H1N1)pdm09-like, and swine-lineage H3N2 viruses were identified in pig farms. The A(H1N1)pdm09-like H1N1 viruses identified in swine were nearly genetically identical to the human H1N1 viruses isolated from the participants with ILI. Conclusions: There was considerable evidence of A(H1N1)pdm09-like, swine-lineage H1N1, and swine-lineage H3N2 viruses circulating, likely reassorting, and likely crossing species within the pig farms. These data suggest that stronger surveillance for novel influenza virus emergence within swine farms is imperative.
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Gripe Humana/transmisión , Infecciones por Orthomyxoviridae/transmisión , Virus Reordenados/patogenicidad , Enfermedades de los Porcinos/transmisión , Adolescente , Adulto , Anciano , Animales , Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Agricultores , Granjas/estadística & datos numéricos , Femenino , Humanos , Inmunidad Mucosa , Subtipo H1N1 del Virus de la Influenza A , Subtipo H3N2 del Virus de la Influenza A , Masculino , Persona de Mediana Edad , Salud Única , Infecciones por Orthomyxoviridae/inmunología , Estudios Prospectivos , Factores de Riesgo , Porcinos/virología , Zoonosis/transmisiónRESUMEN
We conducted a 3-year longitudinal serologic survey on an open cohort of poultry workers, swine workers, and general population controls to assess avian influenza A virus (AIV) seroprevalence and seroincidence and virologic diversity at live poultry markets (LPMs) in Wuxi City, Jiangsu Province, China. Of 964 poultry workers, 9 (0.93%) were seropositive for subtype H7N9 virus, 18 (1.87%) for H9N2, and 18 (1.87%) for H5N1. Of 468 poultry workers followed longitudinally, 2 (0.43%), 13 (2.78%), and 7 (1.5%) seroconverted, respectively; incidence was 1.27, 8.28, and 4.46/1,000 person-years for H7N9, H9N2, and H5N1 viruses, respectively. Longitudinal surveillance of AIVs at 9 LPMs revealed high co-circulation of H9, H7, and H5 subtypes. We detected AIVs in 726 (23.3%) of 3,121 samples and identified a high diversity (10 subtypes) of new genetic constellations and reassortant viruses. These data suggest that stronger surveillance for AIVs within LPMs and high-risk populations is imperative.
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Agricultores , Virus de la Influenza A , Gripe Humana/epidemiología , Gripe Humana/virología , Adulto , Anciano , Animales , China/epidemiología , Femenino , Geografía , Historia del Siglo XXI , Humanos , Incidencia , Virus de la Influenza A/clasificación , Virus de la Influenza A/genética , Gripe Aviar/virología , Gripe Humana/historia , Gripe Humana/transmisión , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Aves de Corral/virología , Vigilancia en Salud Pública , Factores de Riesgo , Estudios Seroepidemiológicos , PorcinosRESUMEN
Avian influenza A(H7N9) virus has caused 5 epidemic waves in China since its emergence in 2013. We investigated the dynamic changes of antibody response to this virus over 1 year postinfection in 25 patients in Suzhou City, Jiangsu Province, China, who had laboratory-confirmed infections during the fifth epidemic wave, October 1, 2016-February 14, 2017. Most survivors had relatively robust antibody responses that decreased but remained detectable at 1 year. Antibody response was variable; several survivors had low or undetectable antibody titers. Hemagglutination inhibition titer was >1:40 for <40% of the survivors. Measured in vitro in infected mice, hemagglutination inhibition titer predicted serum protective ability. Our findings provide a helpful serologic guideline for identifying subclinical infections and for developing effective vaccines and therapeutics to counter H7N9 virus infections.
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Anticuerpos Antivirales/inmunología , Subtipo H7N9 del Virus de la Influenza A/inmunología , Gripe Humana/epidemiología , Gripe Humana/inmunología , Anciano , Animales , Anticuerpos Antivirales/sangre , Femenino , Historia del Siglo XXI , Hospitalización , Humanos , Subtipo H7N9 del Virus de la Influenza A/clasificación , Gripe Humana/historia , Gripe Humana/virología , Masculino , Ratones , Persona de Mediana Edad , Pruebas Serológicas , SobrevivientesRESUMEN
BACKGROUND: In the last decade, scrub typhus (ST) has been emerging or re-emerging in some areas of Asia, including Guangzhou, one of the most affected endemic areas of ST in China. METHODS: Based on the data on all cases reported in Guangzhou from 2006 to 2014, we characterized the epidemiological features, and identified environmental determinants for the spatial distribution of ST using a panel negative binomial model. RESULTS: A total of 4821 scrub typhus cases were reported in Guangzhou during 2006-2014. The annual incidence increased noticeably and the increase was relatively high and rapid in rural townships and among elderly females. The majority of cases (86.8%) occurred during May-October, and farmers constituted the majority of the cases, accounting for 33.9% in urban and 61.6% in rural areas. The number of housekeeper patients had a rapid increment in both rural and urban areas during the study period. Atmospheric pressure and relative humidity with lags of 1 or 2 months, distributions of broadleaved forest and rural township were identified as determinants for the spatiotemporal distribution of scrub typhus. CONCLUSION: Our results indicate that surveillance and public education need to be focused on the elderly farmers in rural areas covered with broadleaf forest in southern China.
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Tifus por Ácaros/epidemiología , Anciano , Anciano de 80 o más Años , China/epidemiología , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Modelos Estadísticos , Factores de Riesgo , Población Rural/estadística & datos numéricos , Estaciones del AñoRESUMEN
BACKGROUND: Modern agricultural practices create environmental conditions conducive to the emergence of novel pathogens. Current surveillance efforts to assess the burden of emerging pathogens in animal production facilities in China are sparse. In Guangdong Province pig farms, we compared bioaerosol surveillance for influenza A virus to surveillance in oral pig secretions and environmental swab specimens. METHODS: During the 2014 summer and fall/winter seasons, we used 3 sampling techniques to study 5 swine farms weekly for influenza A virus. Samples were molecularly tested for influenza A virus, and positive specimens were further characterized with culture. Risk factors for influenza A virus positivity for each sample type were assessed. RESULTS: Seventy-one of 354 samples (20.1%) were positive for influenza A virus RNA by real-time reverse-transcription polymerase chain reaction analysis. Influenza A virus positivity in bioaerosol samples was a statistically significant predictor for influenza A virus positivity in pig oral secretion and environmental swab samples. Temperature of <20°C was a significant predictor of influenza A virus positivity in bioaerosol samples. DISCUSSIONS: Climatic factors and routine animal husbandry practices may increase the risk of human exposure to aerosolized influenza A viruses in swine farms. Data suggest that bioaerosol sampling in pig barns may be a noninvasive and efficient means to conduct surveillance for novel influenza viruses.
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Aerosoles , Crianza de Animales Domésticos , Microbiología Ambiental , Monitoreo del Ambiente , Virus de la Influenza A/aislamiento & purificación , Animales , China , Exposición a Riesgos Ambientales , Femenino , Humanos , Masculino , Enfermedades Profesionales/epidemiología , Enfermedades Profesionales/prevención & control , Reacción en Cadena en Tiempo Real de la Polimerasa , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Medición de Riesgo , PorcinosRESUMEN
UNLABELLED: Over the course of two waves of infection, H7N9 avian influenza A virus has caused 436 human infections and claimed 170 lives in China as of July 2014. To investigate the prevalence and genetic diversity of H7N9, we surveyed avian influenza viruses in poultry in Jiangsu province within the outbreak epicenter. We found frequent occurrence of H7N9/H9N2 coinfection in chickens. Molecular clock phylogenetic analysis confirms coinfection by H7N9/H9N2 viruses and also reveals that the identity of the H7N9 outbreak lineage is confounded by ongoing reassortment between outbreak viruses and diverse H9N2 viruses in domestic birds. Experimental inoculation of a coinfected sample in cell culture yielded two reassortant H7N9 strains with polymerase segments from the original H9N2 strain. Ongoing reassortment between the H7N9 outbreak lineage and diverse H9N2 viruses may generate new strains with the potential to infect humans, highlighting the need for continued viral surveillance in poultry and humans. IMPORTANCE: We found frequent occurrence of H7N9/H9N2 coinfection in chickens. The H7N9 outbreak lineage is confounded by ongoing reassortment between H7N9 and H9N2 viruses. The importance of H9N2 viruses as the source of novel avian influenza virus infections in humans requires continuous attention.
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Coinfección/veterinaria , Subtipo H7N9 del Virus de la Influenza A/aislamiento & purificación , Subtipo H9N2 del Virus de la Influenza A/aislamiento & purificación , Gripe Aviar/virología , Virus Reordenados/aislamiento & purificación , Animales , China/epidemiología , Coinfección/epidemiología , Coinfección/virología , Evolución Molecular , Subtipo H7N9 del Virus de la Influenza A/genética , Subtipo H9N2 del Virus de la Influenza A/genética , Gripe Aviar/epidemiología , Epidemiología Molecular , Aves de Corral , Virus Reordenados/genéticaRESUMEN
OBJECTIVE: To investigate the effects of repeated vaccination with ancestral SARS-CoV-2 (Wuhan-hu-1)-based inactivated, recombinant protein subunit or vector-based vaccines on the neutralizing antibody response to Omicron subvariants. METHODS: Individuals who received four-dose vaccinations with the Wuhan-hu-1 strain, individuals who were infected with the BA.5 variant alone without prior vaccination, and individuals who experienced a BA.5 breakthrough infection following receiving 2-4 doses of the Wuhan-hu-1 vaccine were enrolled. Neutralizing antibodies against D614G, BA.5, XBB.1.5, EG.5.1, and BA.2.86 were detected using a pseudovirus-based neutralization assay. Antigenic cartography was used to analyze cross-reactivity patterns among D614G, BA.5, XBB.1.5, EG.5.1, and BA.2.86 and sera from individuals. RESULTS: The highest neutralizing antibody titers against D614G were observed in individuals who only received four-dose vaccination and those who experienced BA.5 breakthrough infection, which was also significantly higher than the antibody titers against XBB.1.5, EG.5.1, and BA.2.86. In contrast, only BA.5 infection elicited comparable neutralizing antibody titers against the tested variants. While neutralizing antibody titers against D614G or BA.5 were similar across the cohorts, the neutralizing capacity of antibodies against XBB.1.5, EG.5.1, and BA.2.86 was significantly reduced. BA.5 breakthrough infection following heterologous booster induced significantly higher neutralizing antibody titers against the variants, particularly against XBB.1.5 and EG.5.1, than uninfected vaccinated individuals, only BA.5 infected individuals, or those with BA.5 breakthrough infection after primary vaccination. CONCLUSIONS: Our findings suggest that repeated vaccination with the Wuhan-hu-1 strain imprinted a neutralizing antibody response toward the Wuhan-hu-1 strain with limited effects on the antibody response to the Omicron subvariants.
RESUMEN
The ongoing emergence of SARS-CoV-2 variants poses challenges to the immunity induced by infections and vaccination. We conduct a 6-month longitudinal evaluation of antibody binding and neutralization of sera from individuals with six different combinations of vaccination and infection against BA.5, XBB.1.5, EG.5.1, and BA.2.86. We find that most individuals produce spike-binding IgG or neutralizing antibodies against BA.5, XBB.1.5, EG.5.1, and BA.2.86 2 months after infection or vaccination. However, compared to ancestral strain and BA.5 variant, XBB.1.5, EG.5.1, and BA.2.86 exhibit comparable but significant immune evasion. The spike-binding IgG and neutralizing antibody titers decrease in individuals without additional antigen exposure, and <50% of individuals neutralize XBB.1.5, EG.5.1, and BA.2.86 during the 6-month follow-up. Approximately 57% of the 107 followed up individuals experienced an additional infection, leading to improved binding IgG and neutralizing antibody levels against these variants. These findings provide insights into the impact of SARS-CoV-2 variants on immunity following repeated exposure.
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Anticuerpos Neutralizantes , Anticuerpos Antivirales , Vacunas contra la COVID-19 , COVID-19 , Inmunoglobulina G , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus , Vacunación , Humanos , SARS-CoV-2/inmunología , COVID-19/inmunología , COVID-19/prevención & control , COVID-19/virología , Anticuerpos Antivirales/inmunología , Anticuerpos Antivirales/sangre , Anticuerpos Neutralizantes/inmunología , Anticuerpos Neutralizantes/sangre , Vacunas contra la COVID-19/inmunología , Inmunoglobulina G/inmunología , Inmunoglobulina G/sangre , Glicoproteína de la Espiga del Coronavirus/inmunología , Femenino , Masculino , Adulto , Persona de Mediana Edad , Formación de Anticuerpos/inmunologíaRESUMEN
Six years have passed since the outbreak of severe acute respiratory syndrome (SARS). Previous studies indicated that specific Abs to SARS-related coronavirus (SARS-CoV) waned over time in recovered SARS patients. It is critical to find out whether a potential anamnestic response, as seen with other viral infections, exists to protect a person from reinfection in case of another SARS outbreak. Recovered SARS patients were followed up to 6 y to estimate the longevity of specific Ab. The specific memory B cell and T cell responses to SARS-CoV Ags were measured by means of ELISPOT assay. Factors in relation to humoral and cellular immunity were investigated. Six years postinfection, specific IgG Ab to SARS-CoV became undetectable in 21 of the 23 former patients. No SARS-CoV Ag-specific memory B cell response was detected in either 23 former SARS patients or 22 close contacts of SARS patients. Memory T cell responses to a pool of SARS-CoV S peptides were identified in 14 of 23 (60.9%) recovered SARS patients, whereas there was no such specific response in either close contacts or healthy controls. Patients with more severe clinical manifestations seemed to present a higher level of Ag-specific memory T cell response. SARS-specific IgG Ab may eventually vanish and peripheral memory B cell responses are undetectable in recovered SARS patients. In contrast, specific T cell anamnestic responses can be maintained for at least 6 y. These findings have applications in preparation for the possible reemergence of SARS.
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Linfocitos B/inmunología , Brotes de Enfermedades , Memoria Inmunológica/inmunología , Síndrome Respiratorio Agudo Grave/inmunología , Adulto , Antígenos Virales/análisis , Estudios de Casos y Controles , Ensayo de Immunospot Ligado a Enzimas , Femenino , Estudios de Seguimiento , Humanos , Inmunidad Celular , Inmunidad Humoral , Masculino , Persona de Mediana Edad , Coronavirus Relacionado al Síndrome Respiratorio Agudo Severo/inmunología , Linfocitos T/inmunologíaRESUMEN
Booster immunizations and breakthrough infections can elicit severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron subvariant neutralizing activity. However, the durability of the neutralization response is unknown. We characterize the sensitivity of BA.1, BA.2, BA.2.75, BA.4/BA.5, BF.7, BQ.1.1, and XBB against neutralizing antibodies from vaccination, hybrid immunity, and breakthrough infections 4-6 months after vaccination and infection. We show that a two-dose CoronaVac or a third-dose ZF2001 booster elicits limited neutralization against Omicron subvariants 6 months after vaccination. Hybrid immunity as well as Delta, BA.1, and BA.2 breakthrough infections induce long-term persistence of the antibody response, and over 70% of sera neutralize BA.1, BA.2, BA.4/BA.5, and BF.7. However, BQ.1.1 and XBB, followed by BA.2.75, are more resistant to neutralization, with neutralizing titer reductions of â¼9- to 41-fold, â¼16- to 63-fold, and â¼4- to 25-fold, respectively. These data highlight additional vaccination in CoronaVac- or ZF2001-vaccinated individuals and provide insight into the durability of neutralization against Omicron subvariants.