RESUMO
As the effectiveness of a two-dose messenger RNA (mRNA) severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine regimen decreases with time, a third dose has been recommended. Here, we assessed immunogenicity, vaccine effectiveness and safety of the third BNT162b2 vaccine dose in a prospective cohort study of 12,413 healthcare workers (HCWs). Anti-RBD immunoglobulin G (IgG) levels were increased 1.7-fold after a third dose compared with following the second dose. Increased avidity from 61.1% (95% confidence interval (CI), 56.1-66.7) to 96.3% (95% CI, 94.2-98.5) resulted in a 6.1-fold increase in neutralization titer. Peri-infection humoral markers of 13 third-dose Delta variant of concern (VOC) breakthrough cases were lower compared with 52 matched controls. Vaccine effectiveness of the third dose relative to two doses was 85.6% (95% CI, 79.2-90.1). No serious adverse effects were reported. These results suggest that the third dose is superior to the second dose in both quantity and quality of IgG antibodies and safely boosts protection from infection.
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COVID-19 , Vacinas , Anticorpos Antivirais , Vacina BNT162 , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Humanos , Imunogenicidade da Vacina , Imunoglobulina G , Estudos Prospectivos , SARS-CoV-2RESUMO
Although a vaccine against SARS-CoV-2 Omicron-XBB.1.5 variant is available worldwide and recent infection is protective, the lack of recorded infection data highlights the need to assess variant-specific antibody neutralization levels. We analyzed IgG levels against receptor-binding domain-specific SARS-CoV-2 ancestral strain as a correlate for high neutralizing titers against XBB variants.
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Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19 , Imunoglobulina G , SARS-CoV-2 , Humanos , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , SARS-CoV-2/imunologia , SARS-CoV-2/genética , COVID-19/imunologia , COVID-19/epidemiologia , COVID-19/prevenção & controle , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Israel/epidemiologia , Glicoproteína da Espícula de Coronavírus/imunologia , Glicoproteína da Espícula de Coronavírus/genética , Vacinas contra COVID-19/imunologia , Masculino , Adulto , Pessoa de Meia-Idade , Feminino , Idoso , Testes de NeutralizaçãoRESUMO
BACKGROUND: Despite high vaccine coverage and effectiveness, the incidence of symptomatic infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been increasing in Israel. Whether the increasing incidence of infection is due to waning immunity after the receipt of two doses of the BNT162b2 vaccine is unclear. METHODS: We conducted a 6-month longitudinal prospective study involving vaccinated health care workers who were tested monthly for the presence of anti-spike IgG and neutralizing antibodies. Linear mixed models were used to assess the dynamics of antibody levels and to determine predictors of antibody levels at 6 months. RESULTS: The study included 4868 participants, with 3808 being included in the linear mixed-model analyses. The level of IgG antibodies decreased at a consistent rate, whereas the neutralizing antibody level decreased rapidly for the first 3 months with a relatively slow decrease thereafter. Although IgG antibody levels were highly correlated with neutralizing antibody titers (Spearman's rank correlation between 0.68 and 0.75), the regression relationship between the IgG and neutralizing antibody levels depended on the time since receipt of the second vaccine dose. Six months after receipt of the second dose, neutralizing antibody titers were substantially lower among men than among women (ratio of means, 0.64; 95% confidence interval [CI], 0.55 to 0.75), lower among persons 65 years of age or older than among those 18 to less than 45 years of age (ratio of means, 0.58; 95% CI, 0.48 to 0.70), and lower among participants with immunosuppression than among those without immunosuppression (ratio of means, 0.30; 95% CI, 0.20 to 0.46). CONCLUSIONS: Six months after receipt of the second dose of the BNT162b2 vaccine, humoral response was substantially decreased, especially among men, among persons 65 years of age or older, and among persons with immunosuppression.
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Anticorpos Neutralizantes/sangue , Vacina BNT162/imunologia , COVID-19/imunologia , Pessoal de Saúde , Imunogenicidade da Vacina , Imunoglobulina G/sangue , Adulto , Fatores Etários , Idoso , Anticorpos Antivirais/sangue , Índice de Massa Corporal , COVID-19/prevenção & controle , Estudos de Coortes , Feminino , Humanos , Imunização Secundária , Hospedeiro Imunocomprometido , Israel , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Fatores Sexuais , Fatores de Tempo , Eficácia de VacinasRESUMO
BACKGROUND: Despite the high efficacy of the BNT162b2 messenger RNA vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), rare breakthrough infections have been reported, including infections among health care workers. Data are needed to characterize these infections and define correlates of breakthrough and infectivity. METHODS: At the largest medical center in Israel, we identified breakthrough infections by performing extensive evaluations of health care workers who were symptomatic (including mild symptoms) or had known infection exposure. These evaluations included epidemiologic investigations, repeat reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assays, antigen-detecting rapid diagnostic testing (Ag-RDT), serologic assays, and genomic sequencing. Correlates of breakthrough infection were assessed in a case-control analysis. We matched patients with breakthrough infection who had antibody titers obtained within a week before SARS-CoV-2 detection (peri-infection period) with four to five uninfected controls and used generalized estimating equations to predict the geometric mean titers among cases and controls and the ratio between the titers in the two groups. We also assessed the correlation between neutralizing antibody titers and N gene cycle threshold (Ct) values with respect to infectivity. RESULTS: Among 1497 fully vaccinated health care workers for whom RT-PCR data were available, 39 SARS-CoV-2 breakthrough infections were documented. Neutralizing antibody titers in case patients during the peri-infection period were lower than those in matched uninfected controls (case-to-control ratio, 0.361; 95% confidence interval, 0.165 to 0.787). Higher peri-infection neutralizing antibody titers were associated with lower infectivity (higher Ct values). Most breakthrough cases were mild or asymptomatic, although 19% had persistent symptoms (>6 weeks). The B.1.1.7 (alpha) variant was found in 85% of samples tested. A total of 74% of case patients had a high viral load (Ct value, <30) at some point during their infection; however, of these patients, only 17 (59%) had a positive result on concurrent Ag-RDT. No secondary infections were documented. CONCLUSIONS: Among fully vaccinated health care workers, the occurrence of breakthrough infections with SARS-CoV-2 was correlated with neutralizing antibody titers during the peri-infection period. Most breakthrough infections were mild or asymptomatic, although persistent symptoms did occur.
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Vacinas contra COVID-19 , COVID-19/epidemiologia , Pessoal de Saúde/estatística & dados numéricos , Adulto , Doenças Assintomáticas , Vacina BNT162 , COVID-19/diagnóstico , COVID-19/prevenção & controle , Teste de Ácido Nucleico para COVID-19 , Estudos de Casos e Controles , Feminino , Humanos , Israel/epidemiologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Falha de TratamentoRESUMO
Between late 2023 and early 2024, two measles outbreaks occurred in Israel, each caused by importation of measles virus strains of respective B3 and D8 genotypes. In this study, we validate transmission pathways uncovered by epidemiological investigations using a rapid molecular approach, based on complete measles virus genomes. The presented findings support this rapid molecular approach in complementing conventional contact tracing and highlight its potential for informing public health interventions.
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Sarampo , Humanos , Epidemiologia Molecular , Israel/epidemiologia , Filogenia , Análise de Sequência de DNA , Sarampo/diagnóstico , Sarampo/epidemiologia , Vírus do Sarampo/genética , Surtos de Doenças , GenótipoRESUMO
This report describes an unusual surge of West Nile fever in Israel in June 2024, during which 125 cases were diagnosed, compared with 4 cases on average during June in previous years (2014-23). Of the cases, 64 (62.1%) had neuroinvasive disease and 12 (9.6%) died; the 2024 case fatality rate was not significantly elevated vs the average rate in 2014-23. The early rise could be related to a temperature increase in spring and early summer of 2024.
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Estações do Ano , Febre do Nilo Ocidental , Vírus do Nilo Ocidental , Israel/epidemiologia , Humanos , Febre do Nilo Ocidental/epidemiologia , Febre do Nilo Ocidental/diagnóstico , Febre do Nilo Ocidental/mortalidade , Vírus do Nilo Ocidental/isolamento & purificação , Masculino , Feminino , Surtos de Doenças , Pessoa de Meia-Idade , Adulto , Incidência , Idoso , Vigilância da PopulaçãoRESUMO
BACKGROUND: Despite high vaccine coverage, an increase in breakthrough coronavirus disease 2019 (COVID-19) infections, prompted administration of a third BNT162b2 dose to people aged >60 years in Israel since July 2021. Here, we report real-world immunogenicity following third dose. METHODS: Overall, 208 healthcare workers aged >60 years were included. Paired pre- and post-second and/or third dose immunoglobulin G (IgG) and neutralizing antibody titers were compared. A subpopulation of low responders to the second dose was also tested for T-cell activation. For 25 paired serum samples, we tested neutralization of wild-type vs neutralization of Delta and Lambda variants, pre- and post-third dose. Active surveillance of vaccine adverse events was conducted through surveys. RESULTS: A pronounced immune response was observed following the third dose, including a 33-fold and 51-fold increase in IgG and neutralizing antibody, respectively. The neutralizing antibody levels post-third dose were 9.34 times higher than post-second dose (geometric mean titer, 2598 [95% confidence interval {CI}, 2085-3237] vs 207 [95% CI, 126-339]). Nine previously low responders had a significant antibody increase post-third dose, and 7 of 9 showed increase in T-cell activation. Additionally, sera obtained post-third dose highly and comparably neutralized the wild-type and Delta and Lambda variants. Of 1056 responders to the adverse-event survey, none had serious events. CONCLUSIONS: We demonstrate a rapid and broad immune response to the third BNT162b2 dose in individuals >60 years of age.
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Vacina BNT162/imunologia , Vacinas contra COVID-19/imunologia , COVID-19/prevenção & controle , Imunogenicidade da Vacina , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Vacina BNT162/administração & dosagem , Vacina BNT162/efeitos adversos , COVID-19/epidemiologia , COVID-19/imunologia , Vacinas contra COVID-19/administração & dosagem , Vacinas contra COVID-19/efeitos adversos , Feminino , Pessoal de Saúde , Humanos , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , RNA Mensageiro , SARS-CoV-2RESUMO
BACKGROUND & AIMS: Immune responses of solid organ transplant recipients to 2 doses of the BNT162b2 mRNA anti-SARS-CoV-2 vaccine are impaired. The immunogenicity and safety of a third dose among liver transplant (LT) recipients are unknown. This work aimed to evaluate the immune response of LT recipients to a third dose of the BNT162b2 mRNA vaccine. METHODS: Consecutive LT recipients (n = 61) in follow-up at Sheba Medical Center were included. Receptor binding domain (RBD) IgG, neutralizing antibody (NA) titers, and T-cell levels before and 21-28 days after a third vaccine dose were determined. Adverse effects after the third dose were monitored. RESULTS: The median age of LT recipients was 65 years and 57.4% were male. The humoral immune response rate improved significantly, with 56% of patients showing a response before the third vaccine dose compared to 98% after the third dose. The cellular response in 12 evaluated patients improved significantly (p = 0.008). The geometric mean of anti-RBD IgG levels, NA levels, and T-cell count also increased significantly after the third dose. NA titers after the third dose negatively correlated with age (p = 0.03), mycophenolate mofetil treatment (p = 0.005), and combined immunosuppression as opposed to calcineurin inhibitor monotherapy (p = 0.001). After the third dose, adverse effects were reported by 37% of recipients and were mostly mild (local pain and fatigue). CONCLUSION: After a third BNT162b2 mRNA vaccine, the immune response improved significantly among LT recipients, without serious adverse effects. Further studies are needed to evaluate immune response durability and to determine the optimal number and schedule of booster vaccine doses. LAY SUMMARY: The Pfizer-Biotech BNT162b2SARS-CoV-2 vaccine induced significant immunity among liver transplant recipients after a third dose. The majority of the patients developed sufficient levels of both humoral and cellular immune responses. Factors that predict non-response were older age and immunosuppressive medications.
Assuntos
COVID-19 , Transplante de Fígado , Idoso , Anticorpos Antivirais , Vacina BNT162 , COVID-19/prevenção & controle , Feminino , Humanos , Imunidade Celular , Imunoglobulina G , Masculino , Transplantados , Vacinas Sintéticas , Vacinas de mRNARESUMO
Background: An impaired humoral response to full dose of BNT162b2 vaccine was observed in renal transplant recipients (RTR). Methods: To reveal predictors for humoral response to third vaccine, patients were stratified to positive (N = 85) and negative (N = 14) response groups based on receptor-binding domain (RBD) IgG ≥1.1 and neutralizing antibodies (NA) ≥ 16 dilution versus RBD IgG <1.1 or NA < 16, respectively. NA were detected using a SARS-CoV-2 pseudo-virus. Results: Response rate increased from 32.3% (32/99) before the third dose to 85.9% (85/99) post-third vaccine with a significant rise in geometric mean titers (GMTs) for RBD IgG and NA [0.79 (95% CI 0.65-0.96) vs. 3.08 (95% CI 2.76-3.45), p < 0.001 and 17.46 (95% CI 12.38-24.62) vs. 362.2 (95% CI 220.7-594.6), p < 0.001 respective. 80.6% (54/67) seroconverted and 96.9% (31/32) remained positive following the vaccine with a significant increase in GMTs for RBD IgG and NA. Age, ESRD secondary to diabetic nephropathy (DN) and renal allograft function were independent predictors for antibody response in RTR. Mycophenolic acid (MPA) use and dose had no impact on humoral response following the third booster. AEs were recorded for 70.1% of RTR population. Systemic AEs were more common in recipients with a positive humoral response as opposed to non-responders (45.2% versus 15.4% respectively, p = 0.04). Conclusion: 85.9% of RTR develop NA to BNT162b2 third vaccine, found effective in both negative and positive responders prior to the vaccine. Antigenic re-exposure overcame the suppressive effect of MPA on antibody response in RTR.
Assuntos
COVID-19 , Transplante de Rim , Anticorpos Neutralizantes , Anticorpos Antivirais , Vacina BNT162 , Vacinas contra COVID-19 , Humanos , Imunoglobulina G , Ácido Micofenólico , SARS-CoV-2 , TransplantadosRESUMO
Until recently, children and adolescents were not eligible for COVID-19 vaccination. They may have been a considerable source of SARS-CoV-2 spread. We evaluated SARS-CoV-2 IgG antibody seroprevalence in Israeli children aged 0-15 years from January 2020 to March 2021. Seropositivity was 1.8-5.5 times higher than COVID-19 incidence rates based on PCR testing. We found that SARS-CoV-2 infection among children is more prevalent than previously thought and emphasise the importance of seroprevalence studies to accurately estimate exposure.
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COVID-19 , Adolescente , Anticorpos Antivirais , Vacinas contra COVID-19 , Criança , Humanos , Israel/epidemiologia , SARS-CoV-2 , Estudos SoroepidemiológicosRESUMO
IntroductionThe COVID-19 pandemic has put healthcare workers (HCW) at significant risk. Presence of antibodies can confirm prior severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.AimThis study investigates the prevalence of IgA and IgG antibodies against SARS-CoV-2 in HCW.MethodsPerformance of IgA and IgG antibody ELISA assays were initially evaluated in positive and negative SARS-CoV-2 serum samples. IgA and IgG antibodies against SARS-CoV-2 were measured in 428 asymptomatic HCW. We assessed the risk of two groups: HCW with high exposure risk outside work (HROW) residing in areas where COVID-19 was endemic (n = 162) and HCW with high exposure risk at work (HRAW) in a COVID-19 intensive care unit (ICU) (n = 97).ResultsSensitivities of 80% and 81.2% and specificities of 97.2% and 98% were observed for IgA and IgG antibodies, respectively. Of the 428 HCW, three were positive for IgG and 27 for IgA. Only 3/27 (11%) IgA-positive HCW had IgG antibodies compared with 50/62 (81%) in a group of previous SARS-CoV-2-PCR-positive individuals. Consecutive samples from IgA-positive HCW demonstrated IgA persistence 18-83 days in 12/20 samples and IgG seroconversion in 1/20 samples. IgA antibodies were present in 8.6% of HROW and 2% of HRAW.ConclusionsSARS-CoV-2 exposure may lead to asymptomatic transient IgA response without IgG seroconversion. The significance of these findings needs further study. Out of work exposure is a possible risk of SARS-CoV-2 infection in HCW and infection in HCW can be controlled if adequate protective equipment is implemented.
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COVID-19 , SARS-CoV-2 , Anticorpos Antivirais , Pessoal de Saúde , Humanos , Imunoglobulina A , Israel , PandemiasRESUMO
West Nile virus is a notable cause of neuroinvasive disease, damage to the central nervous system, or even death. In this study, using metagenomics analysis and quantitative real-time PCR validation, we identified a JC virus infection in urine and cerebrospinal fluid samples of a West Nile virus patient with severe neurological symptoms and extended disease. JC virus is known to be involved in neurological complications, especially in immunocompromised individuals thus suggesting that the coinfection with JC virus is involved with the West Nile virus infection persistence and severe symptoms. JC virus was identified in urine samples from additional West Nile virus patients via quantitative real-time PCR, however, JC virus was not found in any cerebrospinal fluid samples of West Nile virus patients, suggesting that JC virus does not regularly infect the central nervous system of WNV patients. Overall, this study highlights the importance of identifying infection by opportunistic viruses in already-diagnosed patients and highlights the advantages of next-generation sequencing and metagenomics for viral diagnosis.
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Vírus JC/genética , Leucoencefalopatia Multifocal Progressiva/virologia , Febre do Nilo Ocidental/virologia , Vírus do Nilo Ocidental/genética , Doença Aguda , Coinfecção , DNA Viral/líquido cefalorraquidiano , DNA Viral/genética , DNA Viral/urina , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Vírus JC/isolamento & purificação , Leucoencefalopatia Multifocal Progressiva/líquido cefalorraquidiano , Leucoencefalopatia Multifocal Progressiva/diagnóstico , Leucoencefalopatia Multifocal Progressiva/urina , Metagenômica , RNA Viral/líquido cefalorraquidiano , RNA Viral/genética , RNA Viral/urina , Reação em Cadeia da Polimerase em Tempo Real , Febre do Nilo Ocidental/líquido cefalorraquidiano , Febre do Nilo Ocidental/diagnóstico , Febre do Nilo Ocidental/urina , Vírus do Nilo Ocidental/isolamento & purificaçãoRESUMO
JN.1, the dominating SARS-CoV-2 variant, is antigenically distinct from ancestral BA.1, BA.5 and XBB.1.5 variants, raising concern about effectiveness of updated COVID-19 vaccines. Here, we compared the neutralizing antibody response against JN.1, 1-month after receipt of the three available Moderna mRNA vaccines. Sera obtained from 37, 30 and 30 XBB.1.5, BA.1 and BA.4-5 -vaccine recipients, respectively, were tested for anti-RBD IgG and for JN-1 specific neutralizing antibody levels. Geometric mean fold rise (GMFR) in JN.1 specific neutralizing titers was 27 (95 % CI: 17-43.1), 10.1 (95 % CI: 6.48-15.7) and 8.77 (95 % CI: 5.69-13.5) following XBB.1.5, BA.1 and BA.4-5 vaccines, respectively, translating into a 64 % lower adjusted response (geometric mean ratio [GMR] = 0.36, 95 % CI: 0.21-0.6) in the BA.1 arm, and a 75 % lower response (GMR = 0.25, 95 % CI: 0.15-0.43) in the BA.4-5 arm. This suggests that XBB.1.5 vaccination will most likely, result in improved effectiveness against JN.1 compared with other COVID-19 vaccines.
RESUMO
BACKGROUND: Although there are some data regarding the COVID-19 vaccine and in in vitro fertilization (IVF) treatments, its potential impact in terms of serum immunoglobulin G (IgG) levels has not been evaluated prospectively. This study aimed to assess the effect of COVID-19 vaccine and IgG levels on IVF outcomes. METHODS: This observational, cohort study was conducted at a referral IVF unit. Couples undergoing IVF treatment during the COVID-19 vaccination period were recruited from March-April 2021. The study compared 38 women who had received the Pfizer mRNA COVID-19 vaccination to 10 women who had not and were not infected by the virus. We also compared pre- and post-vaccination IVF treatments for 24 women. The relation between serologic titers and IVF treatment outcomes was also assessed. RESULTS: No significant difference was found between the vaccinated and unvaccinated/uninfected groups regarding the main outcome measures. However, there was a trend toward a higher pregnancy rate for the unvaccinated group (57% vs. 23%, p = 0.078) but no difference in delivery rate (p = 0.236), gestational week (p = 0.537) or birth rate (p = 0.671). CONCLUSION: We cautiously state that the COVID-19 mRNA vaccine does not affect fertility outcomes, including fertilization, pregnancy and delivery rates, obstetric outcomes, and semen parameters, regardless of measured IgG levels.
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Vacinas contra COVID-19 , COVID-19 , Fertilização in vitro , Imunoglobulina G , SARS-CoV-2 , Humanos , Feminino , Imunoglobulina G/sangue , Gravidez , Adulto , COVID-19/prevenção & controle , COVID-19/imunologia , Vacinas contra COVID-19/imunologia , Vacinas contra COVID-19/administração & dosagem , SARS-CoV-2/imunologia , Estudos de Coortes , Masculino , Taxa de Gravidez , Anticorpos Antivirais/sangue , Vacinas de mRNARESUMO
In October 2023, the Tel Aviv District was notified of ten cases of measles. The outbreak initiated in a preschool with high vaccination coverage with one dose of MMR vaccine. Serological testing was available for eight patients (six children and two adults). Among the six children vaccinated with one dose of MMR vaccine, primary vaccine failure was demonstrated. Among the adults, secondary vaccine failure was confirmed. The outbreak was successfully contained due to a combination of factors, notably its occurrence within a population characterized by high vaccination coverage in Tel Aviv, during a period of restricted public interactions due to the prevailing state of war in the country. Despite challenging wartime conditions, effective prophylactic measures were promptly executed, encompassing a 2-dose MMR vaccination schedule for close contacts and the broader community of children in the TA district, successfully curbing the outbreak and preventing widespread infections.
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Surtos de Doenças , Vacina contra Sarampo-Caxumba-Rubéola , Sarampo , Cobertura Vacinal , Vacinação , Humanos , Sarampo/prevenção & controle , Sarampo/epidemiologia , Surtos de Doenças/prevenção & controle , Israel/epidemiologia , Pré-Escolar , Vacina contra Sarampo-Caxumba-Rubéola/administração & dosagem , Vacina contra Sarampo-Caxumba-Rubéola/imunologia , Masculino , Feminino , Adulto , Vacinação/estatística & dados numéricos , Cobertura Vacinal/estatística & dados numéricos , Criança , Lactente , Esquemas de Imunização , Adolescente , Adulto JovemRESUMO
BACKGROUND: The effectiveness of the fourth BNT162b2 vaccination in reducing the rate and severity of coronavirus disease 2019 (COVID-19) caused by the Omicron variant in renal transplant recipients (RTRs) is unknown. METHODS: Interviews were conducted with 447 RTRs regarding the status and timing of the fourth vaccination, prior vaccinations, and preceding COVID-19 infection. RTRs with polymerase chain reaction-confirmed COVID-19 infection from December 1, 2021, to the end of March 2022 were considered to have been infected with the Omicron variant and were interviewed to determine their disease severity. In a subgroup of 74 RTRs, the humoral response to the fourth dose was analyzed. In 30 RTRs, microneutralization assays were performed to reveal the humoral response to wild-type, Delta, and Omicron variant isolates before and after the fourth dose. RESULTS: Of 447 RTRs, 144 (32.2%) were infected with the Omicron variant, with 71 (49.3%) of the infected RTRs having received the fourth vaccine dose. RTRs who did not receive the fourth dose before the infection had more serious illness. In a subgroup of 74 RTRs, the fourth dose elicited a positive humoral response in 94.6% (70/74), with a significant increase in geometric mean titer for receptor-binding domain immunoglobulin G and neutralizing antibodies ( P < 0.001). The humoral responses to the Omicron variant before and after the fourth dose were significantly lower than the responses to the wild-type and the Delta variants. CONCLUSIONS: Overall, the fourth BNT162b2 dose was effective in reducing the rate and severity of Omicron disease in RTRs, despite the reduced humoral response to the variant.
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Vacinas contra COVID-19 , COVID-19 , Transplante de Rim , Humanos , Anticorpos Antivirais , Vacina BNT162 , COVID-19/prevenção & controle , Transplante de Rim/efeitos adversos , Gravidade do Paciente , SARS-CoV-2 , Vacinação , Vacinas contra COVID-19/efeitos adversosRESUMO
To study the differences in the immune response to SARS-CoV-2 infection compared to the response to vaccination, we characterized the humoral immune kinetics of these situations. In this prospective longitudinal study, we followed unvaccinated COVID-19-recovered individuals (n = 130) and naïve, two-dose BNT162b2-vaccinated individuals (n = 372) who were age- and BMI-matched for six months during the first pandemic year. Anti-RBD-IgG, neutralizing antibodies (NAbs), and avidity were assessed monthly. For recovered patients, data on symptoms and the severity of the disease were collected. Anti-RBD-IgG and NAbs titers at peak were higher after vaccination vs. after infection, but the decline was steeper (peak log IgG: 3.08 vs. 1.81, peak log NAbs: 5.93 vs. 5.04, slopes: -0.54 vs. -0.26). Peak anti-RBD-IgG and NAbs were higher in recovered individuals with BMI > 30 and in older individuals compared to individuals with BMI < 30, younger population. Of the recovered, 42 (36%) experienced long-COVID symptoms. Avidity was initially higher in vaccinated individuals compared with recovered individuals, though with time, it increased in recovered individuals but not among vaccinated individuals. Here, we show that while the initial antibody titers, neutralization, and avidity are lower in SARS-CoV-2-recovered individuals, they persist for a longer duration. These results suggest differential protection against COVID-19 in recovered-unvaccinated vs. naïve-vaccinated individuals.