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1.
N Engl J Med ; 384(6): 533-540, 2021 02 11.
Artigo em Inglês | MEDLINE | ID: mdl-33369366

RESUMO

BACKGROUND: The relationship between the presence of antibodies to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the risk of subsequent reinfection remains unclear. METHODS: We investigated the incidence of SARS-CoV-2 infection confirmed by polymerase chain reaction (PCR) in seropositive and seronegative health care workers attending testing of asymptomatic and symptomatic staff at Oxford University Hospitals in the United Kingdom. Baseline antibody status was determined by anti-spike (primary analysis) and anti-nucleocapsid IgG assays, and staff members were followed for up to 31 weeks. We estimated the relative incidence of PCR-positive test results and new symptomatic infection according to antibody status, adjusting for age, participant-reported gender, and changes in incidence over time. RESULTS: A total of 12,541 health care workers participated and had anti-spike IgG measured; 11,364 were followed up after negative antibody results and 1265 after positive results, including 88 in whom seroconversion occurred during follow-up. A total of 223 anti-spike-seronegative health care workers had a positive PCR test (1.09 per 10,000 days at risk), 100 during screening while they were asymptomatic and 123 while symptomatic, whereas 2 anti-spike-seropositive health care workers had a positive PCR test (0.13 per 10,000 days at risk), and both workers were asymptomatic when tested (adjusted incidence rate ratio, 0.11; 95% confidence interval, 0.03 to 0.44; P = 0.002). There were no symptomatic infections in workers with anti-spike antibodies. Rate ratios were similar when the anti-nucleocapsid IgG assay was used alone or in combination with the anti-spike IgG assay to determine baseline status. CONCLUSIONS: The presence of anti-spike or anti-nucleocapsid IgG antibodies was associated with a substantially reduced risk of SARS-CoV-2 reinfection in the ensuing 6 months. (Funded by the U.K. Government Department of Health and Social Care and others.).


Assuntos
Anticorpos Antivirais/sangue , COVID-19/imunologia , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Pessoal de Saúde , Imunoglobulina G/imunologia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , COVID-19/diagnóstico , COVID-19/epidemiologia , Teste de Ácido Nucleico para COVID-19 , Teste Sorológico para COVID-19 , Feminino , Humanos , Imunoglobulina G/sangue , Incidência , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Recidiva , SARS-CoV-2/isolamento & purificação , Soroconversão , Reino Unido , Adulto Jovem
2.
Clin Infect Dis ; 74(7): 1208-1219, 2022 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-34216472

RESUMO

BACKGROUND: Natural and vaccine-induced immunity will play a key role in controlling the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. SARS-CoV-2 variants have the potential to evade natural and vaccine-induced immunity. METHODS: In a longitudinal cohort study of healthcare workers (HCWs) in Oxfordshire, United Kingdom, we investigated the protection from symptomatic and asymptomatic polymerase chain reaction (PCR)-confirmed SARS-CoV-2 infection conferred by vaccination (Pfizer-BioNTech BNT162b2, Oxford-AstraZeneca ChAdOx1 nCOV-19) and prior infection (determined using anti-spike antibody status), using Poisson regression adjusted for age, sex, temporal changes in incidence and role. We estimated protection conferred after 1 versus 2 vaccinations and from infections with the B.1.1.7 variant identified using whole genome sequencing. RESULTS: In total, 13 109 HCWs participated; 8285 received the Pfizer-BioNTech vaccine (1407 two doses), and 2738 the Oxford-AstraZeneca vaccine (49 two doses). Compared to unvaccinated seronegative HCWs, natural immunity and 2 vaccination doses provided similar protection against symptomatic infection: no HCW vaccinated twice had symptomatic infection, and incidence was 98% lower in seropositive HCWs (adjusted incidence rate ratio 0.02 [95% confidence interval {CI} < .01-.18]). Two vaccine doses or seropositivity reduced the incidence of any PCR-positive result with or without symptoms by 90% (0.10 [95% CI .02-.38]) and 85% (0.15 [95% CI .08-.26]), respectively. Single-dose vaccination reduced the incidence of symptomatic infection by 67% (0.33 [95% CI .21-.52]) and any PCR-positive result by 64% (0.36 [95% CI .26-.50]). There was no evidence of differences in immunity induced by natural infection and vaccination for infections with S-gene target failure and B.1.1.7. CONCLUSIONS: Natural infection resulting in detectable anti-spike antibodies and 2 vaccine doses both provide robust protection against SARS-CoV-2 infection, including against the B.1.1.7 variant.


Assuntos
COVID-19 , SARS-CoV-2 , Vacina BNT162 , COVID-19/epidemiologia , COVID-19/prevenção & controle , Vacinas contra COVID-19 , ChAdOx1 nCoV-19 , Estudos de Coortes , Pessoal de Saúde , Humanos , Imunoglobulinas , Incidência , Estudos Longitudinais , Vacinação
4.
Eur J Gastroenterol Hepatol ; 28(11): 1258-63, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27487966

RESUMO

BACKGROUND: Chronic hepatitis C is common in people who inject drugs (PWID) and this population serves as a reservoir for infection. Treatment levels are low among this group, ranging from 1 to 19%. We explored whether a nurse-initiated community treatment model increased uptake of and adherence to interferon-based therapies. METHODS: This was a cluster randomized trial of nurse-initiated versus physician-initiated antiviral therapy with pegylated interferon and ribavirin for hepatitis C virus in community clinics (trial registration: ISRCTN07774040). RESULTS: The proportion of participants initiating treatment during follow-up was 10% with nurse-initiated (6/62) and 9% with physician-initiated (6/76) therapy. Adherence was similar in both groups, with only one patient in each arm not adhering to therapy. There were no serious adverse events, but interferon-related side effects were common. Drug and alcohol use did not change during therapy. CONCLUSION: Despite easy access to antiviral therapy, uptake of treatment was poor, with no significant difference between the groups. Nurse-led initiation of interferon-based antiviral therapy in PWID did not lead to increased uptake of, response to or adherence with treatment. Further service improvement is unlikely to increase the proportion of PWID undergoing antiviral therapy for hepatitis C virus and early adoption of interferon-free regimens may increase the proportion initiating and completing treatment.


Assuntos
Antivirais/uso terapêutico , Enfermagem em Saúde Comunitária/organização & administração , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/enfermagem , Abuso de Substâncias por Via Intravenosa/complicações , Adulto , Antivirais/efeitos adversos , Quimioterapia Combinada , Feminino , Hepatite C Crônica/transmissão , Humanos , Interferon-alfa/efeitos adversos , Interferon-alfa/uso terapêutico , Masculino , Adesão à Medicação/estatística & dados numéricos , Pessoa de Meia-Idade , Polietilenoglicóis/efeitos adversos , Polietilenoglicóis/uso terapêutico , Proteínas Recombinantes/efeitos adversos , Proteínas Recombinantes/uso terapêutico , Ribavirina/efeitos adversos , Ribavirina/uso terapêutico , Resultado do Tratamento
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