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1.
N Engl J Med ; 386(13): 1207-1220, 2022 03 31.
Artículo en Inglés | MEDLINE | ID: mdl-35172051

RESUMEN

BACKGROUND: The duration and effectiveness of immunity from infection with and vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are relevant to pandemic policy interventions, including the timing of vaccine boosters. METHODS: We investigated the duration and effectiveness of immunity in a prospective cohort of asymptomatic health care workers in the United Kingdom who underwent routine polymerase-chain-reaction (PCR) testing. Vaccine effectiveness (≤10 months after the first dose of vaccine) and infection-acquired immunity were assessed by comparing the time to PCR-confirmed infection in vaccinated persons with that in unvaccinated persons, stratified according to previous infection status. We used a Cox regression model with adjustment for previous SARS-CoV-2 infection status, vaccine type and dosing interval, demographic characteristics, and workplace exposure to SARS-CoV-2. RESULTS: Of 35,768 participants, 27% (9488) had a previous SARS-CoV-2 infection. Vaccine coverage was high: 95% of the participants had received two doses (78% had received BNT162b2 vaccine [Pfizer-BioNTech] with a long interval between doses, 9% BNT162b2 vaccine with a short interval between doses, and 8% ChAdOx1 nCoV-19 vaccine [AstraZeneca]). Between December 7, 2020, and September 21, 2021, a total of 2747 primary infections and 210 reinfections were observed. Among previously uninfected participants who received long-interval BNT162b2 vaccine, adjusted vaccine effectiveness decreased from 85% (95% confidence interval [CI], 72 to 92) 14 to 73 days after the second dose to 51% (95% CI, 22 to 69) at a median of 201 days (interquartile range, 197 to 205) after the second dose; this effectiveness did not differ significantly between the long-interval and short-interval BNT162b2 vaccine recipients. At 14 to 73 days after the second dose, adjusted vaccine effectiveness among ChAdOx1 nCoV-19 vaccine recipients was 58% (95% CI, 23 to 77) - considerably lower than that among BNT162b2 vaccine recipients. Infection-acquired immunity waned after 1 year in unvaccinated participants but remained consistently higher than 90% in those who were subsequently vaccinated, even in persons infected more than 18 months previously. CONCLUSIONS: Two doses of BNT162b2 vaccine were associated with high short-term protection against SARS-CoV-2 infection; this protection waned considerably after 6 months. Infection-acquired immunity boosted with vaccination remained high more than 1 year after infection. (Funded by the U.K. Health Security Agency and others; ISRCTN Registry number, ISRCTN11041050.).


Asunto(s)
Inmunidad Adaptativa , Vacunas contra la COVID-19 , COVID-19 , SARS-CoV-2 , Inmunidad Adaptativa/inmunología , Enfermedades Asintomáticas , Vacuna BNT162/uso terapéutico , COVID-19/diagnóstico , COVID-19/inmunología , COVID-19/prevención & control , Prueba de Ácido Nucleico para COVID-19 , Vacunas contra la COVID-19/inmunología , Vacunas contra la COVID-19/uso terapéutico , ChAdOx1 nCoV-19/uso terapéutico , Personal de Salud , Humanos , Estudios Prospectivos , Reino Unido , Vacunación/métodos , Eficacia de las Vacunas
2.
Emerg Infect Dis ; 29(1): 184-188, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36454718

RESUMEN

Since June 2020, the SARS-CoV-2 Immunity and Reinfection Evaluation (SIREN) study has conducted routine PCR testing in UK healthcare workers and sequenced PCR-positive samples. SIREN detected increases in infections and reinfections and delected Omicron subvariant waves emergence contemporaneous with national surveillance. SIREN's sentinel surveillance methods can be used for variant surveillance.


Asunto(s)
COVID-19 , Humanos , Animales , COVID-19/diagnóstico , COVID-19/epidemiología , SARS-CoV-2/genética , Reino Unido/epidemiología , Personal de Salud , Reinfección , Urodelos
3.
Lancet ; 397(10283): 1459-1469, 2021 04 17.
Artículo en Inglés | MEDLINE | ID: mdl-33844963

RESUMEN

BACKGROUND: Increased understanding of whether individuals who have recovered from COVID-19 are protected from future SARS-CoV-2 infection is an urgent requirement. We aimed to investigate whether antibodies against SARS-CoV-2 were associated with a decreased risk of symptomatic and asymptomatic reinfection. METHODS: A large, multicentre, prospective cohort study was done, with participants recruited from publicly funded hospitals in all regions of England. All health-care workers, support staff, and administrative staff working at hospitals who could remain engaged in follow-up for 12 months were eligible to join The SARS-CoV-2 Immunity and Reinfection Evaluation study. Participants were excluded if they had no PCR tests after enrolment, enrolled after Dec 31, 2020, or had insufficient PCR and antibody data for cohort assignment. Participants attended regular SARS-CoV-2 PCR and antibody testing (every 2-4 weeks) and completed questionnaires every 2 weeks on symptoms and exposures. At enrolment, participants were assigned to either the positive cohort (antibody positive, or previous positive PCR or antibody test) or negative cohort (antibody negative, no previous positive PCR or antibody test). The primary outcome was a reinfection in the positive cohort or a primary infection in the negative cohort, determined by PCR tests. Potential reinfections were clinically reviewed and classified according to case definitions (confirmed, probable, or possible) and symptom-status, depending on the hierarchy of evidence. Primary infections in the negative cohort were defined as a first positive PCR test and seroconversions were excluded when not associated with a positive PCR test. A proportional hazards frailty model using a Poisson distribution was used to estimate incidence rate ratios (IRR) to compare infection rates in the two cohorts. FINDINGS: From June 18, 2020, to Dec 31, 2020, 30 625 participants were enrolled into the study. 51 participants withdrew from the study, 4913 were excluded, and 25 661 participants (with linked data on antibody and PCR testing) were included in the analysis. Data were extracted from all sources on Feb 5, 2021, and include data up to and including Jan 11, 2021. 155 infections were detected in the baseline positive cohort of 8278 participants, collectively contributing 2 047 113 person-days of follow-up. This compares with 1704 new PCR positive infections in the negative cohort of 17 383 participants, contributing 2 971 436 person-days of follow-up. The incidence density was 7·6 reinfections per 100 000 person-days in the positive cohort, compared with 57·3 primary infections per 100 000 person-days in the negative cohort, between June, 2020, and January, 2021. The adjusted IRR was 0·159 for all reinfections (95% CI 0·13-0·19) compared with PCR-confirmed primary infections. The median interval between primary infection and reinfection was more than 200 days. INTERPRETATION: A previous history of SARS-CoV-2 infection was associated with an 84% lower risk of infection, with median protective effect observed 7 months following primary infection. This time period is the minimum probable effect because seroconversions were not included. This study shows that previous infection with SARS-CoV-2 induces effective immunity to future infections in most individuals. FUNDING: Department of Health and Social Care of the UK Government, Public Health England, The National Institute for Health Research, with contributions from the Scottish, Welsh and Northern Irish governments.


Asunto(s)
Anticuerpos Antivirales/sangre , COVID-19/epidemiología , COVID-19/inmunología , Personal de Salud , Adulto , Infecciones Asintomáticas , COVID-19/diagnóstico , Prueba de Ácido Nucleico para COVID-19 , Inglaterra , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Pandemias , Estudios Prospectivos , Reinfección , Factores de Riesgo , SARS-CoV-2
4.
Lancet ; 397(10286): 1725-1735, 2021 05 08.
Artículo en Inglés | MEDLINE | ID: mdl-33901423

RESUMEN

BACKGROUND: BNT162b2 mRNA and ChAdOx1 nCOV-19 adenoviral vector vaccines have been rapidly rolled out in the UK from December, 2020. We aimed to determine the factors associated with vaccine coverage for both vaccines and documented the vaccine effectiveness of the BNT162b2 mRNA vaccine in a cohort of health-care workers undergoing regular asymptomatic testing. METHODS: The SIREN study is a prospective cohort study among staff (aged ≥18 years) working in publicly-funded hospitals in the UK. Participants were assigned into either the positive cohort (antibody positive or history of infection [indicated by previous positivity of antibody or PCR tests]) or the negative cohort (antibody negative with no previous positive test) at the beginning of the follow-up period. Baseline risk factors were collected at enrolment, symptom status was collected every 2 weeks, and vaccination status was collected through linkage to the National Immunisations Management System and questionnaires. Participants had fortnightly asymptomatic SARS-CoV-2 PCR testing and monthly antibody testing, and all tests (including symptomatic testing) outside SIREN were captured. Data cutoff for this analysis was Feb 5, 2021. The follow-up period was Dec 7, 2020, to Feb 5, 2021. The primary outcomes were vaccinated participants (binary ever vacinated variable; indicated by at least one vaccine dose recorded by at least one of the two vaccination data sources) for the vaccine coverage analysis and SARS-CoV-2 infection confirmed by a PCR test for the vaccine effectiveness analysis. We did a mixed-effect logistic regression analysis to identify factors associated with vaccine coverage. We used a piecewise exponential hazard mixed-effects model (shared frailty-type model) using a Poisson distribution to calculate hazard ratios to compare time-to-infection in unvaccinated and vaccinated participants and estimate the impact of the BNT162b2 vaccine on all PCR-positive infections (asymptomatic and symptomatic). This study is registered with ISRCTN, number ISRCTN11041050, and is ongoing. FINDINGS: 23 324 participants from 104 sites (all in England) met the inclusion criteria for this analysis and were enrolled. Included participants had a median age of 46·1 years (IQR 36·0-54·1) and 19 692 (84%) were female; 8203 (35%) were assigned to the positive cohort at the start of the analysis period, and 15 121 (65%) assigned to the negative cohort. Total follow-up time was 2 calendar months and 1 106 905 person-days (396 318 vaccinated and 710 587 unvaccinated). Vaccine coverage was 89% on Feb 5, 2021, 94% of whom had BNT162b2 vaccine. Significantly lower coverage was associated with previous infection, gender, age, ethnicity, job role, and Index of Multiple Deprivation score. During follow-up, there were 977 new infections in the unvaccinated cohort, an incidence density of 14 infections per 10 000 person-days; the vaccinated cohort had 71 new infections 21 days or more after their first dose (incidence density of eight infections per 10 000 person-days) and nine infections 7 days after the second dose (incidence density four infections per 10 000 person-days). In the unvaccinated cohort, 543 (56%) participants had typical COVID-19 symptoms and 140 (14%) were asymptomatic on or 14 days before their PCR positive test date, compared with 29 (36%) with typical COVID-19 symptoms and 15 (19%) asymptomatic in the vaccinated cohort. A single dose of BNT162b2 vaccine showed vaccine effectiveness of 70% (95% CI 55-85) 21 days after first dose and 85% (74-96) 7 days after two doses in the study population. INTERPRETATION: Our findings show that the BNT162b2 vaccine can prevent both symptomatic and asymptomatic infection in working-age adults. This cohort was vaccinated when the dominant variant in circulation was B1.1.7 and shows effectiveness against this variant. FUNDING: Public Health England, UK Department of Health and Social Care, and the National Institute for Health Research.


Asunto(s)
Vacunas contra la COVID-19/provisión & distribución , Personal de Salud , Enfermedades Profesionales/prevención & control , Exposición Profesional/prevención & control , ARN Mensajero , Vacuna BNT162 , Vacunas contra la COVID-19/administración & dosificación , Estudios de Cohortes , Inglaterra , Humanos , Estudios Prospectivos , Resultado del Tratamiento
5.
J Infect ; 88(1): 30-40, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37926119

RESUMEN

Third doses of COVID-19 vaccines were widely deployed following the primary vaccine course waning and the emergence of the Omicron-variant. We investigated protection from third-dose vaccines and previous infection against SARS-CoV-2 infection during Delta-variant and Omicron-variant (BA.1 & BA.2) waves in our frequently PCR-tested cohort of healthcare-workers. Relative effectiveness of BNT162b2 third doses and infection-acquired immunity was assessed by comparing the time to PCR-confirmed infection in boosted participants with those with waned dose-2 protection (≥254 days after dose-2), by primary series vaccination type. Follow-up time was divided by dominant circulating variant: Delta 07 September 2021 to 30 November 2021, Omicron 13 December 2021t o 28 February 2022. We used a Cox regression model with adjustment/stratification for demographic characteristics and staff-type. We explored protection associated with vaccination, infection and both. We included 19,614 participants, 29% previously infected. There were 278 primary infections (4 per 10,000 person-days of follow-up) and 85 reinfections (0.8/10,000 person-days) during the Delta period and 2467 primary infections (43/10,000 person-days) and 881 reinfections (33/10,000) during the Omicron period. Relative Vaccine Effectiveness (VE) 0-2 months post-3rd dose (3rd dose) (3-doses BNT162b2) in the previously uninfected cohort against Delta infections was 63% (95% Confidence Interval (CI) 40%-77%) and was lower (35%) against Omicron infection (95% CI 21%-47%). The relative VE of 3rd dose (heterologous BNT162b2) was greater for primary course ChAdOX1 recipients, with VE 0-2 months post-3rd dose over ≥68% higher for both variants. Third-dose protection waned rapidly against Omicron, with no significant difference between two and three BNT162b2 doses observed after 4-months. Previous infection continued to provide additional protection against Omicron (67% (CI 56%-75%) 3-6 months post-infection), but this waned to about 25% after 9-months, approximately three times lower than against Delta. Infection rates surged with Omicron emergence. Third doses of BNT162b2 vaccine provided short-term protection, with rapid waning against Omicron infections. Protection associated with infections incurred before Omicron was markedly diminished against the Omicron wave. Our findings demonstrate the complexity of an evolving pandemic with the potential emergence of immune-escape variants and the importance of continued monitoring.


Asunto(s)
Vacuna BNT162 , COVID-19 , Humanos , Estudios de Cohortes , COVID-19/prevención & control , Vacunas contra la COVID-19 , Vacunas de ARNm , Reinfección , SARS-CoV-2 , Reino Unido/epidemiología
6.
Lancet Reg Health Eur ; 36: 100809, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38111727

RESUMEN

Background: The protection of fourth dose mRNA vaccination against SARS-CoV-2 is relevant to current global policy decisions regarding ongoing booster roll-out. We aimed to estimate the effect of fourth dose vaccination, prior infection, and duration of PCR positivity in a highly-vaccinated and largely prior-COVID-19 infected cohort of UK healthcare workers. Methods: Participants underwent fortnightly PCR and regular antibody testing for SARS-CoV-2 and completed symptoms questionnaires. A multi-state model was used to estimate vaccine effectiveness (VE) against infection from a fourth dose compared to a waned third dose, with protection from prior infection and duration of PCR positivity jointly estimated. Findings: 1298 infections were detected among 9560 individuals under active follow-up between September 2022 and March 2023. Compared to a waned third dose, fourth dose VE was 13.1% (95% CI 0.9 to 23.8) overall; 24.0% (95% CI 8.5 to 36.8) in the first 2 months post-vaccination, reducing to 10.3% (95% CI -11.4 to 27.8) and 1.7% (95% CI -17.0 to 17.4) at 2-4 and 4-6 months, respectively. Relative to an infection >2 years ago and controlling for vaccination, 63.6% (95% CI 46.9 to 75.0) and 29.1% (95% CI 3.8 to 43.1) greater protection against infection was estimated for an infection within the past 0-6, and 6-12 months, respectively. A fourth dose was associated with greater protection against asymptomatic infection than symptomatic infection, whilst prior infection independently provided more protection against symptomatic infection, particularly if the infection had occurred within the previous 6 months. Duration of PCR positivity was significantly lower for asymptomatic compared to symptomatic infection. Interpretation: Despite rapid waning of protection, vaccine boosters remain an important tool in responding to the dynamic COVID-19 landscape; boosting population immunity in advance of periods of anticipated pressure, such as surging infection rates or emerging variants of concern. Funding: UK Health Security Agency, Medical Research Council, NIHR HPRU Oxford, Bristol, and others.

7.
J Infect ; 87(5): 420-427, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37689394

RESUMEN

OBJECTIVES: To investigate serological correlates of protection against SARS-CoV-2 B.1.617.2 (Delta) infection after two vaccinations. METHODS: We performed a case-control study, where cases were Delta infections after the second vaccine dose and controls were vaccinated, never infected participants, matched by age, gender and region. Sera were tested for anti-SARS-CoV-2 Spike antibody levels (anti-S) and neutralising antibody titres (nAbT), using live virus microneutralisation against Ancestral, Delta and Omicron (BA.1, B.1.1.529). We modelled the decay of anti-S and nAbT for both groups, inferring levels at matched calendar times since the second vaccination. We assessed differences in inferred antibody titres between groups and used conditional logistic regression to explore the relationship between titres and odds of infection. RESULTS: In total, 130 sequence-confirmed Delta cases and 318 controls were included. Anti-S and Ancestral nAbT decayed similarly between groups, but faster in cases for Delta nAbT (p = 0.02) and Omicron nAbT (p = 0.002). At seven days before infection, controls had higher anti-S levels (p < 0.0001) and nAbT (p < 0.0001; all variants) at matched calendar time. A two-fold increase in anti-S levels was associated with a 29% ([95% CI 14-42%]; p = 0.001) reduction in odds of Delta infection. Delta nAbT>40 were associated with reduced odds of Delta infection (89%, [69-96%]; p < 0.0001), with additional benefits for titres >100 (p = 0.009) and >400 (p = 0.007). CONCLUSIONS: We have identified correlates of protection against SARS-CoV-2 Delta, with potential implications for vaccine deployment, development, and public health response.


Asunto(s)
Hepatitis D , Vacunas , Humanos , Estudios de Casos y Controles , Anticuerpos Neutralizantes , Vacunación , Anticuerpos Antivirales , Reino Unido/epidemiología
8.
BMJ ; 378: e070379, 2022 07 20.
Artículo en Inglés | MEDLINE | ID: mdl-35858689

RESUMEN

OBJECTIVE: To describe the incidence of, risk factors for, and impact of vaccines on primary SARS-CoV-2 infection during the second wave of the covid-19 pandemic in susceptible hospital healthcare workers in England. DESIGN: Multicentre prospective cohort study. SETTING: National Health Service secondary care health organisations (trusts) in England between 1 September 2020 and 30 April 2021. PARTICIPANTS: Clinical, support, and administrative staff enrolled in the SARS-CoV-2 Immunity and Reinfection Evaluation (SIREN) study with no evidence of previous infection. Vaccination status was obtained from national covid-19 vaccination registries and self-reported. MAIN OUTCOME MEASURE: SARS-CoV-2 infection confirmed by polymerase chain reaction. Mixed effects logistic regression was conducted to determine demographic and occupational risk factors for infection, and an individual based mathematical model was used to predict how large the burden could have been if vaccines had not been available from 8 December 2020 . RESULTS: During England's second wave, 12.9% (2353/18 284) of susceptible SIREN participants became infected with SARS-CoV-2. Infections peaked in late December 2020 and decreased from January 2021, concurrent with the cohort's rapid vaccination coverage and a national lockdown. In multivariable analysis, factors increasing the likelihood of infection in the second wave were being under 25 years old (20.3% (132/651); adjusted odds ratio 1.35, 95% confidence interval 1.07 to 1.69), living in a large household (15.8% (282/1781); 1.54, 1.23 to 1.94, for participants from households of five or more people), having frequent exposure to patients with covid-19 (19.2% (723/3762); 1.79, 1.56 to 2.06, for participants with exposure every shift), working in an emergency department or inpatient ward setting (20.8% (386/1855); 1.76, 1.45 to 2.14), and being a healthcare assistant (18.1% (267/1479); 1.43, 1.16 to 1.77). Time to first vaccination emerged as being strongly associated with infection (P<0.001), with each additional day multiplying a participant's adjusted odds ratio by 1.02. Mathematical model simulations indicated that an additional 9.9% of all patient facing hospital healthcare workers would have been infected were it not for the rapid vaccination coverage. CONCLUSIONS: The rapid covid-19 vaccine rollout from December 2020 averted infection in a large proportion of hospital healthcare workers in England: without vaccines, second wave infections could have been 69% higher. With booster vaccinations being needed for adequate protection from the omicron variant, and perhaps the need for further boosters for future variants, ensuring equitable delivery to healthcare workers is essential. The findings also highlight occupational risk factors that persisted in healthcare workers despite vaccine rollout; a greater understanding of the transmission dynamics responsible for these is needed to help to optimise the infection prevention and control policies that protect healthcare workers from infection and therefore to support staffing levels and maintain healthcare provision. TRIAL REGISTRATION: ISRCTN registry ISRCTN11041050.


Asunto(s)
COVID-19 , Vacunas , Adulto , COVID-19/epidemiología , COVID-19/prevención & control , Vacunas contra la COVID-19 , Control de Enfermedades Transmisibles , Personal de Salud , Humanos , Modelos Teóricos , Pandemias/prevención & control , Estudios Prospectivos , SARS-CoV-2 , Medicina Estatal
9.
BMJ Open ; 12(6): e054336, 2022 06 28.
Artículo en Inglés | MEDLINE | ID: mdl-35768083

RESUMEN

INTRODUCTION: Understanding the effectiveness and durability of protection against SARS-CoV-2 infection conferred by previous infection and COVID-19 is essential to inform ongoing management of the pandemic. This study aims to determine whether prior SARS-CoV-2 infection or COVID-19 vaccination in healthcare workers protects against future infection. METHODS AND ANALYSIS: This is a prospective cohort study design in staff members working in hospitals in the UK. At enrolment, participants are allocated into cohorts, positive or naïve, dependent on their prior SARS-CoV-2 infection status, as measured by standardised SARS-CoV-2 antibody testing on all baseline serum samples and previous SARS-CoV-2 test results. Participants undergo monthly antibody testing and fortnightly viral RNA testing during follow-up and based on these results may move between cohorts. Any results from testing undertaken for other reasons (eg, symptoms, contact tracing) or prior to study entry will also be captured. Individuals complete enrolment and fortnightly questionnaires on exposures, symptoms and vaccination. Follow-up is 12 months from study entry, with an option to extend follow-up to 24 months.The primary outcome of interest is infection with SARS-CoV-2 after previous SARS-CoV-2 infection or COVID-19 vaccination during the study period. Secondary outcomes include incidence and prevalence (both RNA and antibody) of SARS-CoV-2, viral genomics, viral culture, symptom history and antibody/neutralising antibody titres. ETHICS AND DISSEMINATION: The study was approved by the Berkshire Research Ethics Committee, Health Research Authority (IRAS ID 284460, REC reference 20/SC/0230) on 22 May 2020; the vaccine amendment was approved on 12 January 2021. Participants gave informed consent before taking part in the study.Regular reports to national and international expert advisory groups and peer-reviewed publications ensure timely dissemination of findings to inform decision making. TRIAL REGISTRATION NUMBER: ISRCTN11041050.


Asunto(s)
COVID-19 , COVID-19/epidemiología , COVID-19/prevención & control , Vacunas contra la COVID-19 , Personal de Salud , Humanos , Incidencia , Estudios Multicéntricos como Asunto , Estudios Prospectivos , ARN Viral , Reinfección , SARS-CoV-2 , Reino Unido/epidemiología , Vacunación
10.
J Infect ; 85(5): 545-556, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36089104

RESUMEN

OBJECTIVES: To investigate serological differences between SARS-CoV-2 reinfection cases and contemporary controls, to identify antibody correlates of protection against reinfection. METHODS: We performed a case-control study, comparing reinfection cases with singly infected individuals pre-vaccination, matched by gender, age, region and timing of first infection. Serum samples were tested for anti-SARS-CoV-2 spike (anti-S), anti-SARS-CoV-2 nucleocapsid (anti-N), live virus microneutralisation (LV-N) and pseudovirus microneutralisation (PV-N). Results were analysed using fixed effect linear regression and fitted into conditional logistic regression models. RESULTS: We identified 23 cases and 92 controls. First infections occurred before November 2020; reinfections occurred before February 2021, pre-vaccination. Anti-S levels, LV-N and PV-N titres were significantly lower among cases; no difference was found for anti-N levels. Increasing anti-S levels were associated with reduced risk of reinfection (OR 0·63, CI 0·47-0·85), but no association for anti-N levels (OR 0·88, CI 0·73-1·05). Titres >40 were correlated with protection against reinfection for LV-N Wuhan (OR 0·02, CI 0·001-0·31) and LV-N Alpha (OR 0·07, CI 0·009-0·62). For PV-N, titres >100 were associated with protection against Wuhan (OR 0·14, CI 0·03-0·64) and Alpha (0·06, CI 0·008-0·40). CONCLUSIONS: Before vaccination, protection against SARS-CoV-2 reinfection was directly correlated with anti-S levels, PV-N and LV-N titres, but not with anti-N levels. Detectable LV-N titres were sufficient for protection, whilst PV-N titres >100 were required for a protective effect. TRIAL REGISTRATION NUMBER: ISRCTN11041050.


Asunto(s)
COVID-19 , SARS-CoV-2 , Anticuerpos Antivirales , COVID-19/prevención & control , Estudios de Casos y Controles , Humanos , Reinfección/prevención & control , Vacunación
11.
Contraception ; 88(1): 164-8, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23507169

RESUMEN

BACKGROUND: Despite the high contraceptive effectiveness and noncontraceptive benefits of the levonorgestrel-releasing intrauterine system (LNG-IUS) in nulligravidas, there are still concerns related to the use of this device. Pain at insertion is one of the limitations to the increased use of intrauterine contraceptives. The aim of the study was to evaluate the ease of insertion and occurrence of pain at insertion of the LNG-IUS in nulligravidas (women who never became pregnant) compared to parous women with and without cesarean section (c-section). We also assessed the difficulty at insertion in each group. METHODS: Three groups of new acceptors of the LNG-IUS were studied: one with 23 nulligravida women, one with 28 parous women who had undergone at least one c-section and one with 23 parous women who had no previous c-section. Pain at insertion was evaluated by using a pain visual analogue score (VAS). The ease of insertion was defined as easy or difficult by health care providers (HCPs) and classified according to the cause of difficulty: tight cervix, anatomically distorted uterus or pain. RESULTS: Almost all women reported pain at insertion, regardless of parity and form of delivery. The mean VAS was 6.6 for nulligravida women, 5.2 for parous women with c-section and 5.9 for parous women with no c-section. Although 93% of the women reported pain at insertion, they also reported a willingness to insert a new LNG-IUS again if needed. The most common difficulties were a tight cervix in nulligravidas, an anatomically distorted uterus in parous women with c-section and pain in parous women without c-section. There was no failure of insertion in any group. HCPs reported that it was easier to perform insertion in parous women who had undergone only vaginal deliveries than nulligravid women or parous women with a prior c-section. CONCLUSIONS: Although almost all women reported pain at insertion, they also reported a willingness to insert a new LNG-IUS if needed. This attitude reflects high satisfaction with the LNG-IUS. The type of difficulty at insertion was related to parity and type of delivery. The LNG-IUS was able to be inserted in all women; however, it was easier to do in parous women without c-section than nulligravid women or those with a prior C-section.


Asunto(s)
Anticonceptivos Femeninos , Dispositivos Intrauterinos Medicados/efectos adversos , Levonorgestrel , Adulto , Brasil , Cesárea/efectos adversos , Anticonceptivos Femeninos/administración & dosificación , Femenino , Estudios de Seguimiento , Humanos , Levonorgestrel/administración & dosificación , Ensayo de Materiales , Dimensión del Dolor , Paridad , Aceptación de la Atención de Salud , Satisfacción del Paciente , Embarazo , Estudios Prospectivos , Adulto Joven
12.
Rev Assoc Med Bras (1992) ; 56(6): 711-4, 2010.
Artículo en Portugués | MEDLINE | ID: mdl-21271141

RESUMEN

OBJECTIVE: Evaluate in outpatients, the endometrial morphology and histology of non-bleeding postmenopausal women. METHODS: We conducted a descriptive study where 52 menopausal women were selected, between 50 and 60 years of age, who had not used hormone replacement therapy in the last six months and did not present any kind of vaginal bleeding after menopause. These women underwent ultrasound examination, hysteroscopy and biopsy, and then endometrial findings were analyzed. RESULTS: Of the 52 women selected, thirty two (61.5%) had normal ultrasound, normal uterine cavity with atrophic endometrium, hysteroscopy, confirmed by endometrial biopsy. Twenty (38.4%) had hysteroscopic and histologic alterations and only five women showed by ultrasound an endometrial thickness of more than five millimeters. CONCLUSION: Diagnostic Hysteroscopy associated with aspiration biopsy (Pipelle) performed in the day care facility can reveal endometrial alterations that cannot be diagnosed by transvaginal ultrasound.


Asunto(s)
Endometrio , Posmenopausia , Biopsia con Aguja , Endometrio/diagnóstico por imagen , Endometrio/patología , Femenino , Humanos , Histeroscopía , Persona de Mediana Edad , Ultrasonografía
13.
Rev. Assoc. Med. Bras. (1992) ; 56(6): 711-714, 2010. tab
Artículo en Portugués | LILACS | ID: lil-572594

RESUMEN

OBJETIVO: Avaliar ambulatorialmente a morfologia e histologia endometrial de mulheres sem sangramento genital após a menopausa. MÉTODOS: Em estudo descritivo foram selecionadas 52 mulheres, após a menopausa, entre 50 e 60 anos, sem terapia hormonal nos últimos seis meses. Todas foram submetidas a exame ultrassonográfico, histeroscópico e biópsias endometriais. RESULTADOS: Das 52 mulheres selecionadas 32 (61,5 por cento) apresentaram ultrassonografia normal, cavidade uterina normal com endométrio atrófico à histeroscopia, confirmada pela biópsia endometrial. Vinte (38,4 por cento) apresentaram achados histeroscópicos ou histológicos anormais, sendo que apenas cinco destas mostraram endométrio com espessura superior a cinco milímetros ao ultrassom. CONCLUSÃO: A histeroscopia diagnóstica associada à biópsia aspirativa (Pipelle) pode evidenciar alterações não observadas ao ultrassom transvaginal.


OBJECTIVE: Evaluate in outpatients , the endometrial morphology and histology of non- bleeding postmenopausal women. METHODS: We conducted a descriptive study where 52 menopausal women were selected, between 50 and 60 years of age, who had not used hormone replacement therapy in the last six months and did not present any kind of vaginal bleeding after menopause. These women underwent ultrasound examination, hysteroscopy and biopsy, and then endometrial findings were analyzed. RESULTS: Of the 52 women selected, thirty two (61,5 percent) had normal ultrasound, normal uterine cavity with atrophic endometrium, hysteroscopy, confirmed by endometrial biopsy. Twenty (38,4 percent) had hysteroscopuc and histologic alterations and only five women showed by ultrasound an endometrial thickness of more than five millimeters. CONCLUSION: Diagnostic Hysteroscopy associated with aspiration biopsy (Pipelle) performed in the day care facility can reveal endometrial alterations that cannot be diagnosed by transvaginal ultrasound.


Asunto(s)
Femenino , Humanos , Persona de Mediana Edad , Endometrio , Posmenopausia , Biopsia con Aguja , Endometrio/patología , Endometrio , Histeroscopía
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