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1.
N Engl J Med ; 389(26): 2425-2435, 2023 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-38157500

RESUMEN

BACKGROUND: The safety of the monoclonal antibody nirsevimab and the effect of nirsevimab on hospitalizations for respiratory syncytial virus (RSV)-associated lower respiratory tract infection when administered in healthy infants are unclear. METHODS: In a pragmatic trial, we randomly assigned, in a 1:1 ratio, infants who were 12 months of age or younger, had been born at a gestational age of at least 29 weeks, and were entering their first RSV season in France, Germany, or the United Kingdom to receive either a single intramuscular injection of nirsevimab or standard care (no intervention) before or during the RSV season. The primary end point was hospitalization for RSV-associated lower respiratory tract infection, defined as hospital admission and an RSV-positive test result. A key secondary end point was very severe RSV-associated lower respiratory tract infection, defined as hospitalization for RSV-associated lower respiratory tract infection with an oxygen saturation of less than 90% and the need for supplemental oxygen. RESULTS: A total of 8058 infants were randomly assigned to receive nirsevimab (4037 infants) or standard care (4021 infants). Eleven infants (0.3%) in the nirsevimab group and 60 (1.5%) in the standard-care group were hospitalized for RSV-associated lower respiratory tract infection, which corresponded to a nirsevimab efficacy of 83.2% (95% confidence interval [CI], 67.8 to 92.0; P<0.001). Very severe RSV-associated lower respiratory tract infection occurred in 5 infants (0.1%) in the nirsevimab group and in 19 (0.5%) in the standard-care group, which represented a nirsevimab efficacy of 75.7% (95% CI, 32.8 to 92.9; P = 0.004). The efficacy of nirsevimab against hospitalization for RSV-associated lower respiratory tract infection was 89.6% (adjusted 95% CI, 58.8 to 98.7; multiplicity-adjusted P<0.001) in France, 74.2% (adjusted 95% CI, 27.9 to 92.5; multiplicity-adjusted P = 0.006) in Germany, and 83.4% (adjusted 95% CI, 34.3 to 97.6; multiplicity-adjusted P = 0.003) in the United Kingdom. Treatment-related adverse events occurred in 86 infants (2.1%) in the nirsevimab group. CONCLUSIONS: Nirsevimab protected infants against hospitalization for RSV-associated lower respiratory tract infection and against very severe RSV-associated lower respiratory tract infection in conditions that approximated real-world settings. (Funded by Sanofi and AstraZeneca; HARMONIE ClinicalTrials.gov number, NCT05437510).


Asunto(s)
Anticuerpos Monoclonales Humanizados , Infecciones por Virus Sincitial Respiratorio , Virus Sincitial Respiratorio Humano , Humanos , Lactante , Anticuerpos Monoclonales Humanizados/administración & dosificación , Anticuerpos Monoclonales Humanizados/efectos adversos , Anticuerpos Monoclonales Humanizados/uso terapéutico , Hospitalización , Infecciones por Virus Sincitial Respiratorio/prevención & control , Infecciones del Sistema Respiratorio/prevención & control , Inyecciones Intramusculares
2.
PLoS One ; 18(11): e0294133, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37943741

RESUMEN

Longitudinal, community-based sampling is important for understanding prevalence and transmission of respiratory pathogens. Using a minimally invasive sampling method, the FAMILY Micro study monitored the oral, nasal and hand microbiota of families for 6 months. Here, we explore participant experiences and opinions. A mixed methods approach was utilised. A quantitative questionnaire was completed after every sampling timepoint to report levels of discomfort and pain, as well as time taken to collect samples. Participants were also invited to discuss their experiences in a qualitative structured exit interview. We received questionnaires from 36 families. Most adults and children >5y experienced no pain (94% and 70%) and little discomfort (73% and 47% no discomfort) regardless of sample type, whereas children ≤5y experienced variable levels of pain and discomfort (48% no pain but 14% hurts even more, whole lot or worst; 38% no discomfort but 33% moderate, severe, or extreme discomfort). The time taken for saliva and hand sampling decreased over the study. We conducted interviews with 24 families. Families found the sampling method straightforward, and adults and children >5y preferred nasal sampling using a synthetic absorptive matrix over nasopharyngeal swabs. It remained challenging for families to fit sampling into their busy schedules. Adequate fridge/freezer space and regular sample pick-ups were found to be important factors for feasibility. Messaging apps proved extremely effective for engaging with participants. Our findings provide key information to inform the design of future studies, specifically that self-sampling at home using minimally invasive procedures is feasible in a family context.


Asunto(s)
Dolor , Manejo de Especímenes , Adulto , Niño , Humanos , Estudios de Factibilidad , Encuestas y Cuestionarios , Reino Unido
3.
Am J Respir Crit Care Med ; 208(8): 868-878, 2023 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-37556679

RESUMEN

Rationale: Pneumococcal pneumonia remains a global health problem. Pneumococcal colonization increases local and systemic protective immunity, suggesting that nasal administration of live attenuated Streptococcus pneumoniae (Spn) strains could help prevent infections. Objectives: We used a controlled human infection model to investigate whether nasopharyngeal colonization with attenuated S. pneumoniae strains protected against recolonization with wild-type (WT) Spn (SpnWT). Methods: Healthy adults aged 18-50 years were randomized (1:1:1:1) for nasal administration twice (at a 2-wk interval) with saline solution, WT Spn6B (BHN418), or one of two genetically modified Spn6B strains, SpnA1 (Δfhs/piaA) or SpnA3 (ΔproABC/piaA) (Stage I). After 6 months, participants were challenged with SpnWT to assess protection against the homologous serotype (Stage II). Measurements and Main Results: 125 participants completed both study stages per intention to treat. No serious adverse events were reported. In Stage I, colonization rates were similar among groups: SpnWT, 58.1% (18 of 31); SpnA1, 60% (18 of 30); and SpnA3, 59.4% (19 of 32). Anti-Spn nasal IgG levels after colonization were similar in all groups, whereas serum IgG responses were higher in the SpnWT and SpnA1 groups than in the SpnA3 group. In colonized individuals, increases in IgG responses were identified against 197 Spn protein antigens and serotype 6 capsular polysaccharide using a pangenome array. Participants given SpnWT or SpnA1 in Stage I were partially protected against homologous challenge with SpnWT (29% and 30% recolonization rates, respectively) at stage II, whereas those exposed to SpnA3 achieved a recolonization rate similar to that in the control group (50% vs. 47%, respectively). Conclusions: Nasal colonization with genetically modified live attenuated Spn was safe and induced protection against recolonization, suggesting that nasal administration of live attenuated Spn could be an effective strategy for preventing pneumococcal infections. Clinical trial registered with the ISRCTN registry (ISRCTN22467293).


Asunto(s)
Infecciones Neumocócicas , Streptococcus pneumoniae , Adulto , Humanos , Virulencia , Nariz , Infecciones Neumocócicas/prevención & control , Inmunización , Anticuerpos Antibacterianos , Inmunoglobulina G , Vacunas Neumococicas/uso terapéutico
4.
BMJ Open Respir Res ; 10(1)2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37277188

RESUMEN

INTRODUCTION: Respiratory syncytial virus (RSV) is a common respiratory virus, particularly affecting children, and can cause respiratory infections such as croup and bronchiolitis. The latter is a leading cause of paediatric hospitalisation within the UK. Children <3 years of age and/or with underlying health conditions are more vulnerable to severe RSV infection.There are currently limited data on the incidence of laboratory-confirmed RSV, particularly within primary care settings and outside the typical 'RSV season', which in the Northern hemisphere tends to coincide with winter months. There is also a lack of data on the health economic impact of RSV infection on families and healthcare systems.This observational surveillance study aims to collect data on the incidence of laboratory-confirmed RSV-attributable respiratory tract infection (RTI) in children aged <3 years presenting to primary, secondary or tertiary care; it also aims to estimate the health economic and quality of life impact of RSV-attributable infection in this cohort. Such data will contribute to informing public health strategies to prevent RSV-associated infection, including use of preventative medications. METHODS AND ANALYSIS: Parents/carers of children <3 years of age with RTI symptoms will consent for a respiratory sample (nasal swab) to be taken. Laboratory PCR testing will assess for the presence of RSV and/or other pathogens. Data will be obtained from medical records on demographics, comorbidities, severity of infection and hospitalisation outcomes. Parents will complete questionnaires on the impact of ongoing infection symptoms at day 14 and 28 following enrolment. The primary outcome is incidence of laboratory-confirmed RSV in children <3 years presenting to primary, secondary or tertiary care with RTI symptoms leading to health-seeking behaviours. Recruitment will be carried out from December 2021 to March 2023, encompassing two UK winter seasons and intervening months. ETHICS AND DISSEMINATION: Ethical approval has been granted (21/WS/0142), and study findings will be published as per International Committee of Medical Journal Editors' guidelines.


Asunto(s)
Infecciones por Virus Sincitial Respiratorio , Virus Sincitial Respiratorio Humano , Infecciones del Sistema Respiratorio , Niño , Humanos , Preescolar , Atención Terciaria de Salud , Incidencia , Calidad de Vida , Infecciones por Virus Sincitial Respiratorio/epidemiología , Infecciones por Virus Sincitial Respiratorio/prevención & control , Infecciones por Virus Sincitial Respiratorio/diagnóstico , Infecciones del Sistema Respiratorio/epidemiología , Infecciones del Sistema Respiratorio/prevención & control , Reino Unido/epidemiología
5.
PLoS One ; 18(5): e0284399, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37141259

RESUMEN

INTRODUCTION: Experimental Human Pneumococcal Challenge (EHPC) involves the controlled exposure of adults to a specific antibiotic-sensitive Streptococcus pneumoniae serotype, to induce nasopharyngeal colonisation for the purpose of vaccine research. The aims are to review comprehensively the safety profile of EHPC, explore the association between pneumococcal colonisation and frequency of safety review and describe the medical intervention required to undertake such studies. METHODS: A single-centre review of all EHPC studies performed 2011-2021. All recorded serious adverse events (SAE) in eligible studies are reported. An unblinded meta-analysis of collated anonymised individual patient data from eligible EHPC studies was undertaken to assess the association between experimental pneumococcal colonisation and the frequency of safety events following inoculation. RESULTS: In 1416 individuals (median age 21, IQR 20-25), 1663 experimental pneumococcal inoculations were performed. No pneumococcal-related SAE have occurred. 214 safety review events were identified with 182 (12.85%) participants presenting with symptoms potentially in keeping with pneumococcal infection, predominantly in pneumococcal colonised individuals (colonised = 96/658, non-colonised = 86/1005, OR 1.81 (95% CI 1.28-2.56, P = <0.001). The majority were mild (pneumococcal group = 72.7% [120/165 reported symptoms], non-pneumococcal = 86.7% [124/143 reported symptoms]). 1.6% (23/1416) required antibiotics for safety. DISCUSSION: No SAEs were identified directly relating to pneumococcal inoculation. Safety review for symptoms was infrequent but occurred more in experimentally colonised participants. Most symptoms were mild and resolved with conservative management. A small minority required antibiotics, notably those serotype 3 inoculated. CONCLUSION: Outpatient human pneumococcal challenge can be conducted safely with appropriate levels of safety monitoring procedures in place.


Asunto(s)
Infecciones Neumocócicas , Streptococcus pneumoniae , Adulto , Humanos , Adulto Joven , Infecciones Neumocócicas/prevención & control , Vacunas Neumococicas/efectos adversos , Nasofaringe , Antibacterianos/efectos adversos
6.
J Infect ; 86(6): 574-583, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37028454

RESUMEN

BACKGROUND: Heterologous COVID vaccine priming schedules are immunogenic and effective. This report aims to understand the persistence of immune response to the viral vectored, mRNA and protein-based COVID-19 vaccine platforms used in homologous and heterologous priming combinations, which will inform the choice of vaccine platform in future vaccine development. METHODS: Com-COV2 was a single-blinded trial in which adults ≥ 50 years, previously immunised with single dose 'ChAd' (ChAdOx1 nCoV-19, AZD1222, Vaxzevria, Astrazeneca) or 'BNT' (BNT162b2, tozinameran, Comirnaty, Pfizer/BioNTech), were randomised 1:1:1 to receive a second dose 8-12 weeks later with either the homologous vaccine, or 'Mod' (mRNA-1273, Spikevax, Moderna) or 'NVX' (NVX-CoV2373, Nuvaxovid, Novavax). Immunological follow-up and the secondary objective of safety monitoring were performed over nine months. Analyses of antibody and cellular assays were performed on an intention-to-treat population without evidence of COVID-19 infection at baseline or for the trial duration. FINDINGS: In April/May 2021, 1072 participants were enrolled at a median of 9.4 weeks after receipt of a single dose of ChAd (N = 540, 45% female) or BNT (N = 532, 39% female) as part of the national vaccination programme. In ChAd-primed participants, ChAd/Mod had the highest anti-spike IgG from day 28 through to 6 months, although the heterologous vs homologous geometric mean ratio (GMR) dropped from 9.7 (95% CI (confidence interval): 8.2, 11.5) at D28 to 6.2 (95% CI: 5.0, 7.7) at D196. The heterologous/homologous GMR for ChAd/NVX similarly dropped from 3.0 (95% CI:2.5,3.5) to 2.4 (95% CI:1.9, 3.0). In BNT-primed participants, decay was similar between heterologous and homologous schedules with BNT/Mod inducing the highest anti-spike IgG for the duration of follow-up. The adjusted GMR (aGMR) for BNT/Mod compared with BNT/BNT increased from 1.36 (95% CI: 1.17, 1.58) at D28 to 1.52 (95% CI: 1.21, 1.90) at D196, whilst for BNT/NVX this aGMR was 0.55 (95% CI: 0.47, 0.64) at day 28 and 0.62 (95% CI: 0.49, 0.78) at day 196. Heterologous ChAd-primed schedules produced and maintained the largest T-cell responses until D196. Immunisation with BNT/NVX generated a qualitatively different antibody response to BNT/BNT, with the total IgG significantly lower than BNT/BNT during all follow-up time points, but similar levels of neutralising antibodies. INTERPRETATION: Heterologous ChAd-primed schedules remain more immunogenic over time in comparison to ChAd/ChAd. BNT-primed schedules with a second dose of either mRNA vaccine also remain more immunogenic over time in comparison to BNT/NVX. The emerging data on mixed schedules using the novel vaccine platforms deployed in the COVID-19 pandemic, suggest that heterologous priming schedules might be considered as a viable option sooner in future pandemics. ISRCTN: 27841311 EudraCT:2021-001275-16.


Asunto(s)
COVID-19 , Vacunas , Adulto , Femenino , Humanos , Masculino , Vacunas contra la COVID-19 , ChAdOx1 nCoV-19 , Vacuna BNT162 , Pandemias , Método Simple Ciego , COVID-19/prevención & control , Vacunación , Inmunidad , Inmunoglobulina G , Anticuerpos Antivirales
7.
BMJ ; 380: e071883, 2023 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-36787910

RESUMEN

OBJECTIVE: To estimate the effectiveness, cost effectiveness (to be reported elsewhere), and safety of pharmacy independent prescribers in care homes. DESIGN: Cluster randomised controlled trial, with clusters based on triads of a pharmacist independent prescriber, a general practice, and one to three associated care homes. SETTING: Care homes across England, Scotland, and Northern Ireland, their associated general practices, and pharmacy independent prescribers, formed into triads. PARTICIPANTS: 49 triads and 882 residents were randomised. Participants were care home residents, aged ≥65 years, taking at least one prescribed drug, recruited to 20 residents/triad. INTERVENTION: Each pharmacy independent prescriber provided pharmaceutical care to approximately 20 residents across one to three care homes, with weekly visits over six months. Pharmacy independent prescribers developed a pharmaceutical care plan for each resident, did medicines reviews/reconciliation, trained staff, and supported with medicines related procedures, deprescribing, and authorisation of prescriptions. Participants in the control group received usual care. MAIN OUTCOMES MEASURES: The primary outcome was fall rate/person at six months analysed by intention to treat, adjusted for prognostic variables. Secondary outcomes included quality of life (EQ-5D by proxy), Barthel score, Drug Burden Index, hospital admissions, and mortality. Assuming a 21% reduction in falls, 880 residents were needed, allowing for 20% attrition. RESULTS: The average age of participants at study entry was 85 years; 70% were female. 697 falls (1.55 per resident) were recorded in the intervention group and 538 falls (1.26 per resident) in the control group at six months. The fall rate risk ratio for the intervention group compared with the control group was not significant (0.91, 95% confidence interval 0.66 to 1.26) after adjustment for all model covariates. Secondary outcomes were not significantly different between groups, with exception of the Drug Burden Index, which significantly favoured the intervention. A third (185/566; 32.7%) of pharmacy independent prescriber interventions involved medicines associated with falls. No adverse events or safety concerns were identified. CONCLUSIONS: Change in the primary outcome of falls was not significant. Limiting follow-up to six months combined with a small proportion of interventions predicted to affect falls may explain this. A significant reduction in the Drug Burden Index was realised and would be predicted to yield future clinical benefits for patients. This large trial of an intensive weekly pharmacist intervention with care home residents was also found to be safe and well received. TRIAL REGISTRATION: ISRCTN 17847169.


Asunto(s)
Servicios Farmacéuticos , Farmacéuticos , Humanos , Femenino , Anciano de 80 o más Años , Masculino , Calidad de Vida , Irlanda del Norte , Escocia
8.
PLoS One ; 18(1): e0280908, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36706119

RESUMEN

BACKGROUND: The SARS-CoV-2 pandemic has caused an unprecedented strain on healthcare systems worldwide, including the United Kingdom National Health Service (NHS). We conducted an observational cohort study of SARS-CoV-2 infection in frontline healthcare workers (HCW) working in an acute NHS Trust during the first wave of the pandemic, to answer emerging questions surrounding SARS-CoV-2 infection, diagnosis, transmission and control. METHODS: Using self-collected weekly saliva and twice weekly combined oropharyngeal/nasopharyngeal (OP/NP) samples, in addition to self-assessed symptom profiles and isolation behaviours, we retrospectively compared SARS-CoV-2 detection by RT-qPCR of saliva and OP/NP samples. We report the association with contemporaneous symptoms and isolation behaviour. RESULTS: Over a 12-week period from 30th March 2020, 40·0% (n = 34/85, 95% confidence interval 31·3-51·8%) HCW had evidence of SARS-CoV-2 infection by surveillance OP/NP swab and/or saliva sample. Symptoms were reported by 47·1% (n = 40) and self-isolation by 25·9% (n = 22) participants. Only 44.1% (n = 15/34) participants with SARS-CoV-2 infection reported any symptoms within 14 days of a positive result and only 29·4% (n = 10/34) reported self-isolation periods. Overall agreement between paired saliva and OP/NP swabs was 93·4% (n = 211/226 pairs) but rates of positive concordance were low. In paired samples with at least one positive result, 35·0% (n = 7/20) were positive exclusively by OP/NP swab, 40·0% (n = 8/20) exclusively by saliva and in only 25·0% (n = 5/20) were the OP/NP and saliva result both positive. CONCLUSIONS: HCW are a potential source of SARS-CoV-2 transmission in hospitals and symptom screening will identify the minority of infections. Without routine asymptomatic SARS-CoV-2 screening, it is likely that HCW with SARS-CoV-2 infection would continue to attend work. Saliva, in addition to OP/NP swab testing, facilitated ascertainment of symptomatic and asymptomatic SARS-CoV-2 infections. Combined saliva and OP/NP swab sampling would improve detection of SARS-CoV-2 for surveillance and is recommended for a high sensitivity strategy.


Asunto(s)
COVID-19 , Saliva , Humanos , COVID-19/diagnóstico , SARS-CoV-2 , Estudios de Cohortes , Estudios Retrospectivos , Medicina Estatal , Personal de Salud , Manejo de Especímenes , Nasofaringe
9.
Am J Respir Crit Care Med ; 206(11): 1379-1392, 2022 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-35802840

RESUMEN

Rationale: Streptococcus pneumoniae serotype 3 (SPN3) is a cause of invasive pneumococcal disease and associated with low carriage rates. Following the introduction of pediatric 13-valent pneumococcal conjugate vaccine (PCV13) programs, SPN3 declines are less than other vaccine serotypes and incidence has increased in some populations coincident with a shift in predominant circulating SPN3 clade, from I to II. A human challenge model provides an effective means for assessing the impact of PCV13 on SPN3 in the upper airway. Objectives: To establish SPN3's ability to colonize the nasopharynx using different inoculum clades and doses, and the safety of an SPN3 challenge model. Methods: In a human challenge study involving three well-characterized and antibiotic-sensitive SPN3 isolates (PFESP306 [clade Ia], PFESP231 [no clade], and PFESP505 [clade II]), inoculum doses (10,000, 20,000, 80,000, and 160,000 cfu/100 µl) were escalated until maximal colonization rates were achieved, with concurrent acceptable safety. Measurement and Main Results: Presence and density of experimental SPN3 nasopharyngeal colonization in nasal wash samples, assessed using microbiological culture and molecular methods, on Days 2, 7, and 14 postinoculation. A total of 96 healthy participants (median age 21, interquartile range 19-25) were inoculated (n = 6-10 per dose group, 10 groups). Colonization rates ranged from 30.0-70.0% varying with dose and isolate. 30.0% (29/96) reported mild symptoms (82.8% [24/29] developed a sore throat); one developed otitis media requiring antibiotics. No serious adverse events occurred. Conclusions: An SPN3 human challenge model is feasible and safe with comparable carriage rates to an established Serotype 6B human challenge model. SPN3 carriage may cause mild upper respiratory symptoms.


Asunto(s)
Infecciones Neumocócicas , Streptococcus pneumoniae , Humanos , Niño , Lactante , Adulto Joven , Adulto , Serogrupo , Portador Sano , Vacunas Neumococicas/uso terapéutico , Infecciones Neumocócicas/prevención & control , Nasofaringe/microbiología , Antibacterianos/uso terapéutico , Antibacterianos/farmacología
11.
Lancet Respir Med ; 10(11): 1049-1060, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35690076

RESUMEN

BACKGROUND: Priming COVID-19 vaccine schedules have been deployed at variable intervals globally, which might influence immune persistence and the relative importance of third-dose booster programmes. Here, we report exploratory analyses from the Com-COV trial, assessing the effect of 4-week versus 12-week priming intervals on reactogenicity and the persistence of immune response up to 6 months after homologous and heterologous priming schedules using the vaccines BNT162b2 (tozinameran, Pfizer/BioNTech) and ChAdOx1 nCoV-19 (AstraZeneca). METHODS: Com-COV was a participant-masked, randomised immunogenicity trial. For these exploratory analyses, we used the trial's general cohort, in which adults aged 50 years or older were randomly assigned to four homologous and four heterologous vaccine schedules using BNT162b2 and ChAdOx1 nCoV-19 with 4-week or 12-week priming intervals (eight groups in total). Immunogenicity analyses were done on the intention-to-treat (ITT) population, comprising participants with no evidence of SARS-CoV-2 infection at baseline or for the trial duration, to assess the effect of priming interval on humoral and cellular immune response 28 days and 6 months post-second dose, in addition to the effects on reactogenicity and safety. The Com-COV trial is registered with the ISRCTN registry, 69254139 (EudraCT 2020-005085-33). FINDINGS: Between Feb 11 and 26, 2021, 730 participants were randomly assigned in the general cohort, with 77-89 per group in the ITT analysis. At 28 days and 6 months post-second dose, the geometric mean concentration of anti-SARS-CoV-2 spike IgG was significantly higher in the 12-week interval groups than in the 4-week groups for homologous schedules. In heterologous schedule groups, we observed a significant difference between intervals only for the BNT162b2-ChAdOx1 nCoV-19 group at 28 days. Pseudotyped virus neutralisation titres were significantly higher in all 12-week interval groups versus 4-week groups, 28 days post-second dose, with geometric mean ratios of 1·4 (95% CI 1·1-1·8) for homologous BNT162b2, 1·5 (1·2-1·9) for ChAdOx1 nCoV-19-BNT162b2, 1·6 (1·3-2·1) for BNT162b2-ChAdOx1 nCoV-19, and 2·4 (1·7-3·2) for homologous ChAdOx1 nCoV-19. At 6 months post-second dose, anti-spike IgG geometric mean concentrations fell to 0·17-0·24 of the 28-day post-second dose value across all eight study groups, with only homologous BNT162b2 showing a slightly slower decay for the 12-week versus 4-week interval in the adjusted analysis. The rank order of schedules by humoral response was unaffected by interval, with homologous BNT162b2 remaining the most immunogenic by antibody response. T-cell responses were reduced in all 12-week priming intervals compared with their 4-week counterparts. 12-week schedules for homologous BNT162b2 and ChAdOx1 nCoV-19-BNT162b2 were up to 80% less reactogenic than 4-week schedules. INTERPRETATION: These data support flexibility in priming interval in all studied COVID-19 vaccine schedules. Longer priming intervals might result in lower reactogenicity in schedules with BNT162b2 as a second dose and higher humoral immunogenicity in homologous schedules, but overall lower T-cell responses across all schedules. Future vaccines using these novel platforms might benefit from schedules with long intervals. FUNDING: UK Vaccine Taskforce and National Institute for Health and Care Research.


Asunto(s)
Vacunas contra la COVID-19 , COVID-19 , Adulto , Humanos , Vacunas contra la COVID-19/efectos adversos , ChAdOx1 nCoV-19 , Vacuna BNT162 , COVID-19/prevención & control , Inmunización Secundaria , SARS-CoV-2 , Anticuerpos Antivirales , Inmunoglobulina G
12.
J Clin Invest ; 132(7)2022 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-35139037

RESUMEN

BackgroundAlthough recent epidemiological data suggest that pneumococci may contribute to the risk of SARS-CoV-2 disease, cases of coinfection with Streptococcus pneumoniae in patients with coronavirus disease 2019 (COVID-19) during hospitalization have been reported infrequently. This apparent contradiction may be explained by interactions of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and pneumococci in the upper airway, resulting in the escape of SARS-CoV-2 from protective host immune responses.MethodsHere, we investigated the relationship of these 2 respiratory pathogens in 2 distinct cohorts of health care workers with asymptomatic or mildly symptomatic SARS-CoV-2 infection identified by systematic screening and patients with moderate to severe disease who presented to the hospital. We assessed the effect of coinfection on host antibody, cellular, and inflammatory responses to the virus.ResultsIn both cohorts, pneumococcal colonization was associated with diminished antiviral immune responses, which primarily affected mucosal IgA levels among individuals with mild or asymptomatic infection and cellular memory responses in infected patients.ConclusionOur findings suggest that S. pneumoniae impair host immunity to SARS-CoV-2 and raise the question of whether pneumococcal carriage also enables immune escape of other respiratory viruses and facilitates reinfection.Trial registrationISRCTN89159899 (FASTER study) and ClinicalTrials.gov NCT03502291 (LAIV study).


Asunto(s)
COVID-19 , SARS-CoV-2 , Personal de Salud , Humanos , Inmunidad , Streptococcus pneumoniae
13.
Br J Cancer ; 126(2): 187-195, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34718357

RESUMEN

BACKGROUND: A two-phase 'respiratory symptoms' mass media campaign was conducted in 2016 and 2017 in England raising awareness of cough and worsening shortness of breath as symptoms warranting a general practitioner (GP) visit. METHOD: A prospectively planned pre-post evaluation was done using routinely collected data on 15 metrics, including GP attendance, GP referral, emergency presentations, cancers diagnosed (five metrics), cancer stage, investigations (two metrics), outpatient attendances, inpatient admissions, major lung resections and 1-year survival. The primary analysis compared 2015 with 2017. Trends in metrics over the whole period were also considered. The effects of the campaign on awareness of lung cancer symptoms were evaluated using bespoke surveys. RESULTS: There were small favourable statistically significant and clinically important changes over 2 years in 11 of the 15 metrics measured, including a 2.11% (95% confidence interval 1.02-3.20, p < 0.001) improvement in the percentage of lung cancers diagnosed at an early stage. However, these changes were not accompanied by increases in GP attendances. Furthermore, the time trends showed a gradual change in the metrics rather than steep changes occurring during or after the campaigns. CONCLUSION: There were small positive changes in most metrics relating to lung cancer diagnosis after this campaign. However, the pattern over time challenges whether the improvements are wholly attributable to the campaign. Given the importance of education on cancer in its own right, raising awareness of symptoms should remain important. However further research is needed to maximise the effect on health outcomes.


Asunto(s)
Detección Precoz del Cáncer , Médicos Generales/estadística & datos numéricos , Promoción de la Salud/métodos , Neoplasias Pulmonares/diagnóstico , Medios de Comunicación de Masas/normas , Anciano , Anciano de 80 o más Años , Inglaterra/epidemiología , Humanos , Neoplasias Pulmonares/epidemiología , Persona de Mediana Edad , Encuestas y Cuestionarios , Factores de Tiempo
14.
Lancet ; 399(10319): 36-49, 2022 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-34883053

RESUMEN

BACKGROUND: Given the importance of flexible use of different COVID-19 vaccines within the same schedule to facilitate rapid deployment, we studied mixed priming schedules incorporating an adenoviral-vectored vaccine (ChAdOx1 nCoV-19 [ChAd], AstraZeneca), two mRNA vaccines (BNT162b2 [BNT], Pfizer-BioNTech, and mRNA-1273 [m1273], Moderna) and a nanoparticle vaccine containing SARS-CoV-2 spike glycoprotein and Matrix-M adjuvant (NVX-CoV2373 [NVX], Novavax). METHODS: Com-COV2 is a single-blind, randomised, non-inferiority trial in which adults aged 50 years and older, previously immunised with a single dose of ChAd or BNT in the community, were randomly assigned (in random blocks of three and six) within these cohorts in a 1:1:1 ratio to receive a second dose intramuscularly (8-12 weeks after the first dose) with the homologous vaccine, m1273, or NVX. The primary endpoint was the geometric mean ratio (GMR) of serum SARS-CoV-2 anti-spike IgG concentrations measured by ELISA in heterologous versus homologous schedules at 28 days after the second dose, with a non-inferiority criterion of the GMR above 0·63 for the one-sided 98·75% CI. The primary analysis was on the per-protocol population, who were seronegative at baseline. Safety analyses were done for all participants who received a dose of study vaccine. The trial is registered with ISRCTN, number 27841311. FINDINGS: Between April 19 and May 14, 2021, 1072 participants were enrolled at a median of 9·4 weeks after receipt of a single dose of ChAd (n=540, 47% female) or BNT (n=532, 40% female). In ChAd-primed participants, geometric mean concentration (GMC) 28 days after a boost of SARS-CoV-2 anti-spike IgG in recipients of ChAd/m1273 (20 114 ELISA laboratory units [ELU]/mL [95% CI 18 160 to 22 279]) and ChAd/NVX (5597 ELU/mL [4756 to 6586]) was non-inferior to that of ChAd/ChAd recipients (1971 ELU/mL [1718 to 2262]) with a GMR of 10·2 (one-sided 98·75% CI 8·4 to ∞) for ChAd/m1273 and 2·8 (2·2 to ∞) for ChAd/NVX, compared with ChAd/ChAd. In BNT-primed participants, non-inferiority was shown for BNT/m1273 (GMC 22 978 ELU/mL [95% CI 20 597 to 25 636]) but not for BNT/NVX (8874 ELU/mL [7391 to 10 654]), compared with BNT/BNT (16 929 ELU/mL [15 025 to 19 075]) with a GMR of 1·3 (one-sided 98·75% CI 1·1 to ∞) for BNT/m1273 and 0·5 (0·4 to ∞) for BNT/NVX, compared with BNT/BNT; however, NVX still induced an 18-fold rise in GMC 28 days after vaccination. There were 15 serious adverse events, none considered related to immunisation. INTERPRETATION: Heterologous second dosing with m1273, but not NVX, increased transient systemic reactogenicity compared with homologous schedules. Multiple vaccines are appropriate to complete primary immunisation following priming with BNT or ChAd, facilitating rapid vaccine deployment globally and supporting recognition of such schedules for vaccine certification. FUNDING: UK Vaccine Task Force, Coalition for Epidemic Preparedness Innovations (CEPI), and National Institute for Health Research. NVX vaccine was supplied for use in the trial by Novavax.


Asunto(s)
Adyuvantes de Vacunas/administración & dosificación , Vacunas contra la COVID-19/administración & dosificación , Vacunas contra la COVID-19/efectos adversos , Inmunización Secundaria/efectos adversos , Inmunización Secundaria/métodos , Inmunogenicidad Vacunal , Vacunas de ARNm/administración & dosificación , Vacuna nCoV-2019 mRNA-1273/administración & dosificación , Vacuna nCoV-2019 mRNA-1273/inmunología , Anciano , Vacuna BNT162/administración & dosificación , Vacuna BNT162/inmunología , COVID-19/prevención & control , Vacunas contra la COVID-19/inmunología , ChAdOx1 nCoV-19/administración & dosificación , ChAdOx1 nCoV-19/inmunología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Método Simple Ciego , Reino Unido , Vacunación/efectos adversos , Vacunación/métodos , Vacunas de ARNm/inmunología
15.
Lancet ; 398(10303): 856-869, 2021 09 04.
Artículo en Inglés | MEDLINE | ID: mdl-34370971

RESUMEN

BACKGROUND: Use of heterologous prime-boost COVID-19 vaccine schedules could facilitate mass COVID-19 immunisation. However, we have previously reported that heterologous schedules incorporating an adenoviral vectored vaccine (ChAdOx1 nCoV-19, AstraZeneca; hereafter referred to as ChAd) and an mRNA vaccine (BNT162b2, Pfizer-BioNTech; hereafter referred to as BNT) at a 4-week interval are more reactogenic than homologous schedules. Here, we report the safety and immunogenicity of heterologous schedules with the ChAd and BNT vaccines. METHODS: Com-COV is a participant-blinded, randomised, non-inferiority trial evaluating vaccine safety, reactogenicity, and immunogenicity. Adults aged 50 years and older with no or well controlled comorbidities and no previous SARS-CoV-2 infection by laboratory confirmation were eligible and were recruited at eight sites across the UK. The majority of eligible participants were enrolled into the general cohort (28-day or 84-day prime-boost intervals), who were randomly assigned (1:1:1:1:1:1:1:1) to receive ChAd/ChAd, ChAd/BNT, BNT/BNT, or BNT/ChAd, administered at either 28-day or 84-day prime-boost intervals. A small subset of eligible participants (n=100) were enrolled into an immunology cohort, who had additional blood tests to evaluate immune responses; these participants were randomly assigned (1:1:1:1) to the four schedules (28-day interval only). Participants were masked to the vaccine received but not to the prime-boost interval. The primary endpoint was the geometric mean ratio (GMR) of serum SARS-CoV-2 anti-spike IgG concentration (measured by ELISA) at 28 days after boost, when comparing ChAd/BNT with ChAd/ChAd, and BNT/ChAd with BNT/BNT. The heterologous schedules were considered non-inferior to the approved homologous schedules if the lower limit of the one-sided 97·5% CI of the GMR of these comparisons was greater than 0·63. The primary analysis was done in the per-protocol population, who were seronegative at baseline. Safety analyses were done among participants receiving at least one dose of a study vaccine. The trial is registered with ISRCTN, 69254139. FINDINGS: Between Feb 11 and Feb 26, 2021, 830 participants were enrolled and randomised, including 463 participants with a 28-day prime-boost interval, for whom results are reported here. The mean age of participants was 57·8 years (SD 4·7), with 212 (46%) female participants and 117 (25%) from ethnic minorities. At day 28 post boost, the geometric mean concentration of SARS-CoV-2 anti-spike IgG in ChAd/BNT recipients (12 906 ELU/mL) was non-inferior to that in ChAd/ChAd recipients (1392 ELU/mL), with a GMR of 9·2 (one-sided 97·5% CI 7·5 to ∞). In participants primed with BNT, we did not show non-inferiority of the heterologous schedule (BNT/ChAd, 7133 ELU/mL) against the homologous schedule (BNT/BNT, 14 080 ELU/mL), with a GMR of 0·51 (one-sided 97·5% CI 0·43 to ∞). Four serious adverse events occurred across all groups, none of which were considered to be related to immunisation. INTERPRETATION: Despite the BNT/ChAd regimen not meeting non-inferiority criteria, the SARS-CoV-2 anti-spike IgG concentrations of both heterologous schedules were higher than that of a licensed vaccine schedule (ChAd/ChAd) with proven efficacy against COVID-19 disease and hospitalisation. Along with the higher immunogenicity of ChAd/BNT compared with ChAD/ChAd, these data support flexibility in the use of heterologous prime-boost vaccination using ChAd and BNT COVID-19 vaccines. FUNDING: UK Vaccine Task Force and National Institute for Health Research.


Asunto(s)
Vacunas contra la COVID-19/efectos adversos , Vacunas contra la COVID-19/inmunología , COVID-19/prevención & control , Inmunogenicidad Vacunal , Anciano , Anticuerpos Antivirales/sangre , Vacuna BNT162 , Vacunas contra la COVID-19/administración & dosificación , ChAdOx1 nCoV-19 , Estudios de Equivalencia como Asunto , Femenino , Humanos , Esquemas de Inmunización , Inmunoglobulina G/sangre , Análisis de Intención de Tratar , Masculino , Persona de Mediana Edad , Método Simple Ciego , Glicoproteína de la Espiga del Coronavirus/inmunología
16.
Eur J Cancer Care (Engl) ; 30(6): e13500, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34382254

RESUMEN

OBJECTIVE: A regional 'Be Clear on Cancer' (BCoC) campaign developed by Public Health England aimed to promote public awareness of key abdominal cancer symptoms in people aged 50 years and over. METHODS: Data were analysed for metrics at different stages in the patient care pathway including public awareness, GP attendance and referrals, to cancer diagnosis. RESULTS: There was significantly higher recognition of the BCoC abdominal campaign in the campaign region compared to the control area (Post Campaign/Control, n = 401/406; 35% vs. 24%, p < 0.05). The campaign significantly improved knowledge of 'bloating' as a symptom (p = 0.03) compared to pre-campaign levels. GP attendances for abdominal symptoms increased significantly by 5.8% (p = 0. 03), although the actual increase per practice was small (average 16.8 visits per week in 2016 to 17.7 in 2017). Urgent GP referrals for suspected abdominal cancer increased by 7.6%, compared to a non-significant change (0.05%) in the control area. For specific abdominal cancers, the number diagnosed were similar to or higher than the median in the campaign area but not in the control area in people aged 50 and over: colorectal (additional n = 61 cancers), pancreatic (additional n = 102) and stomach cancers (additional n = 17). CONCLUSIONS: This campaign had a modest impact on public awareness of abdominal cancer symptoms, GP attendances and cancers diagnosed.


Asunto(s)
Detección Precoz del Cáncer , Neoplasias Gástricas , Anciano , Concienciación , Conocimientos, Actitudes y Práctica en Salud , Promoción de la Salud , Humanos , Persona de Mediana Edad , Salud Pública , Derivación y Consulta
17.
Resusc Plus ; 5: 100076, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34223342

RESUMEN

AIMS: The primary aim of this study is to investigate whether out-of-hospital cardiac arrest (OHCA) survivors have lower levels of self-reported physical activity compared to a non-cardiac arrest (CA) control group who had acute myocardial infarction (MI). Additional aims are to explore potential predictors of physical inactivity (older age, female gender, problems with general physical function, global cognition, mental processing speed/attention, anxiety symptoms, depression symptoms, kinesiophobia, fatigue), and to investigate the relationship between self-reported and objectively measured physical activity among OHCA-survivors. METHODS: The Targeted Hypothermia versus Targeted Normothermia after Out-of-Hospital Cardiac Arrest trial (TTM2-trial) collects information regarding age, gender, self-reported physical activity, general physical function, global cognition and mental processing speed/attention at 6 months after OHCA. In this TTM2-trial cross-sectional prospective sub-study, participants at selected sites are invited to an additional follow-up meeting within 4 weeks from the main study follow-up. At this meeting, information regarding anxiety symptoms, depression symptoms, kinesiophobia and fatigue is collected. The OHCA-survivors are then provided with an objective measure of physical activity, a hip-placed accelerometer, to wear for one week, together with a training diary. At the end of the week, participants are asked to once again answer two self-reported questions regarding physical activity for that specific week. MI-controls attend a single follow-up meeting and perform the same assessments as the OHCA-survivors, except from wearing the accelerometer. We aim to include 110 OHCA-survivors and 110 MI-controls in Sweden, Denmark and the United Kingdom. CONCLUSION: The results from this sub-study will provide novel information about physical activity among OHCA-survivors. TRIAL REGISTRATION: Registered at ClinicalTrials.gov: NCT03543332, date of registration June 1, 2018.

18.
Lancet ; 397(10282): 1351-1362, 2021 04 10.
Artículo en Inglés | MEDLINE | ID: mdl-33798499

RESUMEN

BACKGROUND: A new variant of SARS-CoV-2, B.1.1.7, emerged as the dominant cause of COVID-19 disease in the UK from November, 2020. We report a post-hoc analysis of the efficacy of the adenoviral vector vaccine, ChAdOx1 nCoV-19 (AZD1222), against this variant. METHODS: Volunteers (aged ≥18 years) who were enrolled in phase 2/3 vaccine efficacy studies in the UK, and who were randomly assigned (1:1) to receive ChAdOx1 nCoV-19 or a meningococcal conjugate control (MenACWY) vaccine, provided upper airway swabs on a weekly basis and also if they developed symptoms of COVID-19 disease (a cough, a fever of 37·8°C or higher, shortness of breath, anosmia, or ageusia). Swabs were tested by nucleic acid amplification test (NAAT) for SARS-CoV-2 and positive samples were sequenced through the COVID-19 Genomics UK consortium. Neutralising antibody responses were measured using a live-virus microneutralisation assay against the B.1.1.7 lineage and a canonical non-B.1.1.7 lineage (Victoria). The efficacy analysis included symptomatic COVID-19 in seronegative participants with a NAAT positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to vaccine received. Vaccine efficacy was calculated as 1 - relative risk (ChAdOx1 nCoV-19 vs MenACWY groups) derived from a robust Poisson regression model. This study is continuing and is registered with ClinicalTrials.gov, NCT04400838, and ISRCTN, 15281137. FINDINGS: Participants in efficacy cohorts were recruited between May 31 and Nov 13, 2020, and received booster doses between Aug 3 and Dec 30, 2020. Of 8534 participants in the primary efficacy cohort, 6636 (78%) were aged 18-55 years and 5065 (59%) were female. Between Oct 1, 2020, and Jan 14, 2021, 520 participants developed SARS-CoV-2 infection. 1466 NAAT positive nose and throat swabs were collected from these participants during the trial. Of these, 401 swabs from 311 participants were successfully sequenced. Laboratory virus neutralisation activity by vaccine-induced antibodies was lower against the B.1.1.7 variant than against the Victoria lineage (geometric mean ratio 8·9, 95% CI 7·2-11·0). Clinical vaccine efficacy against symptomatic NAAT positive infection was 70·4% (95% CI 43·6-84·5) for B.1.1.7 and 81·5% (67·9-89·4) for non-B.1.1.7 lineages. INTERPRETATION: ChAdOx1 nCoV-19 showed reduced neutralisation activity against the B.1.1.7 variant compared with a non-B.1.1.7 variant in vitro, but the vaccine showed efficacy against the B.1.1.7 variant of SARS-CoV-2. FUNDING: UK Research and Innovation, National Institute for Health Research (NIHR), Coalition for Epidemic Preparedness Innovations, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midlands NIHR Clinical Research Network, and AstraZeneca.


Asunto(s)
Anticuerpos Neutralizantes/sangre , Vacunas contra la COVID-19/inmunología , COVID-19/prevención & control , COVID-19/virología , SARS-CoV-2/inmunología , Adolescente , Adulto , COVID-19/epidemiología , Prueba de Ácido Nucleico para COVID-19 , Vacunas contra la COVID-19/efectos adversos , ChAdOx1 nCoV-19 , Femenino , Humanos , Masculino , Persona de Mediana Edad , Técnicas de Amplificación de Ácido Nucleico , Pandemias/prevención & control , Método Simple Ciego , Reino Unido/epidemiología , Carga Viral , Adulto Joven
19.
Lancet ; 397(10277): 881-891, 2021 03 06.
Artículo en Inglés | MEDLINE | ID: mdl-33617777

RESUMEN

BACKGROUND: The ChAdOx1 nCoV-19 (AZD1222) vaccine has been approved for emergency use by the UK regulatory authority, Medicines and Healthcare products Regulatory Agency, with a regimen of two standard doses given with an interval of 4-12 weeks. The planned roll-out in the UK will involve vaccinating people in high-risk categories with their first dose immediately, and delivering the second dose 12 weeks later. Here, we provide both a further prespecified pooled analysis of trials of ChAdOx1 nCoV-19 and exploratory analyses of the impact on immunogenicity and efficacy of extending the interval between priming and booster doses. In addition, we show the immunogenicity and protection afforded by the first dose, before a booster dose has been offered. METHODS: We present data from three single-blind randomised controlled trials-one phase 1/2 study in the UK (COV001), one phase 2/3 study in the UK (COV002), and a phase 3 study in Brazil (COV003)-and one double-blind phase 1/2 study in South Africa (COV005). As previously described, individuals 18 years and older were randomly assigned 1:1 to receive two standard doses of ChAdOx1 nCoV-19 (5 × 1010 viral particles) or a control vaccine or saline placebo. In the UK trial, a subset of participants received a lower dose (2·2 × 1010 viral particles) of the ChAdOx1 nCoV-19 for the first dose. The primary outcome was virologically confirmed symptomatic COVID-19 disease, defined as a nucleic acid amplification test (NAAT)-positive swab combined with at least one qualifying symptom (fever ≥37·8°C, cough, shortness of breath, or anosmia or ageusia) more than 14 days after the second dose. Secondary efficacy analyses included cases occuring at least 22 days after the first dose. Antibody responses measured by immunoassay and by pseudovirus neutralisation were exploratory outcomes. All cases of COVID-19 with a NAAT-positive swab were adjudicated for inclusion in the analysis by a masked independent endpoint review committee. The primary analysis included all participants who were SARS-CoV-2 N protein seronegative at baseline, had had at least 14 days of follow-up after the second dose, and had no evidence of previous SARS-CoV-2 infection from NAAT swabs. Safety was assessed in all participants who received at least one dose. The four trials are registered at ISRCTN89951424 (COV003) and ClinicalTrials.gov, NCT04324606 (COV001), NCT04400838 (COV002), and NCT04444674 (COV005). FINDINGS: Between April 23 and Dec 6, 2020, 24 422 participants were recruited and vaccinated across the four studies, of whom 17 178 were included in the primary analysis (8597 receiving ChAdOx1 nCoV-19 and 8581 receiving control vaccine). The data cutoff for these analyses was Dec 7, 2020. 332 NAAT-positive infections met the primary endpoint of symptomatic infection more than 14 days after the second dose. Overall vaccine efficacy more than 14 days after the second dose was 66·7% (95% CI 57·4-74·0), with 84 (1·0%) cases in the 8597 participants in the ChAdOx1 nCoV-19 group and 248 (2·9%) in the 8581 participants in the control group. There were no hospital admissions for COVID-19 in the ChAdOx1 nCoV-19 group after the initial 21-day exclusion period, and 15 in the control group. 108 (0·9%) of 12 282 participants in the ChAdOx1 nCoV-19 group and 127 (1·1%) of 11 962 participants in the control group had serious adverse events. There were seven deaths considered unrelated to vaccination (two in the ChAdOx1 nCov-19 group and five in the control group), including one COVID-19-related death in one participant in the control group. Exploratory analyses showed that vaccine efficacy after a single standard dose of vaccine from day 22 to day 90 after vaccination was 76·0% (59·3-85·9). Our modelling analysis indicated that protection did not wane during this initial 3-month period. Similarly, antibody levels were maintained during this period with minimal waning by day 90 (geometric mean ratio [GMR] 0·66 [95% CI 0·59-0·74]). In the participants who received two standard doses, after the second dose, efficacy was higher in those with a longer prime-boost interval (vaccine efficacy 81·3% [95% CI 60·3-91·2] at ≥12 weeks) than in those with a short interval (vaccine efficacy 55·1% [33·0-69·9] at <6 weeks). These observations are supported by immunogenicity data that showed binding antibody responses more than two-fold higher after an interval of 12 or more weeks compared with an interval of less than 6 weeks in those who were aged 18-55 years (GMR 2·32 [2·01-2·68]). INTERPRETATION: The results of this primary analysis of two doses of ChAdOx1 nCoV-19 were consistent with those seen in the interim analysis of the trials and confirm that the vaccine is efficacious, with results varying by dose interval in exploratory analyses. A 3-month dose interval might have advantages over a programme with a short dose interval for roll-out of a pandemic vaccine to protect the largest number of individuals in the population as early as possible when supplies are scarce, while also improving protection after receiving a second dose. FUNDING: UK Research and Innovation, National Institutes of Health Research (NIHR), The Coalition for Epidemic Preparedness Innovations, the Bill & Melinda Gates Foundation, the Lemann Foundation, Rede D'Or, the Brava and Telles Foundation, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midland's NIHR Clinical Research Network, and AstraZeneca.


Asunto(s)
Vacunas contra la COVID-19/administración & dosificación , Vacunas contra la COVID-19/inmunología , COVID-19/prevención & control , Esquemas de Inmunización , Inmunización Secundaria , Adolescente , Adulto , Anciano , Formación de Anticuerpos , Infecciones Asintomáticas , Vacunas contra la COVID-19/efectos adversos , ChAdOx1 nCoV-19 , Humanos , Persona de Mediana Edad , Ensayos Clínicos Controlados Aleatorios como Asunto , SARS-CoV-2/inmunología , Adulto Joven
20.
mBio ; 12(1)2021 01 12.
Artículo en Inglés | MEDLINE | ID: mdl-33436429

RESUMEN

Colonization of the upper respiratory tract with Streptococcus pneumoniae is the precursor of pneumococcal pneumonia and invasive disease. Following exposure, however, it is unclear which human immune mechanisms determine whether a pathogen will colonize. We used a human challenge model to investigate host-pathogen interactions in the first hours and days following intranasal exposure to Streptococcus pneumoniae Using a novel home sampling method, we measured early immune responses and bacterial density dynamics in the nose and saliva after volunteers were experimentally exposed to pneumococcus. Here, we show that nasal colonization can take up to 24 h to become established. Also, the following two distinct bacterial clearance profiles were associated with protection: nasal clearers with immediate clearance of bacteria in the nose by the activity of pre-existent mucosal neutrophils and saliva clearers with detectable pneumococcus in saliva at 1 h post challenge and delayed clearance mediated by an inflammatory response and increased neutrophil activity 24 h post bacterial encounter. This study describes, for the first time, how colonization with a bacterium is established in humans, signifying that the correlates of protection against pneumococcal colonization, which can be used to inform design and testing of novel vaccine candidates, could be valid for subsets of protected individuals.IMPORTANCE Occurrence of lower respiratory tract infections requires prior colonization of the upper respiratory tract with a pathogen. Most bacterial infection and colonization studies have been performed in murine and in vitro models due to the current invasive sampling methodology of the upper respiratory tract, both of which poorly reflect the complexity of host-pathogen interactions in the human nose. Self-collecting saliva and nasal lining fluid at home is a fast, low-cost, noninvasive, high-frequency sampling platform for continuous monitoring of bacterial encounter at defined time points relative to exposure. Our study demonstrates for the first time that, in humans, there are distinct profiles of pneumococcal colonization kinetics, distinguished by speed of appearance in saliva, local phagocytic function, and acute mucosal inflammatory responses, which may either recruit or activate neutrophils. These data are important for the design and testing of novel vaccine candidates.


Asunto(s)
Infecciones Neumocócicas/microbiología , Sistema Respiratorio/microbiología , Streptococcus pneumoniae/crecimiento & desarrollo , Streptococcus pneumoniae/inmunología , Adolescente , Adulto , Animales , Citocinas , Interacciones Huésped-Patógeno , Humanos , Cinética , Ratones , Persona de Mediana Edad , Neutrófilos , Nariz/microbiología , Vacunas Neumococicas/inmunología , Neumonía Neumocócica/inmunología , Neumonía Neumocócica/microbiología , Sistema Respiratorio/inmunología , Saliva/microbiología , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/aislamiento & purificación , Adulto Joven
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