Population homogeneity for the antibody response to COVID-19 BNT162b2/Comirnaty vaccine is only reached after the second dose across all adult age ranges

While mRNA vaccines are administrated worldwide in an effort to contain the COVID-19 pandemic, the heterogeneity of the humoral immune response they induce at the population scale remains unclear. Here, in a prospective, longitudinal, cohort-study, including 1245 hospital care workers and 146 nursing home residents scheduled for BNT162b2 vaccination, together covering adult ages from 19 to 99 years, we analyse seroconversion to SARS-CoV-2 spike protein and amount of spike-specific IgG, IgM and IgA before vaccination, and 3-5 weeks after each dose. We show that immunogenicity after a single vaccine dose is biased to IgG, heterogeneous and reduced with increasing age. The second vaccine dose normalizes IgG seroconversion in all age strata. These findings indicate two dose mRNA vaccines is required to reach population scale humoral immunity. The results advocate for the interval between the two doses not to be extended, and for serological monitoring of elderly and immunosuppressed vaccinees.

Characterising activity and diet compositions for dementia prevention: protocol for the ACTIVate prospective longitudinal cohort study

IntroductionApproximately 40% of late-life dementia may be prevented by addressing modifiable risk factors, including physical activity and diet. Yet, it is currently unknown how multiple lifestyle factors interact to influence cognition. The ACTIVate Study aims to (1) explore associations between 24-hour time-use and diet compositions with changes in cognition and brain function; and (2) identify duration of time-use behaviours and the dietary compositions to optimise cognition and brain function.Methods and analysisThis 3-year prospective longitudinal cohort study will recruit 448 adults aged 60–70 years across Adelaide and Newcastle, Australia. Time-use data will be collected through wrist-worn activity monitors and the Multimedia Activity Recall for Children and Adults. Dietary intake will be assessed using the Australian Eating Survey food frequency questionnaire. The primary outcome will be cognitive function, assessed using the Addenbrooke’s Cognitive Examination-III. Secondary outcomes include structural and functional brain measures using MRI, cerebral arterial pulse measured with diffuse optical tomography, neuroplasticity using simultaneous transcranial magnetic stimulation and electroencephalography, and electrophysiological markers of cognitive control using event-related potential and time frequency analyses. Compositional data analysis, testing for interactions between time point and compositions, will assess longitudinal associations between dependent (cognition, brain function) and independent (time-use and diet compositions) variables.ConclusionsThe ACTIVate Study will be the first to examine associations between time-use and diet compositions, cognition and brain function. Our findings will inform new avenues for multidomain interventions that may more effectively account for the co-dependence between activity and diet behaviours for dementia prevention.Ethics and disseminationEthics approval has been obtained from the University of South Australia’s Human Research Ethics committee (202639). Findings will be disseminated through peer-reviewed manuscripts, conference presentations, targeted media releases and community engagement events.Trial registration numberAustralia New Zealand Clinical Trials Registry (ACTRN12619001659190).

Long-term use of CPAP in patients with obstructive sleep apnea: a prospective longitudinal cohort study

Continuous positive airway pressure (CPAP) is an efficient treatment for obstructive sleep apnea (OSA). Reports of long-term usage vary, as do the factors that predict long-term usage. The aim of this study was to explore long-term CPAP usage and identify potential predictors. This prospective longitudinal cohort study included all patients referred to an outpatient clinic for CPAP treatment during an eight-month period. Clinical data were collected at baseline. Follow-ups were scheduled after one week, three months and two years. Use data were downloaded from the CPAP device at each follow-up. Of 163 included patients, 112 were available for long-term follow-up 2–4 years after starting CPAP, and use data were downloaded for 99 patients. Median duration of CPAP use was 6 h/night (IQR 4.2–7.1). The only significant variable predicting long-term usage was usage at three months. Nearly half (43%) of the patients needed extra consultations beyond the standard treatment plan. Most patients (69%) did not contact the clinic for their recommended two-year follow-up but were instead called into the clinic specifically for the study. There was no significant difference in long-term CPAP usage between patients who initiated contact themselves and those who were called in and would otherwise have been lost for follow-up. Most patients adhere well to CPAP in the long term, although many need extra follow-up. Patients lost for follow-up should not necessarily be considered non-adherent as their reason for not attending could be that they are managing treatment well on their own.

Outcomes of gastrointestinal fistulas: Results from a multi-continent, multi-national, multi-center cohort

SUMMARYRationaleGastrointestinal fistulas (GIF) represent a severe and potentially lethal complication of the hospital surgical activity. However, evidences are lacking about prognosis and outcomes of GIF in Latin America (LATAM) hospitals.ObjectiveTo describe the prognosis and outcomes GIF in LATAM hospitals.Study designProspective, longitudinal, cohort-type study. The cohort fostered three cross-sectional examinations: First examination: On admission of the patient in the study; Second examination: Thirty days later; and Third (and last) examination: Sixty days after patient’s admission.Study serieOne hundred seventy-seven patients (Males: 58.2 %; Average age: 51.0 ± 16.7 years; Ages ≥ 60 years: 36.2 %) diagnosed with, and assisted for, GIF (ECF: Enterocutaneous: 64.9 % vs. EAF: Enteroathmospheric: 35.1 %) in 76 LATAM hospitals (13 countries) and Europe (4).MethodsCondition (Alive vs. Deceased) and hospital status (Hospitalized vs. Discharged) of the patient, and the GFI patency (Closed vs. Non closed) were recorded in each of the cohort’s examination. Indicators of GFI prognosis thus constructed were correlated demographical, sanitary, surgical and nutritional characteristics of the patientsResultsOn conclusion of the study indicators of GIF prognosis behaved as follows: Mortality:14.7 %; Prolonged hospitalization: 47.4 %; Spontaneous closure of GIF: 36.2 %. Type of GIF influenced upon patient’s survival: ECF: 87.0 % vs. EAF: 82.3 % (Δ = +4.7 %; χ2 = 6.787; p < 0.05). In each examination of the cohort, the number of surviving subjects was always greater among those with ECF: After 30 days: ECF: 92.1 % vs. EAF: 83.9 % (Δ = +8.2 %); After 60 days: ECF: 98.1 % vs. EAF: 90.4 % (Δ = +7.7 %; χ2 = 13.764; p < 0.05). On the other hand, hospital stay was prolonged in the subjects of elective surgery (Elective surgery: 61.4 % vs. Emergency surgery: 38.3 % (Δ = +23.1 %; χ2 = 9.064; p < 0.05) and those with a reduced calf circumference (χ2 = 12.655; p < 0.05). Location of the fistula also influenced upon prolongation of hospital stay (χ2 = 7.817; p < 0.05).ConclusionsType of GIF influences upon survival of the patient. On the hand, hospital stay was dependent upon type of surgery previously performed, location of the fistula, and calf circumference value on admission in the study serie.