Most COVID-19 vaccines require two doses, however with limited vaccine supply, policymakers are considering single-dose vaccination as an alternative strategy. Using a mathematical model combined ...with optimization algorithms, we determined optimal allocation strategies with one and two doses of vaccine under various degrees of viral transmission. Under low transmission, we show that the optimal allocation of vaccine vitally depends on the single-dose efficacy. With high single-dose efficacy, single-dose vaccination is optimal, preventing up to 22% more deaths than a strategy prioritizing two-dose vaccination for older adults. With low or moderate single-dose efficacy, mixed vaccination campaigns with complete coverage of older adults are optimal. However, with modest or high transmission, vaccinating older adults first with two doses is best, preventing up to 41% more deaths than a single-dose vaccination given across all adult populations. Our work suggests that it is imperative to determine the efficacy and durability of single-dose vaccines, as mixed or single-dose vaccination campaigns may have the potential to contain the pandemic much more quickly.
Trial results for two COVID-19 vaccines suggest at least 90% efficacy against symptomatic disease (VE
). It remains unknown whether this efficacy is mediated by lowering SARS-CoV-2 infection ...susceptibility (VE
) or development of symptoms after infection (VE
). We aim to assess and compare the population impact of vaccines with different efficacy profiles (VE
and VE
) satisfying licensure criteria. We developed a mathematical model of SARS-CoV-2 transmission, calibrated to data from King County, Washington. Rollout scenarios starting December 2020 were simulated with combinations of VE
and VE
resulting in up to 100% VE
. We assumed no reduction of infectivity upon infection conditional on presence of symptoms. Proportions of cumulative infections, hospitalizations and deaths prevented over 1 year from vaccination start are reported. Rollouts of 1 M vaccinations (5000 daily) using vaccines with 50% VE
are projected to prevent 23-46% of infections and 31-46% of deaths over 1 year. In comparison, vaccines with 90% VE
are projected to prevent 37-64% of infections and 46-64% of deaths over 1 year. In both cases, there is a greater reduction if VE
is mediated mostly by VE
. The use of a "symptom reducing" vaccine will require twice as many people vaccinated than a "susceptibility reducing" vaccine with the same 90% VE
to prevent 50% of the infections and death over 1 year. Delaying the start of the vaccination by 3 months decreases the expected population impact by more than 50%. Vaccines which prevent COVID-19 disease but not SARS-CoV-2 infection, and thereby shift symptomatic infections to asymptomatic infections, will prevent fewer infections and require larger and faster vaccination rollouts to have population impact, compared to vaccines that reduce susceptibility to infection. If uncontrolled transmission across the U.S. continues, then expected vaccination in Spring 2021 will provide only limited benefit.
To conduct a systematic review and meta-analyses on short-term outcomes between total hip arthroplasty (THA) through direct anterior approach (DAA) compared to THA through conventional approaches ...(CAs) in treatment of hip diseases and fractures. We performed a systematic literature search up to March 1, 2021 to identify RCTs, comparing THA through DAA with THA through CAs. We calculated mean differences (MDs) with 95% confidence intervals (CIs) for continuous outcomes, using the DerSimonian and Laird method and a random effects model. We calculated odds ratios (ORs) with 95% CIs for dichotomous outcomes, using the Mantel-Haenszel method and a random effects model. Ten RCTs met the criteria for final meta-analysis, involving 1053 patients. Four studies were blinded RCTs with a level I evidence, the other 6 studies were non-blinded RCTs with a level II evidence. DAA had a longer operation time than CAs (MD = 17.8, 95% CI 4.8 to 30.8); DAA had similar results compared to CAs for incision length (MD = - 1.1, 95% CI - 4.1 to 1.8), for intraoperative blood loss (MD = 67.2, 95% CI - 34.8 to 169.1), for HHS 3 months postoperatively (MD = 2.4, 95% CI - 0.7 to 5.5), for HHS 6 months postoperatively (MD = 0.8, 95% CI - 1.9 to 3.5), for HHS 12 months postoperatively (MD = 0.9, 95% CI - 0.7 to 2.5), for pain VAS 1 day postoperatively (MD = - 0.9, 95% CI - 2.0 to 0.15), for acetabular cup anteversion angle (MD = - 4.3, 95% CI - 5.2 to - 3.5), for acetabular cup inclination angle (MD = - 0.5, 95% CI - 2.1 to 1.1) and for postoperative complications (OR = 2.4, 95% CI 0.5 to 12.4). Considering the overall results of our meta-analysis, we can conclude that THA through DAA showed similar short-term surgical, functional, radiological outcomes and postoperative complications compared to THA through CAs.
•Two cases of laparoscopic splenectomy for solitary metastasis – patients after open surgery.•Operative time was 165–200 min, patients were discharged on POD 3–4.•Laparoscopic splenectomy is feasible ...after open surgery.
Solitary splenic metastases are a rare entity.
We report two consecutive cases of solitary splenic metastases from ovarian and rectal cancer which were completely removed by laparoscopic splenectomy in patients with previous open surgery. The operative time was 165–200 min. The blood loss was 25–100 ml. There were no intra- and postoperative complications.
Laparoscopic splenectomy for solitary splenic metastases seems safe and feasible with short recovery period even in patients with previous open surgery. More research in the area is needed.
The aim was to conduct a systematic review of literature and meta-analysis of randomized controlled trials (RCTs) comparing short-term outcomes of bipolar hemiarthroplasty (HA) through SuperPATH and ...bipolar HA through conventional approaches (CAs) in patients with femoral neck fractures. The following PICO question was formulated: In human participants with femoral neck fractures, are the short-term outcomes of SuperPATH HA better than the short-term outcomes of CAs HA? The following databases were searched until 25 August 2023: PubMed, CNKI, CENTRAL of The Cochrane Library, Clinical trials, and Google Scholar. Quality assessment of the RCTs was performed, according to the Cochrane's Risk of Bias 2 tool and the recommendations of the GRADE system. Furthermore, we evaluated publication bias with funnel plots. Mean differences (MDs) with 95% confidence intervals (CIs) were calculated for continuous variables using the Hartung-Knapp-Sidik-Jonkman method and a random effects model. Nine RCTs with overall 762 patients were included in this meta-analysis. All 9 RCTs were rated with a moderate risk of bias. The quality of evidence of the outcome parameters was rated moderate to very low. The funnel plots were overall broadly symmetrical, possibly indicating low to moderate publication bias. SuperPATH had a longer operation time compared to CAs (MD = 21.79, 95% CI 12.57 to 31.02). SuperPATH decreased incision length (MD = - 4.50; 95% CI - 5.80 to - 3.20), intraoperative blood loss (MD = - 103.96, 95% CI - 150.27 to - 55.66), postoperative drainage volume (MD = - 137.30, 95% CI - 178.74 to - 95.86), time to mobilization (MD = - 3.86; 95% CI - 5.96 to - 1.76), pain VAS ≤ 1 week postoperatively (MD = - 1.81; 95% CI - 2.17 to - 1.45), and hospitalization time (MD = - 4.05; 95% CI - 4.96 to - 3.15). SuperPATH improved HHS ≤ 1 week postoperatively (MD = 11.10; 95% CI 1.65 to 20.54) and HHS 3 months postoperatively (MD = 6.33; 95% CI 3.97 to 8.69). There was no difference in pain VAS 1-3 months postoperatively (MD = - 0.08; 95% CI - 0.22 to 0.05) and HHS 6 months postoperatively (MD = 0.44; 95% CI - 0.11 to 1.00). This is the first meta-analysis comparing SuperPATH HA with CAs HA in patients with femoral neck fractures. SuperPATH HA was superior in the early short-term functional outcome (HHS) compared to CAs HA, reaching minimal clinically important differences. Furthermore, SuperPATH HA showed significantly better results in incision length, blood loss, time to mobilization, pain intensity (VAS), and hospitalization time than CAs HA.
Cholera remains an important public health problem in major cities in Bangladesh, especially in slum areas. In response to growing interest among local policymakers to control this disease, this ...study estimated the impact and cost-effectiveness of preventive cholera vaccination over a ten-year period in a high-risk slum population in Dhaka to inform decisions about the use of oral cholera vaccines as a key tool in reducing cholera risk in such populations.
Assuming use of a two-dose killed whole-cell oral cholera vaccine to be produced locally, the number of cholera cases and deaths averted was estimated for three target group options (1-4 year olds, 1-14 year olds, and all persons 1+), using cholera incidence data from Dhaka, estimates of vaccination coverage rates from the literature, and a dynamic model of cholera transmission based on data from Matlab, which incorporates herd effects. Local estimates of vaccination costs minus savings in treatment costs, were used to obtain incremental cost-effectiveness ratios for one- and ten-dose vial sizes. Vaccinating 1-14 year olds every three years, combined with annual routine vaccination of children, would be the most cost-effective strategy, reducing incidence in this population by 45% (assuming 10% annual migration), and costing was $823 (2015 USD) for single dose vials and $591 (2015 USD) for ten-dose vials per disability-adjusted life year (DALY) averted. Vaccinating all ages one year and above would reduce incidence by >90%, but would be 50% less cost-effective ($894-1,234/DALY averted). Limiting vaccination to 1-4 year olds would be the least cost-effective strategy (preventing only 7% of cases and costing $1,276-$1,731/DALY averted), due to the limited herd effects of vaccinating this small population and the lower vaccine efficacy in this age group.
Providing cholera vaccine to slum populations in Dhaka through periodic vaccination campaigns would significantly reduce cholera incidence and inequities, and be especially cost-effective if all 1-14 year olds are targeted.
BACKGROUND:Randomized controlled trials (RCTs) suggest that the efficacy of tenofovir-based preexposure prophylaxis (PrEP) strongly depends on the consistency of PrEP use. We explore how the patterns ...of pill taking and waning of PrEP protection may affect PrEP efficacy for HIV prevention.
METHODS:A 2-arm RCT was simulated by mathematical models assuming that the prescribed daily doses were skipped periodically, randomly, or in large blocks. Risk-driven adherence, in which PrEP was taken when sex was expected, was also investigated. Three temporal PrEP protection profiles were exploredlong (5 days), intermediate (3 days), and short (24 hours). Modeling results were compared to the efficacy observed in completed RCTs.
RESULTS:The expected PrEP efficacy was 60% with periodic, 50% with random, and 34% with block adherence when PrEP had a long protection profile and pills were taken only 50% of the days. Risk-driven pill taking resulted in 29% and 37% daily pills taken and efficacy of 43% and 51%, respectively, for long protection. High PrEP efficacy comparable with that observed in Partners PrEP and Centers for Disease Control and Prevention Botswana trials was simulated under long protection, high overall adherence, and limited block pill taking; the moderate efficacy observed in iPrEx and Bangkok trials was comparable with the 50% adherence scenarios under random pill taking and long protection.
CONCLUSIONS:Pill-taking patterns may have a substantial impact on the protection provided by PrEP even when the same numbers of pills are taken. When PrEP retains protection for longer than a day, pill-taking patterns can explain a broad range of efficacies observed in PrEP RCTs.
Objective: To compare efficacy and safety of microbubble contrast agent (SonoVue) and transcatheter arterial chemoembolization (TACE) in combination with high-intensity focused ultrasound (HIFU) for ...treatment of patients with hepatocellular carcinoma (HCC).
Methods: According to our inclusion criteria, we retrospectively reviewed 52 patients with HCCs, and divided them into SonoVue group and TACE group. Tumors were examined by enhanced magnetic resonance imaging. Change of lesions, alpha-fetoprotein values, hepatic and renal function were measured pre- and postoperatively. Then, adverse events were observed and clinical follow-up was performed.
Results: Clinical efficacy and the majority of treatment parameters were similar, except for time and energy required for the first massive grey-scale changes in SonoVue group, which were significantly lower than those in TACE group (p < .05). For adverse events, only rate of fever (3.85%) in SonoVue group was significantly lower than that in TACE group (50.00%, p < .05). The 'diagnosis and treatment cycle' in SonoVue group (11.5 ± 2.9) was remarkably shorter than TACE group (22.7 ± 6.3, p < .05). Energy efficiency factor was positively correlated with distance from the deepest layer of lesion to the hepatic capsule or to the abdominal wall in SonoVue group, while that was negatively correlated with iodized oil deposition in TACE group.
Conclusion: Using microbubble (SonoVue) in HIFU procedure has a similar therapeutic effect compared with TACE, and does not increase the risk of treatment. It might present a new strategy in clinical treatment, especially for patients with a smaller diameter of HCC.
To evaluate the clinical usefulness of the microbubble contrast agent SonoVue in enhancing high-intensity focused ultrasound (HIFU) for the treatment of adenomyosis.
A total of 102 patients with ...adenomyosis, assessed from August 2015 to April 2017, were randomly divided into 1-minute (A) and 10-minute (B) groups, respectively. In groups A and B, HIFU started 1 minute and 10 minutes, respectively, after SonoVue injection. All patients underwent a magnetic resonance imaging scan before and after HIFU treatment.
The occurrence rates of massive gray scale change, nonperfused volume, and fractional ablation were similar in both groups (P > .05). Meanwhile, sonication time to massive gray scale change was reduced in group A compared with group B (P < .05). In addition, mean power, total energy, and energy efficiency factor were lower in group A than group B (all P < .05). The incidence rates of most perioperative and all postoperative adverse events were similar in both groups (P > .05). The incidence rates of pain in the treated region, leg pain, and sciatic or buttock pain during HIFU were substantially lower in group A than group B (P < .05).
Overall, starting HIFU sonication at 1 minute after SonoVue injection enhances HIFU ablation by cavitation and heating and is safe. Early massive gray scale change, lower total energy, and reduced mean power are potential safety factors.
Many diseases, such as HIV, are heterogeneous for risk. In this paper, we study an infectious-disease model for a population with demography, mass-action incidence, an arbitrary number of risk ...classes, and separable mixing. We complement our general analyses with two specific examples. In the first example, the mean of the components of the transmission coefficients decreases as we add more risk classes. In the second example, the mean stays constant but the variance decreases. For each example, we determine the disease-free equilibrium, the basic reproduction number, and the endemic equilibrium. We also characterize the spectrum of eigenvalues that determine the stability of the endemic equilibrium. For both examples, the basic reproduction number decreases as we add more risk classes. The endemic equilibrium, when present, is asymptotically stable. Our analyses suggest that risk structure must be modeled correctly, since different risk structures, with similar mean properties, can produce different dynamics.
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