Immunogenicity of Two Doses of BNT162b2 mRNA COVID-19 Vaccine with a ChAdOx1-S Booster Dose among Navy Personnel in Mexico.

Booster doses of the SARS-CoV-2 vaccine have been recommended to improve and prolong immunity, address waning immunity over time, and contribute to the control of the COVID-19 pandemic. A heterologous booster vaccine strategy may offer advantages over a homologous approach. To compare the immunogenicity of two doses of BNT162b2 mRNA COVID-19 vaccine with a ChAdOx1-S booster dose, immunoglobulin G (IgG) anti-spike (anti-S) and anti-nucleocapsid (anti-N) antibody titers (Ab) were compared over 1 year and post-booster vaccination. Results showed that, at 3- to 9-month assessments in vaccinated subjects, an-ti-N Ab were undetectable in participants with no history of COVID-19. In contrast, anti-S Ab measurements were lower than those with COVID-19, and a decrease was observed during the 9 months of observation. After booster vaccination, no differences were found in anti-S between participants who reported a history of COVID-19 and those who did not. Anti-S levels were higher after booster vaccination measurement vs. at 9 months in participants with COVID-19 and without COVID-19, i.e., independent of an infection history. Vaccine administration elicited a response of higher anti-S IgG levels in those infected before vaccination, although levels decreased during the first nine months. IgG anti-N titers were higher in participants with a history of declared infection and who were asymptomatic. The ChAdOx1-S booster increased anti-S Ab levels in participants regardless of whether they had been infected or not to a significantly higher value than with the first two vaccines. These findings underscore the importance of booster vaccination in eliciting a robust and sustained immune response against COVID-19, regardless of the prior infection status.

Convalescent Plasma to Treat COVID-19: A Two-Center, Randomized, Double-Blind Clinical Trial.

Background: The use of convalescent plasma (CP) has been considered for its immunological mechanisms that could benefit patients in moderate and severe stages of COVID-19. This study evaluated the safety and efficacy of the use of donor CP for COVID-19. Material and methods: A double-blind, randomized controlled clinical trial was conducted from May to October 2020. Thirty-nine participants with moderate (II) and severe (III) stages of COVID-19 confirmed by RT-PCR were included. The study randomization rate was set at 3:1. CPs were chosen for application with a neutralizing antibody titer of ≥1:32. Results: We observed a significantly lower 21-day post-transfusion mortality HR: 0.17 (95.0% CI [0.07−0.45, p < 0.001]) in the group receiving CP compared with the control group; protective units (PU) in the group receiving convalescent plasma after seven days were significantly higher (512 (32−16,384) vs. 96 (32−256), p = 0.01); the PAO2/FIO2 index showed a significant improvement in the group receiving CP (251.01 (109.4) vs. 109.2 (62.4), p < 0.001, in the control group). Conclusion: CP is safe and effective, as it decreased mortality in the CP group compared with the control group.

Idarucizumab to revert the anticoagulant effect of dabigatran in traumatic acute subdural haematoma: a case report of first use in Latin America.

BACKGROUND: Direct oral anticoagulants (DOAC) are an attractive alternative over vitamin K antagonists. They have several advantages in primary and secondary prevention of thromboembolisms due to atrial fibrillation, as well as in prevention and treatment of thromboembolic venous disease. They have fast onset action, do not need laboratory controls in patients with normal renal function, and they have practically no interference with the patient's diet or medications. The strongest objection to their use was the lack of reversal agents that could be used in case of life-threatening haemorrhage or the need for emergency surgery. Dabigatran was the first DOAC to have its own specific reversal agent: idarucizumab, a monoclonal antibody. CASE SUMMARY: We report here the case of a patient undergoing treatment with dabigatran that suffered an expansive subdural haematoma secondary to a cranial injury. The condition was life-threatening and required emergency surgery. Anticoagulation was successfully reversed with idarucizumab. DISCUSSION: Emergency surgery in patients in treatment with DOAC is associated with an increased risk of bleeding. With the use of a specific antidote to block the action of the anticoagulant, as in the case of idarucizumab with dabigatran, the risk of complications during and after emergency surgery is reduced. This is the first case report with which the successful use of idarucizumab in Latin America is documented.

Resource Utilization and Costs Associated With Percutaneous Coronary Intervention When Treating Patients With Acute Coronary Syndrome in the Mexican National Institute of Cardiology "Ignacio Chávez".

BACKGROUND: The treatment of acute coronary syndrome (ACS) using percutaneous coronary intervention (PCI) is a frequent intervention with a high economic impact. OBJECTIVE: This study investigates the resource use and cost of PCI in Mexico where heart disease is a leading cause of death, and a large segment of the population does not have formal healthcare coverage. METHODS: This retrospective observational study obtained resource utilization data from patient files and itemized costs from the pharmacy registry at the National Institute of Cardiology. Patients were aged >18 years, diagnosed with ACS, and treated with PCI and secondary prophylaxis with aspirin plus clopidogrel or prasugrel. Patients had a follow-up of >12 months at the institute. Statistical analysis was descriptive. RESULTS: The sample included 156 patients (mean age: 58.66 years; male: 77.9%). Patients were diagnosed with ST segment elevation myocardial infarction (STEMI), non-ST segment elevation myocardial infarction, and unstable angina 64.9%, 27.2%, and 7.9%, respectively. The mean (standard deviation [SD]) total medical cost was estimated to be $145 677 ($98 326) Mexican pesos 2018. The highest category of spending was surgical materials (mean [SD]: $47 834 [$32 569], comprising 32.8% of total costs); medications and access to the operating room represented 14.2% and 11.8%, respectively. Mean (SD) hospital stay was 9.07 (6.2) days; for the 11.5% of patients admitted to the intensive care unit, the mean (SD) stay was 4.61 (2.06) days. The mean cost of standard hospitalization was $12 572, or 8.6% of spending; intensive care unit hospitalization comprised 17.7% of total costs (mean: $25 802). The cost of the intervention is subsidized up to 95% for patients with a low social economic status, with the exception of surgical materials such as stents. This results in the highest burden component of the intervention being placed on the patient and not the institute. CONCLUSION: The mean cost per patient shows that PCI is an expensive procedure in Mexico. A lack of subsidies for surgical equipment places a high economic burden on the patient and represents a barrier of access for a vulnerable population that likely increases mortality and morbidity rates in those patients unable to pay for treatment and a potential high burden of debt for those who do pay.

[Decrease of total hemorrhage with reduced doses of enoxaparin in high risk unstable angina. ENHNFAI study. (Enoxaparin vs non-fractionated heparin in unstable angina). Preliminary report]. / Disminución de hemorragias totales con dosis reducidas de enoxaparina en angina inestable de alto riesgo. Estudio ENHNFAI. (ENoxaparina vs Heparina No Fraccionada en Angina inestable). Informe preliminar.

UNLABELLED: In this prospective, randomized and controlled study, we compare complications in 2 groups of patients: group 1, enoxaparin 0.8 mg/kg, subcutaneous every 12 hours during 5 days, and group 2, intravenous unfractionated heparin during 5 days, by infusion treated to activate partial tromboplastin time 1.5-2 the upper limit of normal. Blood samples were obtained at 4, 12, 24 hours and at day 5 of treatment, to measure anti-Xa levels, and also, evaluated end points at 30 days, between groups. Univariate and multivariate logistic regression analyses were performed with clinical and angiographic variables between groups, with p < 0.05. RESULTS: 203 consecutive patients, average age of 60.5 +/- 11.2 years, and 80% men, were included. There were no differences in clinical and angiographic characteristics. All patients with enoxaparin had therapeutic levels of anti-Xa, of 0.5 to 0.67 U/mL. There was increasing risk of total bleeding in group 2 (18.7%) than in group 1 (5.6%), with RR = 1.72 (95% CI 1.29, 2.29), p = .003. Also, there was 33.3% of MACE in group 2, and only 17.8% in group 1, with RR = 1.88 (CI 95% 1.29, 2.29), p = .011. CONCLUSIONS: 1) Low doses of enoxaparine achieve therapeutic levels, since the first 4 hours of treatment. 2) A significant reduction of total bleeding occurred with the low doses of enoxaparin, with the same efficacy to reduce MACE during follow-up.